In severe cases of cyanide poisoning, sodium nitrite is used along with sodium thiosulfate for treatment. This Application Note describes the nitrite ion chromatography assay with the Metrosep A Supp 4 column and suppressed conductivity detection. This column equivalency study was in cooperation with the USP according to the USP General Chapter <621>.

Nitrosamine presence in medicines, even at trace level poses high safety risks to patients (carcinogenic). Nitrosamine formation can be avoided by controlling and monitoring the nitrite concentration in pharmaceutical products and substances. This Application Note describes the analysis of nitrite in duloxetine hydrochloride with ion chromatography (IC).

Nitrosamine formation can be avoided by controlling the nitrite concentration in pharmaceutical products and processes. To monitor nitrosamine formation, sensitive analytical methods such as ion chromatography for the determination of nitrite in pharmaceutical products and substances are essential.

N-Methylpyrrolidone (NMP) is crucial for lithium-ion battery production. Metrohm’s intelligent Preconcentration Technique with Matrix Elimination enables µg/L-level anion analysis in NMP.

The Metrosep A Supp 21 column and 948 Continuous IC Module, CEP enable efficient, automated single-run analysis of major anions and disinfection byproducts in water.

Supercapacitors (also known as ultracapacitors, electrochemical capacitors, or double-layer capacitors) are electrochemical devices that have the ability to store and release charge and deliver high power densities over short periods of time. Their ability to store electrical energy efficiently and release electrical energy very quickly make them ideally suited for applications where short time backup power and peak power needs are critical.

Spectroelectrochemical experiments not only provide outstanding qualitative information about samples, but also offer other quantitative data that can be considered when performing analyses. A single set of experiments allows analysts to obtain two calibration curves: one with the electrochemical data and another with the spectroscopic information. The concentration of tested samples is calculated by using both curves, confirming the obtained results by two different routes. In this Application Note, comparison between electrochemical and spectroscopic determinations demonstrates that the two methods measure uric acid (UA) indistinctively, with close agreement of the calculated values with empirical data.

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.

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.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most promising ICPs due to its high conductivity, electrochemical stability, catalytic properties, high insolubility in almost all common solvents and interesting electrochromic properties (transparent in the doped state and colored in the neutral state). In this Application Note, PEDOT film is evaluated by spectroelectrochemical techniques.

This Application Note demonstrates square wave voltammetry for sensitive, reproducible quantification of paracetamol using a screen-printed electrode and INTELLO.

This Application Note presents DPV as a sensitive, selective method for detecting heavy metals in water, detailing setup, parameters, and advantages over other techniques.

Determination of chloride in canned vegetables by potentiometric titration with silver nitrate using the Ag-Titrode.

In order to maintain product quality, the sodium chloride content in meat products must be monitored, as the limit values defined by the respective public health authorities must not be exceeded. The chloride content in food correlates with the salt content, its determination is therefore described in various norms and standards. However, preparation of meat samples is time consuming, as it requires homogenization with a mixer and a chloride extraction with water. In order to reduce workload and working hours, this Application Note describes a fully automatic potentiometric titration of chloride with silver nitrate in meat products based on ISO 1841-2, including fully automated sample preparation using a Polytron homogenizer.

Determination of trace chloride in cement and clinker by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of sulfate in brine by indirect potentiometric titration with EGTA using platinum and tungsten electrodes.

Determination of sulfate in cement by indirect potentiometric titration with EDTA using platinum and tungsten electrodes.

Determination of anionic surfactants in shower lotions and shampoos by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.

Determination of anionic surfactants in a nickel plating bath by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.

Determination of cationic surfactants in hair conditioner by potentiometric titration with dioctyl sodium sulfosuccinate using the «Ionic Surfactant electrode.

Determination of the cationic surfactant «cetrimide» in an antiseptic disinfectant by potentiometric titration with sodium dodecyl sulfate using the «Ionic Surfactant» electrode.

Determination of chlorhexidine in wash lotion by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.

This application note shows a reliable way to determine the content of non-ionic surfactants in liquid cleaning solutions by potentiometric titration.

Determination of nonionic surfactants in compact washing powders by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.

