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- AN-COR-014Corrosion Inhibitor Efficiency Measurement in Turbulent Flow Conditions with the Autolab Rotating Cylinder Electrode (RCE), According to ASTM G185
The rotating cylinder electrode (RCE) is a technique used in corrosion research to simulate in a laboratory environment the turbulent flow which usually occurs when liquids are transported through pipelines. The RCE is used to generate a turbulent flow at the surface of a sample, simulating the pipe flow conditions. Experiments that involve an RCE are regulated by the ASTM G185 standard. In this application note, The RCE with a 1018 carbon steel cylinder sample was used with the linear polarization (LP) measurement technique.
- AN-V-226Zinc in drinking water with a glassy carbon electrode
No health-based guideline value exists for zinc. However, to maintain good quality municipal drinking water, the United States Environmental Protection Agency (US-EPA) set a maximum concentration of 5 mg/L as the limit value. Typical concentrations in surface and ground waters are between 10–40 μg/L Zn, with values up to 1 mg/L in tap water. Anodic stripping voltammetry (ASV) on the ex-situ mercury film modified glassy carbon electrode provides a less complex alternative to atomic absorption spectroscopy (AAS) for zinc determination in drinking water.
- AN-V-221Cadmium and lead in drinking water with a Bi drop electrode
To reduce the toxic effects of cadmium on the human body, as well as to limit the neurotoxic effects of lead, the provisional guideline values in the World Health Organization’s «Guidelines for Drinking-water Quality» are set to a maximum concentration of 3 µg/L for cadmium and 10 µg/L for lead. The completely mercury-free Bi drop electrode takes the next step towards converting voltammetric analysis into a non-toxic approach for heavy metal detection. Using this environmentally friendly sensor for anodic stripping voltammetry (ASV) allows the simultaneous determination of Cd and Pb in drinking water. The outstanding sensitivity is more than sufficient to monitor the provisional WHO guideline values.
- AN-V-227Chromium(VI) in drinking water with a glassy carbon electrode
The guideline value for chromium in the World Health Organization’s (WHO) «Guidelines for Drinking-water Quality» is 50 µg/L. It should be noted here that chromium concentrations are often expressed as total chromium and not as chromium(III) or (VI). Chromium(VI) is responsible for changes in genetic material, and is found in significantly lower concentrations than Cr(III). Therefore an extremely sensitive method is required to monitor Cr(VI) in drinking water.The powerful adsorptive stripping voltammetry (AdSV) technique on the ex-situ mercury film modified glassy carbon electrode using DTPA as complexing agent can be used to determine such low concentrations.
- AN-V-225Cadmium and lead in drinking water with a glassy carbon electrode
To reduce the toxic effects of cadmium on the kidneys, skeleton, and the respiratory system, as well as the neurotoxic effects of lead, the provisional guideline values in the World Health Organization’s (WHO) «Guidelines for Drinking-water Quality» are set to a maximum concentration of 3 µg/L for cadmium and 10 µg/L for lead.The powerful anodic stripping voltammetry (ASV) technique on the ex-situ mercury film modified glassy carbon electrode is more than sufficient to monitor the proposed WHO guidelines for Cd and Pb in drinking water.
- AN-V-223Nickel and cobalt in drinking water with a Bi drop electrode
The main sources of nickel pollution are electroplating, metallurgical operations, or leaching from pipes and fittings. Catalysts for the petroleum and chemical industries are major application fields for cobalt. In both cases, the metal is either released directly, or via the waste water-river pathway into the drinking water system. Therefore in the EU the legislation specifies 20 µg/L as the limit value for the Ni concentration in drinking water.The simultaneous and straightforward determination of nickel and cobalt is based on adsorptive stripping voltammetry (AdSV). The unique properties of the non-toxic Bi drop electrode combined with AdSV results in an excellent performance in terms of sensitivity.
- AN-V-224Nickel and cobalt in drinking water with a glassy carbon electrode
Due to the toxicity and the detrimental effects of nickel and cobalt on human health, their concentrations in drinking water must be controlled. Therefore, EU the legislation specifies 20 µg/L as the limit value for nickel in drinking water. The current provisional guideline value for Ni in the World Health Organization’s «Guidelines for Drinking-water Quality» is set to a maximum concentration of 70 µg/L. To monitor the concentrations of Ni and Co with the 884 Professional VA, a method for simultaneous determination on the glassy carbon electrode (GC-RDE) modified with a Bi film is used.
- AN-EC-011Investigation of intermediates in the electrodeposition of copper using the Autolab rotating ring disc electrode (RRDE)
Copper is arguably one of the most technologically relevant metals, especially for the semiconductor industry. The deposition process used in this industry is known as the dual-damascene process and it involves the electrodeposition of copper from an acidic cupric compound, in the presence of additives.This Application Note illustrates the use of the Autolab rotating ring disc electrode (RRDE) for the study of electrodeposition of copper and the detection of the Cu+ intermediate.
- AN-EC-002Reference electrodes and their usage
A reference electrode has a stable and well-defined electrochemical potential (at constant temperature), against which the applied or measured potentials in an electrochemical cell are referred. A good reference electrode is therefore stable and non-polarizable. In other words, the potential of such an electrode will remain stable in the used environment and also upon the passage of a small current. This application note lists the most used reference electrodes, together with their range of use.
- AB-083Sodium analysis by ion-selective electrode
This document explains how to measure Na ion concentration in diverse matrices with a sodium ion-selective electrode (Na-ISE) using direct measurement and standard addition.
- AB-082Determination of fluoride with an ion-selective electrode
This Bulletin describes fluoride determination in various matrices with the help of the ion-selective fluoride electrode (F-ISE). The F-ISE is comprised of a lanthanum fluoride crystal and exhibits a response in accordance with the Nernst equation across a wide range of fluoride concentrations.The first part of this Bulletin contains notes regarding the handling and care of the electrode and the actual fluoride determination itself. The second part demonstrates the direct determination of fluoride with the standard addition technique in table salt, toothpaste and mouthwash.
- AN-T-071Determination of palladium using the «Ionic Surfactant» electrode
Determination of palladium(II) by potentiometric titration with hexadecylpyridinium chloride using the «Ionic Surfactant» electrode.
- AN-T-118Automatic determination of zinc and magnesium mixtures with ion-selective copper electrode (Cu ISE)
Zinc and magnesium ion mixtures are analyzed using back-titration at different pH values. The ion-selective copper electrode is used here as the indicator electrode. First, the zinc is determined in acidic solution and then the magnesium in alkali solution.
- AB-233Potentiometric determination of anionic and cationic surfactants with surfactant electrodes
Anionic surfactants can be titrated with cationic surfactants and vice-versa. The Bulletin describes a multitude of substances that can be determined in this fashion and specifies the respective working conditions and parameters. In contrast to the classic two-phase titration in accordance with Epton, the titration with the anionic and cationic surfactants electrodes can be performed without chloroform. Furthermore, the equivalence point of the titration is difficult to determine in some cases with the Epton method and the titration cannot be automated.In many cases, a surfactant ISE is a remedy that is both environmentally friendly and suitable here. It was developed specially for application with potentiometrically indicated surfactant determinations.
- WP-055Corrosion Best Practice – Creating Pipe-flow Conditions Using a Rotating Cylinder Electrode
Electrochemical measurements utilizing a rotating cylinder electrode (RCE) are widely used in industrial corrosion applications when simulation of realistic pipe conditions are necessary in a lab environment. This white paper allows further insight into the particularities and parameters which govern the electrochemical measurements, in particular measurements performed in turbulent flow conditions, and shows a complete picture of the best practice use of this technique. The annexes provide an overview and short explanation of the parameters and laws specific to the fluid behavior in electrochemical cells with RCE.
- AN-COR-015Corrosion Rates Measurements in Quiescent and Turbulent Flow conditions by using Rotating Cylinder Electrode (RCE)
The rotating cylinder electrode (RCE) is successfully used in a laboratory environment to generate a turbulent flow at the surface of a sample, simulating realistic pipe flow conditions. In this application note, the corrosion rate is measured and compared between quiescent and turbulent flow conditions, while keeping all the other experimental conditions unchanged. The linear polarization (LP) technique was used together with the RCE (with and without rotation).
- AB-305Check of surfactant electrodes
This Application Bulletin describes methods for checking the condition of electrodes for surfactant titration. For testing electrodes used for ionic surfactant titration (Ionic Surfactant electrodes), sodium dodecyl sulfate (SDS) is determined using TEGO®trant. Conversely, for testing electrodes used for cationic surfactant titration (Cationic Surfactant electrodes), TEGO®trant is titrated with SDS.For non-ionic surfactant electrodes (NIO surfactant electrode), PEG 1000 is titrated with sodium tetraphenylborate (STPB).For testing Surfactrode Resistant and Surfactrode Refill electrodes, titrations of SDS with TEGO®trant are performed. Suitable criteria for the test are the height of the potential jump and the shape of the titration curve.Key word: NaPh4B
- AB-025Coatings on silver electrodes
Ag electrodes are used for the indication of the potentiometric endpoints in precipitation titrations between silver and halide or sulfide ions. A coating on the silver ring may increase the sensitivity of the electrode and can thus reduce the limit of detection. This is why a variety of coated Ag electrodes are commercially available. This bulletin describes how the silver ring of Ag electrodes can be coated with AgCl, AgBr, AgI or Ag2S by electrolysis.
- AB-048Check of Silver, Platinum and Gold electrodes
It is essential to know before starting the sample analysis if the electrode is in a good state or not. A well workingelectrode will increase the quality of your results, as the accuracy and precision will be increased. Furthermore, tedious error tracking can be omitted and no sample is wasted due to a defect or old electrode. There exist several ways how to check metal electrodes, e.g., measurement of redox potentials, potentiometric titration or bivoltammetric titration. This bulletin describes the best methods for the various by Metrohm available metal electrodes.