Determination of ampicillin in raw and pure products through potentiometric titration with Hg(II) using the combined Au electrode. Keyword: Antibiotics

Determination of total penicillin content through potentiometric titration with Hg(II) using the combined Au electrode. Keyword: Antibiotics

Simultaneous determination of cyanide and silver in a silver plating bath by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of Cr(VI) and Cr(III) in chromium baths by iodometric potentiometric titration with thiosulfate using the combined Pt electrode.

Determination of Sn(II) and sulfuric acid in an acidic tin plating bath by potentiometric titration.

Determination of cyanide in alkaline plating baths by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of hydroxide and carbonate in alkaline plating baths by potentiometric titration with HCl using the combined glass electrode.

Determination of cadmium, copper, lead, and zinc in alkaline plating baths by potentiometric titration with EDTA using the Cu-ISE.

Peroxides are often used for disinfection and water treatment purposes due to their antiseptic properties. Lower concentrations between 0.3–3% are used in households, while higher concentrations can be used for sterilization purposes. Additionally, peroxides are utilized as oxidizing and bleaching agents. Peroxides, perborates, and percarbonates can easily be determined by titration. This application note presents two titration methods for peroxide analysis: ASTM D2180 for concentrated hydrogen peroxide solutions, and a second method for trace determination of hydrogen peroxide, suitable for concentrations as low as 0.4 mg/L.

Determination of perborate, percarbonate, or persulfate in washing powder by iodometric potentiometric titration using the Pt-Titrode.

Determination of the alkalinity of gas washing solutions containing alkanolamines by potentiometric titration with sulfuric acid using the combined glass electrode.

Simultaneous determination of hydrogen sulfide and mercaptans in petroleum products by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of alkyllead compounds in petrol (gasoline) after reaction with iodine monochloride by potentiometric titration with EDTA using the Cu-ISE.

Determination of Na2O and SiO2 in water glass by potentiometric titration with HCl using the Sb electrode.

This Application Note presents a potentiometric titration method for trace H2S analysis in water on an OMNIS system using silver nitrate and an Ag Titrode.

Determination of lidocaine in ointments by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.

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.

Determination of tranexamic acid in injection solutions by nonaqueous potentiometric titration with perchloric acid using a glass electrode.

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.

Determination of the nitrogen content of nitrocellulose by potentiometric titration with Fe(II) using a combined Pt electrode.

Determination of the iron content of iron powder by potentiometric titration with potassium dichromate using the Pt-Titrode.

Determination of free alkali in sodium hypochlorite by potentiometric titration with hydrochloric acid using a combined glass electrode.

Determination of phenylglycine through nonaqueous potentiometric titration with sodium methylate using a special combined glass electrode. Keyword: Antibiotics

Citric acid and oxalic acid are present in many products, such as foods or chemical solvents (e.g., decontamination solutions). Both acids are reducing agents and citric acid is additionally a powerful antioxidant. Due to their mutual impact (buffer effect), a content calculation is only possible with correction factors for each acid. A fast and accurate determination by potentiometric titration using the dEcotrode plus and sodium hydroxide as titrant can be realized in this Application Note.

Determination of the bromine index in low-level standards by bivoltametric titration with bromide/bromate using a double Pt electrode.

Determination of acetate, chloride, and phosphate in an infusion solution by potentiometric titration with sodium hydroxide after conversion of the anions to the corresponding acids.

Determination of the soap content of soap noodles by potentiometric titration with TEGO®trant A100 using the «Ionic Surfactant» electrode.

Determination of soaps and anionic surfactants in washing powder by potentiometric two-phase titration with TEGO®trant A100 using the «Surfactrode Resistant» electrode.

Determination of anionic surfactants in shower oil by potentiometric two-phase titration with TEGO®trant A100 using the «Surfactrode Resistant» electrode.

Determination of cationic surfactants in a household cleaner by potentiometric two-phase titration with sodium dodecylsulfate using the «Surfactrode Resistant» electrode.

This application note describes the determination of nonylphenol ethoxylate by potentiometric titration with sodium tetraphenylborate using the NIO surfactant electrode.

Due to its price and wide availability, the anionic surfactant sodium lauryl sulfate (SLS; SDS) can be found in many detergents as an emulsifier or as a fat solvent e.g., in cleaning or cosmetic products. To avoid causing severe dry skin and hair, and thus skin irritation, regulations in many countries have restricted the sodium lauryl sulfate concentration in ready-to-use products to a range between 0.05–2.5% SLS. To control the concentration of SLS in different products, a titration is carried out with TEGO® trant A100 and the Optrode. The evaluation is done automatically by means of a software, leading to reliable and reproducible results.

Determination of lauryl ether sulfate (LAES) by potentiometric/turbidimetric titration with TEGO®trant A100 using the 610 nm Spectrode.

Determination of calcium in aqueous solutions by photometric titration with EDTA using the 610 nm Spectrode.

Determination of the sum of calcium and magnesium in cement by photometric titration with EDTA using the 610 nm Spectrode.

Determination of aluminum in cement by photometric back-titration of the EDTA excess with zinc sulfate using the 610 nm Spectrode.

Determination of traces of calcium in brine by photometric titration with 1,2-diaminocyclohexanetetraacetic acid using the 610 nm Spectrode.

Determination of nitrite in aqueous solutions by potentiometric back-titration of the added permanganate excess with ammonium iron(II) sulfate using the Pt-Titrode.

Determination of citrate in mineral water drinks by potentiometric titration with copper sulfate using the Cu-ISE. Before the determination, the sample is degassed and passed through a cation-exchange resin.

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+.

Determination of the antihistamine astemizole in raw products by nonaqueous potentiometric titration with perchloric acid using separate electrodes.

Determination of calcium in cheese by potentiometric titration with EGTA using the Cu-ISE.

Tallow amine ethoxylates are toxic to aquatic life, and therefore their use is restricted. This Application Note explains an approach to determine these non-ionic surfactants potentiometrically.

This application note shows how coconut oil ethoxylates can be determined via potentiometric titration.

Determination of iron and nickel in binary mixtures by potentiometric titration with EDTA at different pH values using the Cu-ISE.

Determination of calcium pantothenate by nonaqueous potentiometric titration with perchloric acid using separate electrodes.

Determination of palladium(II) by potentiometric titration with hexadecylpyridinium chloride using the «Ionic Surfactant» electrode.

Determination of reducing sugars in wine and candies according to Fehlings method by potentiometric/iodometric titration using the Pt-Titrode.

The automated system Basic water analysis determines conductivity, pH value, and alkalinity in all kind of water samples. The high degree of automation (e.g., automated sample addition, automated calibration as well as automated titer and cell constant determination) minimizes errors and guarantees an outstanding reproducibility.

In this application note, a fully automated system is presented which allows the determination of several parameters according to various standards within one analysis. These include conductivity (ISO 7888, EN 27888, ASTM D1125, EPA 120.1), the pH value (EN ISO 10523, ASTM D1293, EPA 150.1), alkalinity (EN ISO 9963, ASTM D1067, EPA 310.1), and Ca/Mg content (ISO 6059, ASTM D1126, EPA 130.2). Additionally, the system transfers the required sample volume into an external titration vessel for the analysis, reducing manual sample preparation. Furthermore, all sensors can be automatically calibrated and the titer of each titrant can also be determined.

In this application note, a fully automated system is presented which allows the determination of several parameters according to various standards within one analysis. These include conductivity (ISO 7888, EN 27888, ASTM D1125, EPA 120.1), pH value (EN ISO 10523, ASTM D1293, EPA 150.1), alkalinity (EN ISO 9963, ASTM D1067, EPA 310.1), and chloride content (ISO 9297, ASTM D512, EPA 325.3). Additionally the system transfers the required volume of sample into an external titration vessel, further reducing manual sample preparation. Furthermore, all sensors can be calibrated automatically and the titer of each titrant can also be determined.

In this application note, a fully automated system is presented which allows the determination of several parameters according to various standards within one analysis. These include conductivity (ISO 7888, EN 27888, ASTM D1125, EPA 120.1), pH value (EN ISO 10523, ASTM D1293, EPA 150.1), alkalinity (EN ISO 9963, ASTM D1067, EPA 310.1), Ca/Mg (ISO 6059, ASTM D1126, EPA 130.2), and chloride (ISO 9297, ASTM D512, EPA 325.3). Additionally the system transfers the required volume of sample into external titration vessels for the different analyses, reducing manual sample preparation. Furthermore, all sensors can be automatically calibrated and the titer of each titrant can also be determined.