- AN-EC-030Electrochemistry of microelectrodes: a comparison with common-size electrodes
In this Application Note, the electrochemical properties of electrodes with a micrometer-size surface area are compared with the electrochemical properties of electrodes with millimeter-size surface area. The comparison is made through cyclic voltammetry in a Fe3+/Fe2+ (ferro/ferri) solution, and the differences in the voltammograms are explained with the different diffusion profiles at the electrode-electrolyte interface.
- AN-EC-014Oxygen Reduction Reaction with the Rotating Ring Disk Electrode
The oxygen reduction reaction (ORR) is important to the functional readiness of a fuel cell. Rotating ring disk electrode (RRDE) experiments allow the reaction to be studied in hydrodynamic conditions to determine kinetic properties via the Levich and Koutecký-Levich equations. Mechanistic information is simultaneously obtained from the reaction of intermediates at the secondary (ring) electrode. This application note describes how the RRDE from Metrohm Autolab can be used to study the ORR.
- AN-EC-027Measuring the potential at the counter electrode with VIONIC powered by INTELLO
Many different configurations are made possible when using two-, three-, or four-electrode cell setups in research. Depending on the experimental requirements, one setup may be preferred over another. Therefore, the proper electrode arrangements for these three situations are defined in this Application Note. As an example, the potential at the counter electrode is measured during the platinum oxidation in acidic media, with the second sense (S2) of VIONIC powered by INTELLO. Since dissolved Pt in solution could bias the results, it is important to be able to monitor the potential of the counter electrode.
- AN-SEC-003UV-Vis spectroelectrochemical cell for conventional electrodes
The development of a novel reflection cell for conventional electrodes facilitates the performance of spectroelectrochemical measurements. This device allows researchers to work in aqueous solutions as well as in organic media due to its chemical resistance.
- AB-064Platinization of platinum electrodes and conductivity measuring cells
It is a comparatively easy matter to coat platinum electrodes with platinum black by electrolytic deposition of the metal from a platinizing solution.
- AN-I-035Sodium content in food using an ion-selective electrode
Excess sodium intake increases the risk of health issues. Ion-selective electrodes (ISEs) offer a fast, accurate, and cost-effective method for measuring sodium in food.
- AB-134Determination of potassium with an ion-selective electrode
Potassium is one of the most common elements and can be found in many different minerals and other potassium compounds. It is of importance for humans, animals and plants as it is an essential mineral nutrient and involved in many cellular functions like cell metabolism and cell growth. For these reasons, it is important to be able to declare the potassium content of food or soil to reduce problems that may arise by a potassium deficiency or extensive consumption.This bulletin describes an alternative to flame photometric method using an ion selective electrode and direct measurement or standard addition technique. Several potassium determinations in different matrices using the combined potassium ion-selective electrode (ISE) are presented here. Additionally, general hints, tips and tricks for best measurement practice are given.
- AN-RA-002The carbon battle characterization of screen-printed carbon electrodes with SPELEC RAMAN
Carbon materials are a remarkable choice as electrode surfaces. They are not only cost-effective and chemically inert, but also have a low background current and a wide potential window. Physical and chemical properties of new carbon nanomaterials depend mainly on their structure, so their characterization is essential to choose the right material for different applications.Raman spectroscopy is a very attractive technique for this purpose, effortlessly distinguishing information about the bond structure of carbon materials, and, therefore, about their possible properties. DropSens screen-printed electrodes (SPEs) are low-cost, disposable devices, available with working electrodes fabricated in several carbon materials. This Application Note describes how their properties can be studied by Raman spectroscopy.
- AB-226Determination of arsenic by stripping voltammetry at the rotating gold electrode
This Bulletin describes the determination of arsenic by anodic stripping voltammetry (ASV) at the rotating gold electrode. A determination limit of 0.5 μg/L can be achieved with 10 mL sample solution. A differentiation between the As(III) concentration and the total arsenic concentration can be made by appropriate selection of the deposition potential. The analyses are performed with a special gold electrode whose active surface is located laterally; c(HCl) = 5 mol/L is used as supporting electrolyte. For the determination of the total arsenic content, As(III) and As(V) are reduced at -1200 mV by nascent hydrogen to As0, which is preconcentrated on the electrode surface. If the deposition is carried out at -200 mV then only As(III) is reduced; this allows the differentiation between total arsenic and As(III). During the subsequent voltammetric determination the preconcentrated As0 is again oxidized to As(III).
- AN-V-231Cadmium and lead in drinking water with screen-printed carbon electrodes
The provisional guideline values in the World Health Organization’s (WHO) «Guidelines for Drinking-water Quality» are set to 3 µg/L for cadmium and 10 µg/L for lead. The anodic stripping voltammetry (ASV) technique performed on the ex-situ mercury film modified Metrohm DropSens screen-printed electrode (SPE) can be used to simultaneously detect concentrations as low as 0.3 µg/L for both elements. This is suitable to monitor the WHO guideline values. The main advantage of this method lies in the innovative and cost-effective screen-printed electrode.
- AN-V-178Copper in seawater with the Mercury Film Electrode (MFE)
The concentration of Cu in seawater is determined by anodic stripping voltammetry (ASV) in acetate buffer on a mercury film electrode (MFE). Gallium is added to overcome zinc interferences.
- AN-T-120Automatic manganese determination in aqueous solution using the ion-selective copper electrode (Cu ISE)
Manganese in aqueous solution can be determined using back titration in alkali solution. The ion-selective copper electrode is used here as the indicator electrode.
- AN-T-122Automatic thallium determination in aqueous solution using the ion-selective copper electrode (Cu ISE)
Thallium in aqueous solution can be determined using back titration in a weak acidic solution. The ion-selective copper electrode is used here as the indicator electrode.
- AN-RA-003In situ, fast and sensitive: Electrochemical SERS with screen-printed electrodes
Substrates for surface-enhanced Raman spectroscopy (SERS) are typically fabricated with complex (micro/nano)structures of noble metals, enabling trace level detection of analytes. Due to the high costs and reactivity of these SERS substrates, they often have a limited shelf life. Development of new substrate materials which minimize these issues yet maintain the same performance standards is a constant concern.Screen-printed electrodes can be easily fabricated using different metallic materials with the well-established screen-printing method, leading to mass production of versatile, cost-effective, and disposable devices. In this Application Note, the feasibility of using readily-available screen-printed metal electrodes as suitable substrates for the fast and sensitive detection of different chemical species by in situ electrochemical SERS (EC-SERS) is shown.
- AN-T-117Automatic determination of aluminum and magnesium mixtures with ion-selective copper electrode (Cu ISE)
Aluminum and magnesium ion mixtures are analyzed using back-titration at different pH values. The ion-selective copper electrode is used here as the indicator electrode. First, the aluminum is determined in acidic solution and then the magnesium in alkali solution.
- WP-022In situ SERS effect with screen-printed silver electrodes
In this work, time resolved Raman spectroelectrochemistry measurements with screen printed electrodes are shown. The instrument used combines in a totally integrated box: a 785 nm laser source, a high resolution Raman spectrometer and a bipotentiostat/galvanostat. Experiments are controlled with an excellent spectroelectrochemical software which allows real time data collection and useful data treatment.
- AB-241Determination of cadmium and lead by anodic stripping voltammetry at a mercury film electrode
This Application Bulletin describes the determination of cadmium and lead at a mercury film electrode (MFE) by anodic stripping voltammetry (ASV). The mercury film is plated ex situ on a glassy carbon electrode and can be used for up to one day. With a deposition time of 30 s, the limit of detection is ß(Cd2+) = 0.02 µg/L and ß(Pb2+) = 0.05 µg/L. The linear working range for both elements goes up to approx. 50 μg/L using the same deposition time.
- AN-V-232Nickel and cobalt in drinking water with screen-printed carbon electrodes
EU legislation specifies 20 µg/L as the limit value for nickel in drinking water. The current provisional guideline value for Ni in the World Health Organization’s «Guidelines for Drinking-water Quality» is set to a maximum concentration of 70 µg/L. The adsorptive stripping voltammetry (AdSV) technique performed on the ex-situ bismuth film modified Metrohm DropSens 11L screen-printed electrode (SPE) can be used to simultaneously detect concentrations as low as 0.4 µg/L for nickel and 0.2 µg/L for cobalt with a 30 s deposition time.The disposable, maintenance-free sensor can be used conventionally in the laboratory with the 884 Professional VA, or alternatively in the field with the 946 Portable VA Analyzer. This method is best suited for manual systems.
- AN-T-123Automatic zirconium determination in aqueous solution with ion-selective copper electrode (Cu ISE)
Zirconium can be analyzed quickly and easily in slightly acidic solutions with back titration. The ion-selective copper electrode is used in this Application Note to determine zirconium in aqueous solution.
- AN-T-121Automatic indium determination in aqueous solution using the ion-selective copper electrode (Cu ISE)
This application note shows the use of an ion-selective copper electrode to measure the indium concentration in an aqueous solution.
- AB-254Determination of zinc, cadmium and lead by anodic stripping voltammetry at a mercury film electrode
This Application Bulletin describes the determination of zinc at a mercury film electrode (MFE). Zinc can also be determined simultaneously with cadmium and lead. The determination of copper at the MFE is not possible. The mercury film is plated ex-situ on a glassy carbon electrode and can be used for half a day up to one day.Zinc can be determined at the mercury film electrode by anodic stripping voltammetry (ASV). The presence of copper, which is naturally present in many samples, affects the determination of zinc due to the formation of an intermetallic compound. As a result the determined concentrations of zinc are too low. The addition of gallium can eliminate the interference to a certain extent since the intermetallic complex of gallium and copper is more stable than the complex of zinc and copper.With a deposition time of 10 s, the limit of detection is β(Zn2+) = 0.15 μg/L. The linear working range goes up to approx. 300 μg/L.With the deposition time of 10 s the method is suitable for samples between 10 μg/L and 150 μg/L Zn content. For samples with lower concentrations the results are more reliable if the deposition time is increased to e.g. 30 s. Samples with higher concentrations have to be diluted.