This Application Note describes the photometric determination of sulfate in aqueous solutions using the Optrode (520 nm). Sulfate is precipitated with an excess of barium chloride solution. Excess barium is subsequently titrated with EDTA.

This Application Note describes the photometric determination of aluminum in cement using the Optrode (574 nm). Following breakdown of the cement sample, the dissolved aluminum is titrated with EDTA. The excess EDTA is titrated back with zinc sulfate solution.

This Application Note covers the photometric determination of calcium in cement using the Optrode (610 nm). After digestion of the cement sample, calcium is titrated with EDTA to the murexide endpoint.

This Application Note describes the digestion of a cement sample and the photometric determination of iron in accordance with DIN EN 196-2 by means of Optrode at 610 nm. Sulfosalicylic acid is used as the indicator and EDTA as the titrant for the determination.

This Application Note is devoted to the photometric determination of magnesium in cement using the Optrode (610 nm). After digestion of a sample aliquot, the magnesium content is determined using EDTA titration.

This Application Note treats the photometric titration of nickel using the Optrode (520 nm). Murexide was used as the indicator and EDTA as the titrant.

This Application Note details the photometric determination of chondroitin sulfate with 1-hexadecylpyridinium chloride as titrant and with the Optrode (660 nm). The method is in compliance with the Ph. Eur. and the USP.

ASTM D8192 describes the photometric titration of the total hardness, calcium hardness, and magnesium hardness in water with an optical sensor for objective endpoint indication, increasing precision and reliability. The method is suitable for both colored and colorless samples such as groundwater, surface water, wastewater, and drinking water. Using a fully automated OMNIS system equipped with an Optrode ensures that the sample preparation and analysis are repeatable.

This Application Note describes the photometric determination of sulfate using the Optrode (610 nm). Sulfate is titrated with a lead nitrate solution; dithizone is used as indicator.

Vitamin C, also known as ascorbic acid or L-ascorbic acid, is an essential nutrient involved in the repair of tissues and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and immune performance, and is also an important antioxidant. This nutrient is found in many foods and is often used as a dietary supplement. This Application Note describes the photometric determination of ascorbic acid according to the standard ISO 6557-2. To increase the objectivity on the determined equivalence point and the reproducibility of the results, an autotitrator equipped with a photometric sensor, the Optrode, is used. The titrant 2,6-Dichlorophenol-indophenol (DCIP or DPIP) simultaneously serves as titrant and indicator.

The carboxyl end groups (CEG) in polymers, such as polyethylene terephthalate (PET), are a measure of the number of unreacted carboxylic acid groups at each end of a polymer chain. The number of CEGs may influence the hydrolysis resistance of geosynthetics, such as geogrids and geotextiles. The lower the CEG value the higher is the hydrolysis resistance of geosynthetics, which in turn increases their stability. This Application Note describes the photometric titration of carboxyl end groups in PET pellets using the Metrohm Optrode. The acidic end groups of the polymer are titrated with an ethanolic KOH solution using bromophenol blue as indicator.

This Application Note describes the photometric determination of bismuth nitrate using the Optrode (520 nm). The sample is titrated with EDTA solution past the endpoint; xylene-orange is used as the indicator. The method for bismuth nitrate fulfills the directives defined in the Ph. Eur. and the USP.

This Application Note looks at the photometric determination of manganese sulfate using the Optrode (610 nm). Manganese is titrated with EDTA; Eriochrome Black T is used as indicator. The method complies with Ph. Eur. and the USP.

This Application Note describes the photometric determination of zinc sulfate using the Optrode at a wavelength of 610 nm. Complexometric titration of zinc requires EDTA as titrant and Eriochrome Black T as indicator. The method fully complies with Ph. Eur. and USP.

This Application Note describes the determination of total content of Ba, Ca, Mg, Pb and Zn in unused lubricating oil by means of the Optrode (610 nm). An excess of EDTA is first added to the metals. Afterwards, the excess EDTA is titrated back with magnesium chloride solution up to the end point of the indicator Eriochrome Black T.

The acid number (AN) of insulating, transformer, and turbine oils is crucial to ensure safe operation, operating equipment control, and corrosion prevention. These oils generally have low AN specifications and their AN determination by manual color-indicator titration is difficult, especially when analyzing colored samples.Using a Titrator with a photometric sensor to detect the end point ensures that the titrations are always carried out under the same conditions. This greatly increases the precision and reliability of the results, which in turn results in improved monitoring for your operations.

Basic additives are added to petroleum products to inhibit corrosion as they have a neutralizing effect on acidic compounds, which are formed as a result of degradation processes. Total base number (TBN) indicates the amount of basic additives present and thus can be used as a measure for the degradation of the petroleum product. Using an automated titration system with a photometric sensor to detect the end point ensures that the titrations are always carried out under the same conditions. This improves the precision and reliability of the results. This Application Notes describes the fully automated photometric determination of TBN in used engine oil using the Metrohm Optrode for the indication of the methyl orange endpoint (at 520 nm).

The automated system MATi 13 determines the permanganate index in all kind of water samples according to EN ISO 8467. The high degree of automation (e.g., automated sample addition, automated titer and blank value determination) minimizes errors and guarantees robust and reproducible results.

Automated mixing of a suspension and a solvent in a 50 mL dosing unit can be used to add a well-defined amount of a suspension-solvent mixture to a sample solution without clogging the dosing unit and tubing by the undiluted suspension. The method is explained by means of the TAN determination of a petroleum sample using thermometric titration. For a better endpoint recognition, small amounts of a paraformaldehyde-solvent suspension are added (catalyzed endpoint thermometric 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.

Basic chemicals are added to petroleum products to prevent corrosion as they neutralize acidic components that form during the use and aging of these products. The base number (BN) gives an indication regarding the amount of these basic additives present, and it can be used as a measure for the degradation of the petroleum product. This Application Note describes the potentiometric determination of the base number according to ISO 3771, ASTM D2896, and IP 276 using the Metrohm Solvotrode easyClean and a fully automated OMNIS system.

This Application Note describes the conductometric determination of the total base number in engine oil according to IP 400.

The present Application Note describes an automated system with which the acidity can be determined in a wide variety of juice samples. The high degree of automation (e.g., automated calibration and titer determination) reduces errors to a minimum and offers outstanding reproducibility.

Acid copper baths are mainly used for the copper deposition on semiconductor wafers. Small amounts of chloride increase the speed of deposition and reduce anode polarization. However, higher concentrations are undesired, as this will decrease the quality of the copper deposition. Therefore, it is quite important to monitor the amount of chloride to have an effective, yet high-quality copper deposition process. In this Application Note, a fully automated solution based on titration is presented. In comparison to ion chromatography, titration offers the benefit that no dilution of the sample is necessary, and the hardware is comparatively low-priced. Furthermore, the fully automated solution allows users to minimize handling errors, to reduce workloads, and to guarantee outstanding reproducibility.

This Application Note describes an automated system with which the chloride content in various water samples can be determined. The high degree of automation (e.g., automated addition of acid and titer determination) reduces errors to a minimum and ensures outstanding reproducibility.

Titrants are normally bought ready to use. However, it is necessary to determine the accurate concentration of your titrant solution on a regular basis using a primary standard. To correct the mentioned variation, a so-called «titer factor» is applied. The titer can be easily and quickly assessed by using the Metrohm brand of autotitrators. Predefined calculation formulas implemented in Metrohm titrators or software, respectively, as well as the automatic storage of the titer factor, makes standardization a simple task.

In many countries, the aluminum concentration in water is limited to 0.2 mg/L. This application note shows how the analysis of aluminum in water can be done fully automatically by complexometric titration with EDTA.

This Application Note describes the fully automated complexometric determination of barium in aqueous solutions with a copper ion-selective electrode.

This application note shows how to determine the bismuth content automatically in aqueous solution with potentiometric titration.

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.