- AN-EC-025Study of the hydrogen region at platinum electrodes with linear scan cyclic voltammetry
The study of the electrochemical behavior of platinum in acidic media is of crucial importance in fundamental electrochemistry and electrocatalysis. Most electrocatalytic processes occurring at Pt electrodes are highly sensitive to the structure of the platinum surface. Cyclic voltammetry (CV) is a widely used rapid measurement technique that provides both a qualitative and quantitative fingerprint of platinum surfaces. A comparison of results given by linear and staircase CVs is presented in this Application Note.
- AN-T-116Automatic sulfate determination in aqueous solution using a combined ion-selective calcium electrode (Ca ISE)
This Application Note describes automatic sulfate determination using a combined ion-selective calcium electrode. Sulfate is precipitated with an excess of barium chloride solution. Excess barium is subsequently back-titrated with a standard EGTA solution.
- AB-133Determination of ammonia with the ion-selective electrode – Tips and tricks for a reliable determination according to common standards
Although the known photometric methods for the determination of ammonia/ammonium are accurate, they require a considerable amount of time (Nessler method 30 min, indophenol method 90 min reaction time). A further disadvantage of these methods is that only clear solutions can be measured. Opaque solutions must first be clarified by time-consuming procedures. These problems do not exist with the ion-selective ammonia electrode. Measurements can be easily performed in waste water, liquid fertilizer, and urine as well as in soil extracts. Especially for fresh water and waste water samples several standards, such as ISO 6778, EPA 350.2, EPA 305.3 and ASTM D1426, describe the analysis of ammonium by ion measurement. In this Application Bulletin, the determination according to these standards is described besides the determination of other samples as well as some general tips and tricks on how to handle the ammonia ion selective electrode. Determination of ammonia in ammonium salts, of the nitric acid content in nitrates, and of the nitrogen content of organic compounds with the ion-selective ammonia electrode is based on the principle that the ammonium ion is released as ammonia gas upon addition of excess caustic soda:NH4+ + OH- = NH3 + H2OThe outer membrane of the electrode allows the ammonia to diffuse through. The change in the pH value of the inner electrolyte solution is monitored by a combined glass electrode. If the substance to be measured is not present in the form of an ammonium salt, it must first be converted into one. Organic nitrogen compounds, especially amino compounds are digested according to Kjeldahl by heating with concentrated sulfuric acid. The carbon is oxidized to carbon dioxide in the process while the organic nitrogen is transformed quantitatively into ammonium sulfate.
- AN-T-171Redox titration of vitamin C in milk powder using the double Au-ring electrode
Vitamin C is an important antioxidant included in milk powder. The double Auring electrode provides an excellent titration curve when using 2,6-dichlorophenolindophenol (DPIP) as titrant and is easy to clean.With the OMNIS system, a fast and accurate determination of vitamin C in milk powder by a bi-voltametric titration is realized.
- AB-096Determination of mercury at the rotating gold electrode by anodic stripping voltammetry
This Application Bulletin describes the determination of mercury by anodic stripping voltammetry (ASV) at the rotating gold electrode. With a deposition time of 90 s, the calibration curve is linear from 0.4 to 15 μg/L; the limit of quantification is 0.4 μg/L.The method has primarily been drawn up for investigating water samples. After appropriate digestion, the determination of mercury is possible even in samples with a high load of organic substances (wastewater, food and semi-luxuries, biological fluids, pharmaceuticals).
- AB-230Potentiometric determination of nonionic surfactants based on polyoxyethylene adducts with the NIO electrode
The titrimetric determination of nonionic surfactants on the basis of polyoxyethylene adducts (POE adducts) is described in the Bulletin. The basis for the determination is the transfer of the nonionic surfactant into a pseudo-cation compound and its precipitation titration with sodium tetraphenylborate (Na-TPB). The NIO electrode is used for the indication of the potentiometric titration. This Bulletin describes determinations in raw products, formulations and wastewater and draws attention to special features, possibilities, limits and disruptions.
- AB-438Determination of cadmium and lead in water samples by anodic stripping voltammetry with a Bi drop electrode
Heavy metals, particularly cadmium and lead, are known to be highly toxic to humans. Therefore, controlling the cadmium and lead content in drinking water is of utmost importance. In many countries, the limit in drinking water for cadmium is between 3–5 µg/L, and for lead it is between 5–15 µg/L. These trace concentrations can reliably be determined with the method described in this Application Bulletin. The determination is carried out by anodic stripping voltammetry (ASV) using the non-toxic Bi drop electrode in a slightly acidic electrolyte.
- AN-EC-034Ion-selective electrodes based on screen-printed technology
Advances in polymeric membranes and screen-printed technologies have enabled miniaturized, portable potentiometric sensors ideal for point-of-care analysis.
- AN-V-061Iron speciation in water with the Multi-Mode Electrode pro
Accurate determination of Fe(II) and Fe(III) in water is crucial for many industries. Cathodic sweeping voltammetry (CSV) offers a robust, cost-effective solution.
- AN-V-237Lead stabilizer in an electroless Ni plating bath
Electroless nickel plating ensures low-cost wear and corrosion resistance. Monitoring lead stabilizer levels in Ni plating baths is possible with the Bi drop electrode.
- AN-RA-010SERS detection of pesticides using screen-printed electrodes
EC-SERS enhances Raman sensitivity using electrochemically activated gold SPEs, enabling rapid, simplified pesticide detection without complex prep or instrumentation.
- AN-I-036Sodium content in water using an ion-selective electrode
Groundwater contains many minerals, but can be contaminated by sodium-rich leachate from landfills. Accurate Na determination in water is possible following AOAC 976.25 using the Na-ISE.
- AN-EC-006Displacement Deposition of Platinum on Gold Electrodes
This document describes a very simple procedure that can be used to produce small deposits of platinum on a goldsubstrate. This simple procedure is based on an electrochemical process known as displacement deposition, during which the deposition of a noble metal occurs by the oxidation of a precursor metal adlayer deposited on the substrate, at open circuit potential (OCP).
- AN-COR-019Determining the corrosion rate with INTELLO
Tafel analysis is an important electrochemical technique used to understand reaction kinetics. By studying the Tafel slope, it reveals the rate-determining steps in electrode reactions, aiding fields like corrosion and fuel cell research. This method helps industries optimize processes and improve device performance by tailoring materials and conditions for greater efficiency.
- AB-121Determination of nitrate with the ion-selective electrode
It has been known for years that consuming too much nitrates from foodstuffs can result in cyanosis, particularly for small children and susceptible adults. According to the WHO standard, the hazard level lies at a mass concentration c(NO3-) ≥ 50 mg/L. However, more recent studies have shown that when nitrate concentrations in the human body are too high, they can (via nitrite) result in the formation of carcinogenic and even more hazardous nitrosamines.Known photometric methods for the determination of the nitrate anion are time-consuming and prone to a wide range of interferences. With nitrate analysis continually increasing in importance, the demand for a selective, rapid, and relatively accurate method has also increased. Such a method is described in this Application Bulletin. The Appendix contains a cselection of application examples where nitrate concentrations have been determined in water samples, soil extracts, fertilizers, vegetables, and beverages.
- AN-H-143Sulfuric acid and tartaric acid in tartaric sulfuric anodizing bath – Rapid, sequential determination using a thermometric sensor (thermometric titration)
Tartaric Sulfuric Anodizing (TSA) is an established technique for corrosion protection in the aerospace industry. It is an alternative to the environmentally harmful chromic anodizing process. As such, a method to monitor the levels of sulfuric acid and tartaric acid in TSA plating baths is required. Potentiometric titration methods have been developed, and are widely used across the industry. Their disadvantage is that two titrations with different electrodes and solvents are required.In this Application Note, an alternative method is presented, where the concentration of both acids is determined in sequence using a thermometric sensor. Compared to potentiometric titration, thermometric titration is faster and more convenient (no sensor maintenance required). On a fully automated system, the determination of both parameters takes about 7 minutes.
- AN-V-240Determination of total iodine in thyroid tablets with polarography
Accurate iodine determination in thyroid tablets, ensuring treatment efficacy, is achieved using the 884 Professional VA and Multi-Mode Electrode pro per USP guidelines.
- 8.000.6097TP screen printed ethanol sensor (EN)
Non-enzymatic ethanol sensor based on a nanostructured disposable screen-printed electrode.
- AN-T-188Iron content in iron ore
The total iron content in iron ore plays a central economic role for mining companies. The higher the iron content in the ore, the more profitable the mining operation. Therefore, a fast and accurate analysis is important to determine the most profitable areas to work.The iron ore is dissolved in hydrochloric acid at 80 °C. Afterwards, the iron is quickly and accurately determined by potentiometric titration using the Pt-ring electrode and potassium dichromate as titrant.
- AN-V-222Iron determination in drinking water
The presence of iron in drinking water can lead to an unpleasant taste, stains, or even growth of «iron bacteria» that can clog plumbing and cause an offensive odor. Over a longer period, the formation of insoluble iron deposits is problematic in many industrial and agricultural applications. To avoid these problems, the U.S. Environmental Protection Agency (EPA) defines the Secondary Maximum Contaminant Level (SMCL) for water treatment and processing plants as 0.3 mg/L Fe in drinking water.The voltammetric determination of the iron triethanolamine complex on the non-toxic Bi drop electrode allows both the detection at very low levels (limit of detection of 0.005 mg/L) and measurements in a wide range of concentrations up to 0.5 mg/L.
- 8.000.6093Determination of arsenic in water with the gold electrode (scTRACE Gold)
Because of its toxicity, the World Health Organization recommends a maximum arsenic content in drinking water of 10 μg/L. Anodic stripping voltammetry with the scTRACE Gold offers a straightforward, highly affordable alternative to spectroscopic determination.