This Application Note describes the fully automated complexometric determination of total iron in cement with a copper ion-selective electrode.

This Application Note describes the fully automated complexometric determination of zinc(II) in aqueous solutions with a copper ion-selective electrode.

Esta Nota de Aplicação apresenta um método modificado para economizar tempo para determinar o valor de iodo (IV) em óleos comestíveis com base em vários padrões (EN ISO 3961, ASTM D5554, etc.).

This Application Note details a method to determine the peroxide value of edible fats and oils based on EN ISO 27107, EN ISO 3960, AOAC 965.33, Ph.Eur. 2.5.5, and USP<401>.

The saponification value evaluates edible oil quality by indicating the average molecular weight of fatty acids. Its titrimetric determination in canola and olive oil is described here.

This Application Note describes the titration of acid value and free fatty acids in different edible oils, based on the standards EN ISO 660, USP<401>, and Ph.Eur. 2.5.1.

The hydroxyl number (HN) is an important sum parameter for quantifying the presence of hydroxyl groups in chemicals. As a key quality parameter, it is determined in various substances. For pharmaceutical samples, USP chapter <401> and Ph. Eur. Chapter 2.5.3 describe the determination. However these methods either use toxic pyridine and require refluxing or have long reaction times. In this Application Note, an alternative method according to ASTM E1899 is presented. This method is pyridine-free and does not require refluxing or long reaction times. The determination is performed at room temperature with only a small sample size. The analysis including all preparation steps is performed with a fully automatic OMNIS system. This allows parallel analysis of multiple samples, increasing productivity in the laboratory by 50%.

This Application Note describes the iodometric, bivoltametric determination of ascorbic acid in orange juice using the Double Pt-sheet electrode.

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.

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.

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.

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.

This Application Note describes an automated system with which the chloride content in bouillon can be determined. The high degree of automation (e.g., automatic addition of acid and titer determination) reduces errors to a minimum and ensures outstanding reproducibility.

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.

This application note shows the use of an ion-selective copper electrode to measure the indium concentration in an aqueous solution.

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.

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.

Copper can be determined using photometric titration with EDTA at a wavelength of 520 nm.

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.

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.

This Application Note describes the automated complexometric determination of copper with the Cu ISE.

Magnesium can be determined with the Cu ISE. A small amount of Cu-EDTA complex is used as an indicator, as the Cu ISE is not selective for magnesium itself.

Nickel can be determined with the Cu ISE. A small amount of Cu-EDTA complex is used as an indicator, as the Cu ISE is not selective for nickel itself.

Lead can be analyzed with the Cu ISE. Diammonium tartrate is added to the solution to prevent the precipitation of lead hydroxide in the alkali titration medium.

Water hardness is often determined photometrically using two different indicators and while performing the determination at two different pH values. Additionally, the determination itself is subjective, as the color change is determined by the analyst and not by an analytical device. This application note introduces a more robust option to easily assess calcium, magnesium, and total hardness in water by using the Cu-ISE and two different titrants. Sample preparation is identical for both analyses and can therefore be automated without any issues.

The titratable acidity gives an indication of the freshness of milk and yogurt as well as other fermented milk products. The determined titratable acidity in milk is mainly given through the absorption of hydroxyl ions by milk proteins and milk salts. The acidity increases with bacterial acidification and with enzymatic lipolysis. The titratable acidity corresponds to the amount of sodium hydroxide required to titrate 100 g sample to a pH value of 8.30. In this Application Note, an easy and accurate method to determine the titratable acidity in milk according to DIN 10316 and in yogurt according to ISO/TS 11869 and IDF/RM 150 is demonstrated.

In order to maintain product quality, the sodium chloride content in dairy products must be monitored and not exceed the limits defined by the respective public health authorities. The chloride content in food correlates with the salt content, its determination is therefore described in various norms and standards. However, preparation of such samples is time consuming, as it includes a chloride extraction with warm water. Whole milk powders in particular are difficult to handle as an inhomogeneous dispersion of fat in the titration suspension occurs. In order to reduce the workload, increase sample throughput, and eliminate the matrix challenges posed by high fat products, this Application Note presents a fully automatic potentiometric titration of chloride with silver nitrate in milk and milk powder based on ISO 21422, IDF 242, AOAC 2015.07, AOAC 2015.08 and AOAC 2016.03

The salt content in food is a critical parameter, given that the WHO recommends a maximum daily intake of 5 g for an adult. In butter with a salt content exceeding 0.1%, it can be determined by a precipitation titration of chloride with silver nitrate. However, during manual titration the operator cannot leave the system unattended because he has to exchange the sample beakers manually which is time consuming and prone to errors. This Application Note describes the automated determination of chloride in salted butter in accordance with ISO 15648, ISO 21422, IDF 179 and IDF 242. If automated according to the norms and standards, salt determination can be performed completely unattended with superior reproducibility of results increasing efficiency in the laboratory.

The WHO recommends a maximum daily intake of 5 g salt for an adult. The chloride content in food correlates with the salt content, its determination is therefore described by various standards. In cheese and cheese products with a chloride content higher than 0.2%, chloride is usually determined by a precipitation titration with silver nitrate. However, time-consuming sample preparation is required, as the cheese has to be homogenized and the chloride extracted with hot water. This Application Note describes the fully automatic determination of chloride in cheese according to EN ISO 5943, ISO 21422, IDF 242 and IDF 88 including sample preparation with a Polytron homogenizer. This increases productivity due to a higher sample throughput and lower work load for the operator.

The epoxy content of epoxy resins has a strong influence on the reactivity of the resins as well as on the properties of the coating obtained from the resin curing process. The epoxy content is thus an important quality control parameter for manufacturers as well as consumers. This analysis is based on the reaction of hydrogen bromide with the epoxy groups of the sample. Hydrogen bromide in turn is produced by the reaction of tetraethylammonium bromide (TEABr) with standardized perchloric acid. The standards EN ISO 3001 and ASTM D1652 describe the determination of the epoxy content expressed as epoxy equivalent weight (EEW) by titration. The use of a Titrando and Solvotrode easyClean instead of manual titration greatly increases the reproducibility and repeatability of the determination.

In accordance with the European Pharmacopoeia, sodium sulfate is determined with the PB ISE.

Inorganic sulfate is determined in secondary alklysulfonate (raw material) in accordance with DIN EN 14880 with the use of the Pb ISE.

Barium acetate is used as titrant for conductometric sulfate determination. It can be standardized with desiccated sodium sulfate.

Lead is determined at pH 4 to 5 using back titration with zinc sulfate. Xylenol orange is used as an indicator for visualization of the equivalence point. The equivalence point is detected with the Optrode at a wavelength of 574 mm.

Manganese is determined as Mn(II) in aqueous solutions at pH 10 with Eriochrome Black T as indicator. Ascorbic acid is added to ensure that manganese is present in its bivalent form. The precipitation of water-insoluble manganese hydroxide is prevented by adding triethanolamine (TEA). The Optrode is used for detection at a wavelength of 610 nm.

Barium is analyzed in alkali media using direct titration with EDTA. Phthalein purple is used as the indicator; the equivalence point is determined with the Optrode at a wavelength of 574 nm.

Cobalt is analyzed in aqueous solutions using direct titration with EDTA at a pH value of 9. The indicator is murexide. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Mercury can be determined in alkali media using back titration with zinc sulfate. Eriochrome black T is used as the indicator for this procedure. The Optrode is used for indication at a wavelength of 502 nm.

Palladium is determined at a pH value of 4 to 5 using back titration with zinc sulfate. Xylenol orange is used as the indicator for visualization of the endpoint. The equivalence point is determined with the Optrode at a wavelength of 610 nm.

Tin with EDTA forms very stable complexes in its divalent and tetravalent forms. Hydroxo complexes form in alkali media, which is also why tin is titrated in an acidic medium (pH 2.1). Xylenol orange is used as the indicator. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Thallium is titrated in slightly acidic medium as Tl(III). Xylenol orange is used as the indicator to determine the endpoint. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Zirconium is titrated directly with EDTA in acidic aqueous solution (buffer, pH 1). Eriochrome cyanine R is used as the indicator for this procedure. The equivalence point is determined with the Optrode at a wavelength of 520 nm.