- AB-439Voltammetric determination of iron in water samples with a Bi drop electrode
Iron is an essential element in the human diet and is found in many natural and treated waters. Therefore, the World Health Organization (WHO) does not issue a health-based guideline value for iron. Higher concentrations of iron in surface waters can indicate the presence of industrial effluents or outflow from other operations and sources of pollution. Because of this, precise, rapid, and accurate iron determination at low concentrations in environmental and industrial samples is of great importance. This can be achieved with the method described in this Application Bulletin.
- AN-I-020Potassium in liquid and solid NPK fertilizers – Fast and inexpensive determination using the ionselective electrode
NPK fertilizers are mainly comprised of three primary nutrients required for a healthy plant growth (nitrogen, phosphorous, potassium). They are available as liquid, or granular form, whereof the last is the most common used one. Knowing the quality and content of a fertilizer allows an optimal utilization for a planned culture and optimizing the amount of used fertilizer. This helps to reduce costs and to improve plant growth and with it, a better harvest follows.To assess potassium, several methods like flame photometry, titration, or ion measurement can be used. In this work, the potassium content is measured by standard addition which is a fast, inexpensive, and easy to use method.
- AB-440Determination of nickel and cobalt in water samples by adsorptive stripping voltammetry with a Bi drop electrode
Cobalt is an essential element for humans because it is a component of vitamin B12. While small overdoses of cobalt compounds are only slightly toxic to humans, larger doses from 25–30 mg per day may lead to skin, lung, and stomach diseases, as well as liver, heart, and kidney damage, and even cancerous growths. The same is valid for nickel, which can lead to inflammation at higher concentrations. Drinking a large amount of water containing nickel can cause discomfort and nausea. In the EU the legislation specifies 0.02 mg/L as the limit value for the nickel concentration in drinking water. This concentration can be reliably determined with the method described in this Application Bulletin.
- AN-BAT-011Determination of the Through-Plane Tortuosity of Battery Electrodes by EIS in a symmetric Lithium-iron-phosphate cell
In this application note, we demonstrate how to determine the through-plane tortuosity τ of a commercial lithium ion battery cathode material with known porosity and coating thickness, based on the electrochemical impedance spectroscopy (EIS) method.
- AN-T-065Astemizole in raw products
Determination of the antihistamine astemizole in raw products by nonaqueous potentiometric titration with perchloric acid using separate electrodes.
- AN-H-141Acid number in crude oil and gas oil according to ASTM D8045
Thermometric titration can determine the total acid number (TAN) of various crude oil products according to ASTM D8045 without requiring any sensor maintenance.
- AB-269Potentiometric determination of ionic surfactant through two-phase titration with the Surfactrode
On the basis of a multitude of practical examples, this Bulletin describes the potentiometric two-phase titration of ionic surfactants in raw materials and many other formulations.Two surfactant electrodes – the Surfactrode Resistant and the Surfactrode Refill – make it possible to perform this type of surfactant titration, analogous to the classic "Epton titration", with a high degree of automation. The achieved results correlate very well with those of Epton titration. The toxic, carcinogenic and environmentally hazardous chloroform can be replaced by other solvents such as methyl iosbutyl ketone or n-hexane.
- 8.000.6110Fluoride in OTC Products by Ion Chromatography
Fluoride is commonly used in dental products to help prevent tooth decay. When fluoride is present in high concentrations, these products are regulated by 21 CFR 355. Three fluoride compounds used in over the counter (OTC) anti‐cavity dental products are sodium fluoride, stannous fluoride and sodium monofluorophosphate (MFP). The assay of fluoride in these active ingredients and finished formulations are determined by manual titration, or by ion‐selective electrodes. As a part of USP’s global monograph modernization initiative, an alternative selective and sensitive method has been developed and validated – ion chromatography (IC). The proposed IC method can also be used for the identification test as an alternative to the wet chemistry method.
- 8.000.6113Determination of Trace Level Lead (Pb) in Drinking Water Using a Mercury-Free Electrode and a Portable InstrumentAccording to the Requirements of USEPA Lead and Copper Rule
Lead is known to be highly toxic, and lead salts are easily resorbed by humans. Cases of chronic lead poisoning caused by lead metal used in the water piping system are well known. Therefore, the control of drinking water for lead content is of utmost importance. The Lead and Copper Rule (LCR) published by the USEPA (United States Environmental Protection Agency) states an action limit of 15 μg/L lead for drinking water. Using a portable voltammetric instrument, lead can be determined in these concentrations directly at the point of sampling.
- AN-V-057Thiomersal in eye drops
Thiomersal (also called thimerosal) is a mercury containing organic molecule that has been widely used as preservative for vaccines and eye drops. It is very effective, even in very low concentrations, against a wide range of microorganisms and viruses. To reduce the risk for consumers the maximum concentration of mercury in the products is limited by the authorities. Polarography or voltammetry can be used to accurately determine the concentration of thiomersal in vaccines or other cosmetic and pharmaceutical solutions (such as eye drops). The method is simple to perform, specific, and free of interferences.
- AN-V-195Iodate in electroless nickel baths
Electroless nickel plating is an important and well established process in the surface finishing industry. In the past, the addition of small amounts of lead has widely been used to stabilize the plating bath. With the increasing number of restrictions in recent years on the use of lead in consumber products, particularly electronics, alternative stabilizers were developed and introduced. One of the stabilizers used as lead replacement is iodate. It can be used as a single additive or in combination with bismuth or antimony. This method allows the determination of iodate directly in the plating bath sample by polarography. The method is simple and fast, however, sensitive and robust.
- AN-V-196Antimony and bismuth in electroless nickel baths
Electroless nickel plating is an important and well established process in the surface finishing industry. In the past the addition of small amounts of lead has widely been used to stabilize the plating bath. With the increasing number of restrictions in recent years on the use of lead in consumber products, particularly electronics, alternative stabilizers were developed and introduced. Two of the stabilizers used as lead replacement are antimony and bismuth. They can be used as a single additive or in combination with each other or iodate. This method allows the determination of antimony and bismuth directly in the plating bath sample by anodic stripping voltammetry (ASV). The method is simple and fast, however sensitive and robust
- AB-235Potentiometric titration of calcium (magnesium) in dairy products
This Bulletin describes a simple method for the determination of the calcium content in dairy products. The use of CuEGTA and the ion-selective copper electrode (Cu ISE) as indicator electrode allows the determination to be performed without time-consuming sample preparation. If the complexing agent EDTA is used as titrant instead of EGTA, the sum of calcium and magnesium is obtained. The magnesium content can then be calculated from the difference between the results of the two titrations.
- AN-V-203Determination of copper in electrolyte solutions for production of CIGS solar cells
This Application Note describes the polarograhic determination of copper in electroplating baths used in the production of thin-film copper indium gallium diselenide solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate.Copper analysis is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.
- AN-V-204Determination of indium in electrolyte solutions for production of CIGS solar cells
This Application Note describes the polarographic determination of indium in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on the molybdenum-coated substrate. Indium analysis is carried out after dilution of the bath sample with sulfuric acid as supporting electrolyte.
- AN-V-206Determination of selenite in electrolyte solutions for production of CIGS solar cells
This Application Note describes the polarographic determination of selenite in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate. Selenite analysis is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.
- AN-V-205Determination of gallium in electrolyte solutions for production of CIGS solar cells
This Application Note describes the determination of gallium in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate. Gallium analysis using anodic stripping voltammetry (ASV) is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.
- AB-086Measuring the pH value of dairy products
This Bulletin describes methods for measuring the pH value of dairy products. Particular attention has been paid to the handling, maintenance, and storage of the pH electrodes.
- AN-V-190Mercury in polymer materials as part of electrotechnical products
The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulatedheavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC62321 the determination of mercury in polymer materials can be carried out by anodic stripping voltammetry (ASV)at a gold rotating disk electrode (Au-RDE).
- AN-V-187Mercury in electronic components as part of electrotechnical products
The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulated heavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC 62321 the determination of mercury in electronic components can be carried out by anodic stripping voltammetry (ASV) at a gold rotating disk electrode (Au-RDE).
- AN-V-193Mercury in metallic materials as part of electrotechnical products
The EU directive on «Restriction of Hazardous Substances» (RoHS) requires the testing of four regulated heavy metals (Pb, Hg, Cd, Cr(VI)) in electrotechnical products. After sample preparation according to IEC 62321 the determination of mercury in metallic materials can be carried out by anodic stripping voltammetry (ASV) at a gold rotating disk electrode (Au-RDE).
- AN-COR-003Measurement of polarization resistance
Polarization resistance (Rp) can quantify the corrosion resistance of metals as an alternative to Tafel analysis. Its methodology and practical use as described in ASTM G59 are discussed.
- AN-V-220Remaining Useful Life of lubricants
Testing of in-service lubricating oils for their remaining antioxidant content is critical for capital equipment uptime as well as reducing running costs and repair expenses. Test methodologies such as RPVOT (rotating pressure vessel oxidation test) are time consuming and expensive to perform. Remaining Useful Life is a proven voltammetric method for testing the remaining active antioxidant content in minutes. Depending on the electrolyte, aromatic amine and phenolic antioxidants or hindered phenolic antioxidants can be determined.For the first time, a fully automated system is demonstrated, showing dramatically improved repeatability of data for confidence in reporting. Operator time is saved during sample preparation and irreproducible manual interpretation is eliminated via completely autonomous software processing. The user adds the sample into the vials, then the determination process of the sample series (including sample preparation and result calculations) is carried out automatically. The system is based on methods ASTM D6810, ASTM D6971, ASTM D7527, and ASTM D7590.
- AB-140Titrimetric sulfate determination
This Bulletin describes three potentiometric, one photometric, one thermometric and one conductometric titration method for sulfate determination. The question of which indication method is the most suitable depends primarily on the sample matrix.Method 1: Precipitation as barium sulfate and back titration of the Ba2+ surplus with EGTA. Use of the ion-selective calcium electrode as indicator electrode.Method 2: As with Method 1, although with the electrode combination tungsten/platinum.Method 3: Precipitation titration in semi-aqueous solution with lead nitrate in accordance with the European Pharmacopoeia using the ion-selective lead electrode as indicator electrode.Method 4: Photometric titration with lead nitrate, dithizone indicator and the Optrode 610 nm, particularly suitable for low concentrations (up to 5 mg SO42- in the sample solution).Method 5: Thermometric precipitation titration with Ba2+ in aqueous solution, particularly suitable for fertilizers.Method 6: Conductometric titration with barium acetate in accordance with DIN 53127
- AB-101Complexometric titrations with the Cu ISE
This Bulletin describes the complexometric potentiometric titration of metal ions. An ion-selective copper electrode is used to indicate the endpoint of the titration. Since this electrode does not respond directly to complexing agents, the corresponding Cu complex is added to the solution. With the described electrode, it is possible to determine water hardness and to analyze metal concentrations in electroplating baths, metal salts, minerals, and ores. The following metal ions have been determined: Al3+, Ba2+, Bi3+, Ca2+, Co2+, Fe3+, Mg2+, Ni2+, Pb2+, Sr2+, and Zn2+.
- AN-V-019Lead in a nickel plating bath
Lead is commonly used as stabilizer in electroless nickel plating processes. The regular and precise determination of the electrochemically active Pb(II) concentration is essential to keep the plating process running optimally under stable conditions. Differential pulse anodic stripping voltammetry can be used to determine the active lead content after dilution. The voltammetric determination has been established as a straightforward, sensitive, selective, and interference-free method for this application.
- AB-268Potentiometric titration of surfactants and pharmaceuticals – an overview
The present Bulletin offers an overview of the multitude of surfactants and pharmaceuticals that can be determined with potentiometric titration. Metrohm provides five different surfactant electrodes for indicating the titration endpoint: the Ionic Surfactant, the High Sense, the Surfactrode Resistant, the Surfactrode Refill and the NIO Surfactant electrode. The manufacture of the respective titrants and their titer determination are described in detail. In addition to this, the Bulletin contains a tabular overview of more than 170 proven applications from the area of surfactant and pharmaceutical analysis. This guideline leads you reliably to your destination: At a glance you can see from the table which surfactant electrode and which titrant are optimally suitable for your product.
- AB-181Automatic potentiometric titration of aluminum and magnesium in the same solution
Mixtures of aluminum and magnesium ions can be analyzed automatically using potentiometric titration. The excess DCTA is back-titrated with copper(II) sulfate solution after the addition of 1,2-diaminocyclohexanetetraacetic acid (DCTA) and complex formation. The ion-selective copper electrode is used here as the indicator electrode. First, the aluminum is determined in acidic solution and then the magnesium in alkali solution.
- AN-V-235Cadmium in chocolate
The toxic element cadmium (Cd) can be found in elevated concentrations with high bioavailability in some soils. Under such conditions, cacao trees can accumulate cadmium in the beans, which are then processed into cocoa. Chocolate produced from the affected beans will contain elevated cadmium levels. Typical limit values in the European Union are between 100 µg/kg and 800 µg/kg (EU Commission Regulation 1881/2006) depending on the cocoa content of the chocolate.Anodic stripping voltammetry (ASV) can be used to accurately determine trace quantities of cadmium in chocolate down to approximately 10 µg/kg. The method is simple to perform, specific, and free of interferences. Prior to determination the samples are ashed in a furnace at 450 °C.
- AN-V-127Fe(II) in iron sucrose injection (USP)
Iron sucrose injection is a dark brown liquid which contains sucrose and iron(III) hydroxide in an aqueous solution, commonly used for the treatment of iron deficiency anemia. As a medical product, iron sucrose is subject to strict controls. Among other tests, the U.S. Pharmacopeia (USP) requires to monitor the limit of Fe(II) in the iron sucrose injection solution by polarography. The benefit of polarography is that Fe(II) and Fe(III) show signals at different potentials, and therefore an easier determination of Fe(II) without a previous separation of the two oxidation states is possible. The 884 Professional VA together with the viva software allows a straightforward determination of the Fe(II) content of iron sucrose injection solution following the requirements of the USP. The Fe(II) content is automatically calculated and stored in a database together with all relevant determination and calculation parameters.
- AN-T-070Determination of calcium pantothenate
Determination of calcium pantothenate by nonaqueous potentiometric titration with perchloric acid using separate electrodes.
- AN-V-199Voltammetric determination of gold(I) in gold plating baths
Controlling Au(I) levels in gold plating baths is required for high quality. Voltammetric analysis with the Multi-Mode Electrode Pro is an efficient solution.
- AN-T-014Chlorhexidine in a wash lotion
Determination of chlorhexidine in wash lotion by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.
- AN-T-018Determination of total penicillin content
Determination of total penicillin content through potentiometric titration with Hg(II) using the combined Au electrode. Keyword: Antibiotics
- AN-T-012Cationic surfactants in hair conditioner
Determination of cationic surfactants in hair conditioner by potentiometric titration with dioctyl sodium sulfosuccinate using the «Ionic Surfactant electrode.
- AN-T-023Hydroxide and carbonate in alkaline plating baths for cadmium, copper, lead, or zinc
Determination of hydroxide and carbonate in alkaline plating baths by potentiometric titration with HCl using the combined glass electrode.
- AN-T-010Anionic surfactants in shower lotions and shampoos
Determination of anionic surfactants in shower lotions and shampoos by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.
- AN-T-011Anionic surfactants in a nickel plating bath
Determination of anionic surfactants in a nickel plating bath by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.
- AN-T-017Determination of ampicillin content
Determination of ampicillin in raw and pure products through potentiometric titration with Hg(II) using the combined Au electrode. Keyword: Antibiotics
- AN-T-020Cr(VI) and Cr(III) in chromium baths
Determination of Cr(VI) and Cr(III) in chromium baths by iodometric potentiometric titration with thiosulfate using the combined Pt electrode.
- AN-T-048Anionic surfactants in a shower oil by potentiometric two-phase titration
Determination of anionic surfactants in shower oil by potentiometric two-phase titration with TEGO®trant A100 using the «Surfactrode Resistant» electrode.
- AN-T-108Fully automated determination of zinc(II) in aqueous solution
This Application Note describes the fully automated complexometric determination of zinc(II) in aqueous solutions with a copper ion-selective electrode.
- AN-T-151Titration of ketoconazole in accordance with Ph. Eur.
This Application Note describes the nonaqueous acid-base titration of ketoconazole in accordance with the European Pharmacopoeia. The Solvotrode easyClean was used as the electrode.
- WP-063Recommendations for converting a manual titration procedure into an automated titration procedure
This white paper summarizes the steps involved in converting an existing manual titration procedure to semi-automated or automated titration procedures. It discusses topics such as selecting the right electrode and titration mode. For a better understanding, the discussion topics are illustrated with three examples.
- AN-I-001Fluoride content in toothpaste
Fluoride protects dental enamel and is an important trace element in toothpaste. A rapid and precise determination is made via standard addition with the help of an ion-selective fluoride electrode (F-ISE).
- AB-137Coulometric water content determination according to Karl Fischer
This Application Bulletin gives an overview of the coulometric water content determination according to Karl Fischer.Amongst others, it describes the handling of electrodes, samples, and water standards. The described procedures and parameters comply with the ASTM E1064.
- AB-036Half wave potentials of metal ions for the determination by polarography
In the following tables, the half-wave potentials or peak potentials of 90 metal ions are listed. The half-wave potentials (listed in volts) are measured at the dropping mercury electrode (DME) at 25 °C unless indicated otherwise.
- AB-077Volumetric water content determination according to Karl Fischer – Tips and tricks for volumetric Karl Fischer titration
This Application Bulletin gives an overview of the volumetric water content determination according to Karl Fischer. Amongst others, it describes the handling of electrodes, samples, and water standards. The described procedures and parameters comply with the ASTM E203.
- AB-132Polarographic determination of molybdenum in strongly ferruginous materials
A method is described in this Bulletin that allows molybdenum to be determined in steel and other materials containing a high iron concentration. Mo(VI) is determined at the dropping mercury electrode by catalytic polarography. The determination limit is approx. 10 μg/L Mo(VI).
- AN-T-168EDTA in liquid hand soap in accordance with ASTM D1767
Complexing agents such as EDTA are used in soaps and other detergents in order to remove unwanted metal ions and to lower water hardness. The EDTA content in soaps and detergents can be determined using potentiometric titration with copper sulfate as titrant and the Cu-ISE as electrode.
- AN-P-080Content of gentamicin according to USP applying pulsed amperometric detection
Gentamicin is an aminoglycoside antibiotic and is composed of a number of related gentamicins. It is applied for several types of infections. For the determination of the major components, USP asks for chromatographic separation with pulsed amperometric detection using a gold working electrode. A post-column addition of NaOH is performed prior to the detection.
- AN-EIS-007EIS Data fitting – How to obtain good starting values of equivalent circuit elements
Electrochemical impedance spectroscopy (EIS) is a powerful technique which provides information about the processes occurring at the electrode-electrolyte interface. The data collected with EIS are modeled with a suitable electrical equivalent circuit. The fitting procedure will change the values of the parameters until the mathematical function matches the experimental data within a certain margin of error. In this Application Note, some suggestions are given in order to get acceptable initial parameters and to perform an accurate fitting.
- AN-V-174Arsenic in zinc plant electrolyte
The concentration of As(total) in zinc plant electrolyte is determined by anodic stripping voltammetry (ASV) on a lateral gold electrode in HCl electrolyte. Due to the high excess of zinc in the sample the deposition potential has to be adapted. A second potential approx. 100 mV more negative than the arsenic signal has to be applied to selectively oxidize interfering antimony. For sample preparation the sample was passed through a cation exchange column to reduce the concentration of zinc in the measuring solution.
- WP-062Overcoming difficulties in ion measurement: Tips for standard addition and direct measurement
Ion measurement can be conducted in several different ways, e.g., ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP-OES), or atom absorption spectroscopy (AAS). Each of these are well-established, widely used methods in analytical laboratories. However, the initial costs are relatively high. In contrast, ion measurement by the use of an ion-selective electrode (ISE) is a promising alternative to these costly techniques. This White Paper explains the challenges which may be encountered when applying standard addition or direct measurement, and how to overcome them in order for analysts to gain more confidence with this type of analysis.
- 8.000.6023Determination of anionic and cationic surfactants by potentiometric two-phase titration
Compared to the classical Epton titration, potentiometrically indicated two-phase titrations using organic-solvent-resistant Surfactrodes can be easily automated and require no toxic and environmentally hazardous chloroform. Even challenging matrices such as fats and oils in bath oils and hair conditioners or strong oxidizing agents in washing powder and industrial cleaners do not interfere with the titration of the ionic surfactants. Results obtained show excellent agreement to those of the Epton titration. Irrespective of the matrix, relative standard deviations of threefold determinations are all below 2.1%. While the Surfactrode Resistant is mainly used for oil-containing formulations, the Surfactrode Refill is ideal for washing powders and soaps. Both electrodes excel by their ruggedness and allow the rapid and precise determination of anionic and cationic surfactants.
- AB-420Determination of suppressor with CVS using the calibration technique «smartDT» with dynamic addition volumes
The Application Bulletin describes the determination of suppressor in acid copper baths by smartDT. The determination of suppressor with dilution titration (DT) involves numerous additions with standard solution or sample to reach the evaluation ratio. Usually fixed, equidistant addition volumes are used. With smartDT, variable addition volumes are used that are dynamically calculated by the software. At the beginning, the volumes are bigger. Towards the evaluation ratio, the addition volume becomes smaller to guarantee a good accuracy of the result. The operator defines the first and the smallest addition volume to be used. All volumes in between are calculated by the software considering the progress of the determination. The time saving with smartDT compared to a classic DT with fixed addition volumes can be up to 40%. smartDT is suitable for nonlinear regression and quadratic regression as well as linear interpolation. It can be used for determination of suppressor in acid copper baths as well as in tin and tin-lead baths and works with 1, 2, and 3 mm Pt working electrodes. A 800 Dosino is required for the automatic addition of suppressor standard or sample. The method can also be used in fully automated systems.
- AB-317Determination of iron in the µg/L-range by polarography
This Application Bulletin describes two methods for the determination of iron at the Multi Mode Electrode.Method 1, the polarographic determination at the DME, is recommended for concentrations of β(Fe) > 200 μg/L. For this method the linear range is up to β(Fe) = 800 μg/L.For concentrations < 200 μg/LMethod 2, the voltammetric determination at the HMDE, is to be preferred. The detection limit for this method is β(Fe) = 2 μg/L, the limit of quantification is β(Fe) = 6 μg/L. The sensitivity of the method cannot be increased by deposition.Iron(II) and iron(III) have the same sensitivity for both methods.These methods have been elaborated for the determination of iron in water samples. For water samples with high calcium and magnesium concentrations such as, for example, seawater, a slightly modified electrolyte is used in order to prevent precipitation of the corresponding metal hydroxides. The methods can also be used for samples with organic loading (wastewater, beverages, biological fluids, pharmaceutical or crude oil products) after appropriate digestion.
- AN-BAT-013Simultaneous EIS measurements of a Li-ion battery cathode and anode
In battery research, electrochemical impedance spectroscopy (EIS) is a necessary tool to investigate the processes occurring at the electrodes. With a common three-electrode battery, EIS can be performed sequentially first at one electrode and then at the other electrode.
- AN-BAT-004Potentiostatic intermittent titration technique (PITT)
During charge and discharge of a Li-ion battery, lithium ions are transported from one electrode through the electrolyte to the other electrode. Knowing the chemical diffusion coefficient of electrode materials is crucial. The potentiostatic intermittent titration technique (PITT) is one of the most used techniques to retrieve insights on the diffusion coefficient of the electrode active materials.
- AN-H-140Titration of phosphoric, nitric, and acetic acid mixtures
Nitric acid, phosphoric acid, and acetic acid are easily determined in etching baths using thermometric titration (TET). Compared to potentiometric titration, TET is faster and more convenient. Analysis is complete in less than two minutes.
- AN-P-059Sulfide in wastewater with Metrosep A Supp 10 - 100/4.0 and amperometric detection
Ion chromatographic determination of sulfide in wastewater is performed using amperometric detection and an alkali eluent to ensure the stability of the sulfide. Measurements are performed in single-potential or direct current (DC) amperometric mode. It is the best-known and most sensitive amperometric measuring method and also provides, in addition to a high selectivity, a large selection of working electrodes.Sulfide determination is performed on a Metrosep A Supp 10 - 100/4.0 type column; a silver electrode is used as the working electrode.
- AN-V-179Iron in boiler feed water
The iron concentration in boiler feed water has to be monitored to ensure reliable and safe operation of the water-steam circuit. Various guidelines set limits for the maximum iron content.The concentration of total iron in boiler feed water can be determined with high sensitivity using adsorptive stripping voltammetry (AdSV) using 2,3- dihydroxynaphthalene (DHN) as complexing agent. Voltammetry is a viable, less sophisticated alternative to atomic absorption spectroscopy (AAS) or inductive couple plasma (ICP) for the determination of iron with only a moderate investment in hardware required and low running costs.
- AN-P-083Cyanide in wastewater with micro-distillation applying amperometric detection
Cyanide in wastewater is an important parameter to measure for health requirements. Free, weakly complexed, and strongly complexed cyanide can be differentiated. Direct measurement in the wastewater is not feasible due to the matrix itself. Therefore, total cyanide is determined after acidification of the sample, which releases all cyanide from complexes, and subsequent distillation and absorption of cyanide in an alkaline solution. Amperometric detection is applied using a gold working electrode. This electrode is advantageous over the silver electrode due to less contamination issues and better long-term stability.
- AN-EC-041Studying nickel deposition with EQCM-D and EC-Raman
This application note demonstrates EQCM D for simultaneous mass and dissipation analysis of Ni(OH)₂ electrodeposition.
- AN-EC-035Using a portable standalone system for easy fermentation monitoring
By using an enzymatic sensor with a screen-printed electrode, producers can measure lactic acid production, thereby monitoring fermentation processes.
- AN-V-219Sn(II) in radiopharmaceuticals
Sodium pertechnetate (99mTc) radiopharmaceuticals are widely used in medical imaging diagnostic procedures to help diagnose a large number of diseases affecting the bones and major organs. These radiopharmaceuticals are usually prepared from cold kits consisting of several ingredients, including a reducing agent. Sn(II) is a typical reducing agent which reduces the Tc(VII) that is added to the cold kit to a lower oxidation state which then forms the stable organic complex.For quality control, the tin content has to be determined in the kit vial. Sn(II) can be selectively determined using differential pulse polarography. Polarography is a straightforward, sensitive, selective, and interference-free method for the determination of mg/L levels of Sn(II) in radiopharmaceuticals.
- 8.000.6021Water analysis
A complete tap water analysis includes the determination of the pH value, the alkalinity and the total water hardness. Both the pH measurement and the pH titration by means of a standard pH electrode suffer from several drawbacks. First, the response time of several minutes is too long and, above all, the stirring rate significantly influences the measured pH value. Unlike these standard pH electrodes, the Aquatrode Plus with its special glass membrane guarantees rapid, correct and very precise pH measurements and pH titrations in solutions that have a low ionic strength or are weakly buffered. Total water hardness is ideally determined by a calcium ion-selective electrode (Ca ISE). In a complexometric titration, calcium and magnesium can be simultaneously determined up to a calcium/magnesium ratio of 10:1. Detection limits for both ions are in the range of 0.01 mmol/L.
- AN-T-096Acid number in lubricants with potentiometric titration
Fresh as well as used petroleum products may contain acidic components as additives or degradation products. The acid number (AN) is a measure for the relative amount of acids present expressed as mg KOH per g sample. Moreover, AN is used as a quality parameter of lubricating oils both for assessing the quality of new formulations and as an indicator for the degradation of such formulations during service. The use of a pH electrode suitable for non-aqueous titrations ensures the reliable determination of the equivalence point. A flexible sleeve diaphragm facilitates its cleaning especially after use in heavily contaminated samples, such as in used engine oils. Using the correct electrode greatly increases the precision and reliability of the results. This Application Note describes the potentiometric determination of the acid number according to ASTM D664 and IP 177 using the pH electrode Solvotrode easyClean.
- 8.000.6029Determination of copper in fuel ethanol for car engines by anodic stripping voltammetry
The presence of copper in fuel ethanol blends has gained considerable attention, since Cu2+ catalyzes oxidative reactions in gasoline leading to a deterioration of olefins and the formation of gum. Anodic stripping voltammetry (ASV), one of the most sensitive and accurate techniques for trace-metal analysis, has been demonstrated for the determination of Cu(II) in ethanol/gasoline blends without any sample pretreatment. Copper ions are first electrodeposited onto the surface of a hanging mercury drop electrode (HMDE) before the amalgamated copper is quantitatively stripped (anodically dissolved), a current-voltage curve being recorded.Experimental conditions such as deposition time and potential as well as the suitable electrolyte and reference electrode were determined in preliminary experiments. For synthetic samples spiked with Cu2+ (5…100 µg/L), recovery rates between 96 and 112% were obtained. The copper-spiked E85 sample provided a recovery of 100%. The relative standard deviations for Cu2+ concentrations of 5 µg/L and above were 8.0 and 5.5% respectively. Using a preconcentration time of 60 s at -0.7 V versus Ag/AgCl, a linear range of 0…500 µg/L with a detection limit of 2 µg/L was obtained.
- AN-T-180Determination of the acid number and base number in used motor oil by differential amplification
For titrations in low conducting media (e.g., non-aqueous titrations) the potentiometric indication can be disturbed by interfering signals. When differential amplification is used, these signals are measured by both the measuring electrode and the reference electrode and thus neutralized. It is therefore possible to obtain smoother titration curves and more reproducible results.This Application Note describes the potentiometric determination of the acid number and base number in used motor oil by the differential amplification using a fully automated OMNIS system.
- AN-EC-038Measuring ionic conductivity using screen-printing technology
Using disposable 11COND screen printed electrodes and electrochemical impedance spectroscopy, conductivity in drinking water can be measured using only 100 µL samples.
- AB-068Potentiometric determination of carboxyl and amino terminal groups in polyamide fibers
Indication of the titration endpoint of the weakly alkaline or weakly acidic terminal groups in non-aqueous solution is frequently not easy. An improvement is possible by using a suitable titrant (TBAH = tetrabutylammonium hydroxide for terminal carboxyl groups; perchloric acid for terminal amino groups).An improvement in the evaluation can also be achieved by choosing benzyl alcohol as the solvent.The choice of electrode combination and the measuring setup is also important. Differential potentiometry using the three-electrode technique results in a great improvement in titrations in poorly conducting solutions. Noisy signals are eliminated.
- AN-SENS-001Quantification of paracetamol with square wave voltammetry
This Application Note demonstrates square wave voltammetry for sensitive, reproducible quantification of paracetamol using a screen-printed electrode and INTELLO.
- AN-EC-031Monitoring ferrocyanide oxidation using hyphenated EC-Raman
This Application Note highlights the use of Metrohm Hyphenated EC-Raman Solutions to monitor the reversible oxidation of ferrocyanide at a gold electrode.
- AN-BAT-006Determination of the MacMullin number
The main components of a battery are the positive and negative electrodes, together with the electrolyte, which provides only the ionic conductivity. The most common electrolytes are in the liquid state. Therefore, a separator is needed to provide a physical separation between the electrodes. The separator is soaked with electrolyte. The MacMullin number is a parameter used to determine the quality of a separator, in terms of ionic conductivity, when soaked with an electrolyte. The MacMullin number can be calculated, using the results of data fitting of two EIS experiments and the geometric factors of the measurement cells. In this application note, a commercial electrolyte is employed, together with a porous filter, used as a separator.
- AN-V-209Carbonyl test methods for alcohols
This polarographic method uses the Multi-Mode Electrode Pro for simultaneous detection of carbonyl impurities in alcohols, ensuring high product quality and stability.
- AB-143Determination of complexing agents in detergents
Application Bulletin AB-076 contains a description of the polarographic determination of low concentrations (1–100 mg/L) of NTA and EDTA in bodies of water. NTA, EDTA and citrate have gained in importance as complexing agents and builders due to the fact that the laws of some countries have made it necessary to find a substitute for phosphates in detergents.This Bulletin describes the determination of larger quantities of complexing agents in detergents using potentiometric titration. The ion-selective copper electrode (Cu-ISE) is used here as the indicator electrode. The determination of complexing agents is not disturbed by the other constituents often present in detergents.
- AN-N-040Cyanide in a standard solution using the Metrosep A Supp 1 - 250/4.6 column
Determination of cyanide using anion chromatography with amperometric detection at the silver electrode.
- AN-I-008Sulfide content of wastewater
Determination of sulfide in wastewater by direct potentiometry with the Ag/S ion-selective electrode.
- AN-S-077Traces of iodide in common salt using amperometric detection
Determination of iodide in common salt using anion chromatography with amperometric detection at the silver electrode.
- AN-T-008Sulfate in brine
Determination of sulfate in brine by indirect potentiometric titration with EGTA using platinum and tungsten electrodes.
- AN-T-009Sulfate in cement
Determination of sulfate in cement by indirect potentiometric titration with EDTA using platinum and tungsten electrodes.
- AN-T-033Lidocaine in ointments
Determination of lidocaine in ointments by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.
- AN-T-106Fully automated determination of calcium in milk
In this Application Note, the determination of calcium in milk is shown with the copper ion-selective electrode which is less sensitive to contamination from proteins.
- AN-P-082Sulfite determination in food and beverages applying amperometric detection
Sulfite is found in many drinks, dried fruit, snacks etc. It acts as a preservative and may be added artificially or can be a side product of fermentation. As sulfite can induce a health risk, it is banned in raw foods and must be labeled on processed foods. Analysis of sulfite by IC with DC amperometric detection is nearly impossible due to the food matrix which fouls and deactivates the electrode surface very fast. The new automatic CV activation procedure (CV treatment, patent pending) cleans the electrode surface and recovers its sensitivity. This report shows DC amperometric detection of sulfite in several foodstuffs applying this activation step prior to the sulfite detection.
- AN-N-027Traces of bromide and iodide using amperometric detection
Determination of traces of bromide and iodide using anion chromatography with amperometric detection at the silver electrode.
- AN-T-031Na2O (free base) and SiO2 (silicate) in water glass
Determination of Na2O and SiO2 in water glass by potentiometric titration with HCl using the Sb electrode.
- AN-N-022Traces of iodide in hydrochloric acid (25%) using amperometric detection
Determination of traces of iodide in HCl (25%) using anion chromatography with amperometric detection at a silver electrode.
- AN-N-028Traces of bromide in hydrochloric acid (32%) using amperometric detection
Determination of traces of bromide in HCl (32%) using anion chromatography with amperometric detection at the silver electrode.
- AN-T-035Tranexamic acid in injection solutions
Determination of tranexamic acid in injection solutions by nonaqueous potentiometric titration with perchloric acid using a glass electrode.
- AN-T-037Nitrogen content of nitrocellulose
Determination of the nitrogen content of nitrocellulose by potentiometric titration with Fe(II) using a combined Pt electrode.
- AN-T-039Free alkali in sodium hypochlorite
Determination of free alkali in sodium hypochlorite by potentiometric titration with hydrochloric acid using a combined glass electrode.
- AN-T-040Determination of phenylglycine content
Determination of phenylglycine through nonaqueous potentiometric titration with sodium methylate using a special combined glass electrode. Keyword: Antibiotics
- AN-N-025Traces of nitrite, thiosulfate, and iodide using amperometric detection
Determination of traces of nitrite, thiosulfate, and iodide using anion chromatography with amperometric detection at the carbon paste electrode.
- AN-N-038Traces of iodide in acetic acid using amperometric detection
Determination of traces of iodide in acetic acid using anion chromatography with amperometric detection at the carbon paste electrode.
- AN-N-066Four phenols in tap water using amperometric detection
Determination of phenol, m-cresol, 2,6-dimethylphenol and 2,3,6-trimethylphenol in tap water with amperometric detection using a glassy carbon electrode.
- AN-P-035Four phenols in tap water by amperometric detection
Determination of phenol, m-cresol, 2,6-dimethylphenol, and 2,3,6-trimethylphenol in tap water using amperometric detection and a glassy carbon electrode.
- AN-S-071Traces of chlorite and nitrite using amperometric detection
Determination of chlorite and nitrite using anion chromatography with amperometric detection at the carbon paste electrode after chemical suppression.
- AN-T-016Nonionic surfactants in compact washing powders
Determination of nonionic surfactants in compact washing powders by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.
- AN-T-043Bromine index in low-level standards
Determination of the bromine index in low-level standards by bivoltametric titration with bromide/bromate using a double Pt electrode.
- AN-T-046Soap content of soap noodles
Determination of the soap content of soap noodles by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.
- AN-T-104Fully automated determination of barium in aqueous solution
This Application Note describes the fully automated complexometric determination of barium in aqueous solutions with a copper ion-selective electrode.
- AN-T-107Fully automated determination of total iron in cement
This Application Note describes the fully automated complexometric determination of total iron in cement with a copper ion-selective electrode.
- AN-T-114Iodometric determination of ascorbic acid in orange juice
This Application Note describes the iodometric, bivoltametric determination of ascorbic acid in orange juice using the Double Pt-sheet electrode.
- AN-T-050Nonionic surfactant nonylphenol ethoxylate (8 EO)
This application note describes the determination of nonylphenol ethoxylate by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.
- AN-T-027Alkalinity of amine-containing gas washing solutions
Determination of the alkalinity of gas washing solutions containing alkanolamines by potentiometric titration with sulfuric acid using the combined glass electrode.
- AN-T-049Cationic surfactants in a household cleaner by potentiometric two-phase titration
Determination of cationic surfactants in a household cleaner by potentiometric two-phase titration with sodium dodecylsulfate using the «Surfactrode Resistant» electrode.
- AN-N-039Iodide in wastewater (dye industry) using dialysis for sample preparation
Determination of iodide in wastewater (dye industry) using anion chromatography with amperometric detection at the silver electrode and dialysis for sample preparation.
- AN-T-013Cationic surfactant (cetrimide) in an antiseptic disinfectant
Determination of the cationic surfactant «cetrimide» in an antiseptic disinfectant by potentiometric titration with sodium dodecyl sulfate using the «Ionic Surfactant» electrode.
- AN-S-070Trace anions in wastewater (photographic industry) using amperometric detection
Determination of iodide and thiosulfate in photographic process wastewater using anion chromatography with amperometric detection at the carbon paste electrode after chemical suppression.
- AN-T-047Soaps and anionic surfactants in washing powder by potentiometric two-phase titration
Determination of soaps and anionic surfactants in washing powder by potentiometric two-phase titration with TEGO®trant A100 using the «Surfactrode Resistant» electrode.
- AN-T-036Benzydamine hydrochloride in a disinfectant solution
Determination of benzydamine hydrochloride {1-benzyl-3-[3-(dimethylamino)-propoxy]-1H-indazole hydrochloride} in disinfectant solution by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.
- AN-T-064Titanium and iron in mixtures
Simultaneous determination of titanium and iron by potentiometric titration with potassium dichromate using a platinum electrode. Before determination, Ti4+ and Fe3+ are reduced with Cr2+.
- AN-V-068Cadmium and lead in seawater
Cd and Pb can be determined in seawater samples in the ng/L concentration range by anodic stripping voltammetry on a mercury film electrode (MFE).
- AN-T-125Automatic determination of cadmium in aqueous solution with the Cu ISE
This application note describes the analysis of cadmium in aqueous solution using a copper ion-selective electrode with Cu-EDTA complex used as an indicator.
- AN-V-045Uranium in drinking water
Uranium can be determined in drinking water by adsorptive stripping voltammetry (AdSV) at the hanging mercury drop electrode (HMDE). Chloranilic acid is used as complexing agent.
- AN-T-126Automatic determination of cobalt in aqueous solution with the Cu ISE
This application note describes the fast, accurate determination of cobalt with a copper ion-selective electrode (Cu ISE) and Cu-EDTA complex as an indicator.
- AN-V-118Gold in ammonium thiosulfate solution
Gold can be determined by anodic stripping voltammetry (ASV) in the µg/l range at the Ultra Trace Graphite electrode. The solution should not contain halide ions.
- AB-404Total acid number titration of petroleum products
The determination of the acid number plays a significant role in the analysis of petroleum products. This is manifested in the numerous standard procedures in use over the world (internal specifications of multinational companies, national and international specifications of ASTM, DIN, IP, ISO, etc.). These procedures differ mainly in the composition of the used solvents and titrants.This bulletin describes the determination of the acid number in petroleum products by applying different types of titration.The potentiometric determination is described according to ASTM D664, the photometric according to ASTM D974 and the thermometric titration according to ASTM D8045.
- AN-T-115Bivoltametric titration with 2,6-dichlorophenol indophenol for the determination of ascorbic acid in orange juice
This Application Note describes the bivoltametric titration of ascorbic acid in orange juice. 2,6-dichlorophenol indophenol (DPIP) is used as titrant; endpoint determination takes place using the Double Pt-sheet electrode.
- AN-RA-006New strategies for obtaining the SERS effect in organic solvents
Many electrochemical methods have been developed but are traditionally limited to aqueous media. Raman spectroelectrochemistry in organic solutions is an interesting alternative, but developing new EC-SERS procedures is still required. This Application Note demonstrates that the electrochemical activation of gold and silver electrodes enables the detection of dyes and pesticides in organic media.
- AN-T-163Complexometric titration of aluminum chloride with OMNIS
OMNIS is the ideal system for quick and accurate determination of aluminum in aluminum chloride using complexometric back titration with an ion-selective copper electrode (Cu-ISE). Copper sulfate is used as the titrant.
- AN-V-089Mercury in wastewater
Mercury can be determined in wastewater by anodic stripping voltammetry (ASV) on a gold rotating disk electrode (Au RDE). After the addition of hydrochloric acid and hydrogen peroxide, digestion is done by UV irradiation.
- WP-058Virus detection: Fast, sensitive, and cost-effective with electrochemical testing
With significant global viral outbreaks becoming the norm rather than generational outliers, it is imperative that fast, sensitive, and cost-effective testing is available to the masses. Screen-printed electrodes (SPEs) allow rapid, widespread testing of populations for infectious disease, without the need of skilled personnel or burdensome equipment in the field. The possibility of point-of-care (POC) testing with SPEs has been exhibited in several recent studies. Metrohm DropSens combines high production capabilites of custom-made SPEs with a valid ISO 13485 certification "Manufacturing of sensors for medical devices", meaning testing procedures developed on these SPEs can be reliably scaled up for larger operations, with easier regulatory approval for commercialization.
- AN-I-011Fluoride content in drinking water
Fluoride content in drinking water can be determined quickly and conveniently with the help of potentiometric titration and the ion-selective fluoride electrode (F-ISE). The F-ISE is calibrated with suitable standard solutions before the measurement.
- AN-I-015Determination of the chloride content in dye
In the synthesis of certain dyes, sodium chloride is a byproduct. The content of chloride is therefore an important parameter. This Application Note describes the determination of the chloride content in dye by standard addition using a Cl- ion-selective electrode.
- AN-EC-007Differences between digital scans, analog scans, and signal integration
In this Application Note, analog and digital staircase potential signals are applied to a platinum working electrode in an acidic solution. The differences in measured currents are highlighted and compared with a similar experiment where the current is being calculated from the measured charge.
- 8.000.6048Fully automated determination of fluoride in blood samples
Sodium fluoride is used as a preservative in biological samples for alcohol analysis. All submitted blood samples, including those taken from vehicle drivers suspected of driving under the influence of liquor, have to be tested for adequate preservation prior to alcohol determination by gas chromatography. This is critical to ensure adequate sample preservation. Inadequate sample preservation may allow glycolysis and/or microorganism growth to produce ethanol.In the past this has been done by direct potentiometric measurement using a fluoride-selective electrode (F ISE), an ion meter and certified NaF standards. The sodium fluoride level was determined manually by dipping the electrode directly into the blood sample. Results were recorded manually. This poster describes two independent automated methods of analysis that allow the minimization of this tedious and time-consuming procedure.In the first one, the fluoride content in a blood aliquot is measured by direct potentiometric measurement after the addition of TISAB and deionized water. The second method employs the titration of the sample aliquot with La(NO3)3 after adding a buffer solution.
- AN-BAT-010Investigation of the Solid Electrolyte Interface Structure and Kinetics.
This application note presents the experimental details and an overview of the most important findings from the EIS and CV experiment to study the structure of a model solid electrolyte interface forming on a planar glassy carbon electrode in contact with a typical organic battery electrolyte.
- AN-EC-024Study of electrochemical kinetics of a classical redox couple using the Autolab Microcell HC
The kinetic and mass transfer parameters of the electro-oxidation reaction of TEMPO were measured using the TSC Surface measuring cell for the Autolab Microcell HC system. The cell allows the study of electrochemical processes in liquid electrolytes in a three electrode configuration under temperature control.
- AN-T-174Determination of hydrolyzable chloride content in liquid epoxy resin in accordance with ASTM D1726 (Method B)
The quantity of hydrolyzable chloride in epoxy resins has an influence on their reactivity and on the properties of the epoxy coating obtained.Rapid and accurate determination is possible with an OMNIS system using potentiometric titration with the dAg ring electrode and silver nitrate as the titrant.
- AN-SEC-002Gathering information from spectroelectrochemical experiments
In-situ spectroelectrochemistry provides dynamic electrochemical and spectroscopic information concurrently with the redox reaction occurring on the electrode surface. Although different spectroelectrochemical configurations can be used, simple equations explain how to relate electrochemistry and spectroscopy for each experimental setup. This Application Note describes how the quantification of one electrochemical parameter (the diffusion coefficient) is calculated from the spectroscopic data as a proof of this concept.
- AN-EC-019How to use a convolution method in voltammetric analysis
Convolution voltammetry consists essentially of a voltammetric, chronoamperometric, or chronocoulometric experiment followed by a mathematical transformation - convolution. Using a convolution method, the effect of the decrease of the concentration gradient can be eliminated from the total response of the electrode. This application note explains how the convolution in NOVA works.
- AN-T-034Hydrofluoric and nitric acid in etching baths
Determination of hydrofluoric and nitric acid in etching baths by potentiometric titration.a) Determination of the total acid content using the combined Sb electrode and NaOH as titrant.b) Determination of hydrofluoric acid using the F-ISE and the titrant La(NO3)3.The concentration of nitric acid is then determined by calculation.
- AB-190Determination of 4-carboxybenzaldehyde in terephthalic acid by polarography
4-Carboxybenzaldehyde, in the following referred to as 4-CBA, can be reduced directly at the dropping mercury electrode (DME) in an ammoniacal solution. After a very simple sample preparation it is now possible to determine the concentration of 4-CBA in terephthalic acid quickly and precisely by polarography down to the lower ppm range.
- AN-T-191Determination of the silver in silver jewelry alloys according to EN ISO 11427 and GB/T 17832
The knowledge of the exact silver content of silver allows used for jewelry is very important to ensure the quality of jewelry. Therefore, the determination procedure is regulated internationally and nationally. A common approach is the titration with potassium bromide after an acidic digestion of the silver using a silver electrode for indication.
- AB-097Determination of tocopherols (vitamin E) in edible oils and fats by anodic stripping voltammetry at a glassy carbon RDE
Edible oils and fats contain natural tocopherols and, in some cases, also synthetic tocopherols added as antioxidants. The method described below allows the simple and rapid determination of the tocopherol content by voltammetry. The tocopherols are oxidized electrochemically at the glassy carbon electrode (GCE). The limit of quantitation is approximately 5 ppm (mg/kg) tocopherol.
- AN-P-073Glucose and galactose in 2% lactose using amperometric detection applying Empower 3.0
This Application Note shows the determination of glucose and galactose in a 2% solution of lactose. The separation is achieved on a Hamilton RCX-30 - 250/4.6 applying pulsed amperometric detection (PAD) at a gold electrode. Instrument control, data acquisition, and data handling is done by Empower 3.0 using the Metrohm IC Driver 2.0 for Empower.
- AN-EC-008Basic overview of the working principle of a potentiostat/galvanostat (PGSTAT) – electrochemical cell setup
A basic overview of the working principle of a potentiostat/galvanostat is presented. Depending on the application, the connections of the instrument to the electrochemical cell can be (or must be) set up in different ways. Below, the three commonly used electrochemical cell setups are discussed together with the role of the electrodes used in electrochemical measurements.
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