Thorium is titrated with EDTA at a pH value of 4.9. Xylenol orange is used as the indicator for visualization of the equivalence point. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Nickel analysis can be carried out conveniently in alkali media using photometric titration. Murexide is used as the indicator for visualization of the endpoint. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

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.

Potentiometric titration with silver nitrate can be used for the determination of mercaptans in refinery products. This Application Note describes their automatic determination in a middle distillate sample (gas oil).

Cadmium can be determined in aqueous solutions using back titration with zinc sulfate. Eriochrome black T is used as the indicator for this procedure. The equivalence point is determined with the Optrode at a wavelength of 610 nm.

The alpha acid level (AA%) in hops plays a major role in the bitterness they can impart to beer. The AA% can vary between 1% up to 20% in hops. During boiling in the brewing process, alpha acids transform into iso-alpha acids which make the beer bitter. For this reason, it is important for brewers to know the exact AA value of the hops they use. The determination of AA% in hops with conductometric titration according to the EBC method 7.4 is shown in this Application Note.

Alkyl glycosides, alkyl maltosides and compounds with polyoxyethylene groups (POE) are numbered among the nonionic surfactants. These surfactants can be analyzed by standard titration with TEGO®trant following derivatization – in this case following sulfonation.

The purity of sulfanilamide was determined by means of automatic potentiometric titration using sodium nitrite as the titrant. The solution was spiked with potassium bromide, because bromide ions catalyze diazotization titration.

Gallium is determined at a pH value of 4.7 using back titration with zinc sulfate. Xylenol orange is used as the indicator for visualization of the equivalence point. The equivalence point is determined with the Optrode at a wavelength of 610 nm.

The basicity and the CPR (controlled polymerization rate) are very important parameters for the quality of polyols used in polyurethane production. The knowledge of these values is crucial to prevent gelation during handling in the production. In this Application Note their determination by automated, potentiometric titration according to ISO 14899 is described.

Acrylic acid dimerizes spontaneously. Determining the dimer content is, therefore, a key part of the quality control for acrylic acid. One quality control parameter for the dimerization is the acid number. This Application Note describes its determination by automated, potentiometric titration.

The composition of salts with laxative and expectorant effects must be determined precisely in medications. The sulfate content is determined using automatic potentiometric titration with EGTA as titrant in accordance with Ph. Eur. 8.0.

Vitamin C is an important antioxidant and an important component of orange juice. A convenient and precise method for Vitamin C determination in fruit juices is titration, which is also described in numerous standards (ISO 6557/1, ISO 6557/2, AOAC 967.21). OMNIS enables quick and accurate determination of Vitamin C content in orange juice using potentiometric titration with iodine as titrant and a separate double Pt-sheet electrode.

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.

The partial acid number (also partial acid value) describes the quantity of potassium hydroxide that is required for neutralizing all carboxyl-terminated groups and free acids plus half the anhydride groups in an unsaturated polyester resin (UPR). This Application Note describes the determination of the partial acid value by automatic, potentiometric titration according to EN ISO 2114 using KOH in ethanol as titrant.

The total acid number (TAN) indicates the amount of potassium hydroxide required for neutralizing all carboxyl-terminated groups and free acids plus the free anhydride groups in an unsaturated polyester resin (UPR). In this Application Note the TAN determination using automated, potentiometric titration according to EN ISO 2114 using KOH in ethanol as titrant is described.

The hydroxyl number indicates the amount of potassium hydroxide in milligrams required to neutralize the acetic acid taken up on acetylation of 1 g of an unsaturated polyester resin (UPR) containing free hydroxyl groups. In this Application Note the determination of the hydroxyl number by automated, potentiometric titration according to EN ISO 2554 using KOH in methanol as titrant is described.

Polyurethane (PU) is a class of very important polymers due to its flexibility and insulating properties. It is used in various industries such as the automobile industry, in building construction, as well as in the production of synthetic fibers. PU is mostly produced via a chemical reaction between polyisocyanates and polyols. The isocyanate (NCO) content in the raw material is crucial to control its properties. This Application Note shows an easy and straightforward way to determine the NCO content in polyurethane raw materials using a fully automated titration system from Metrohm.

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.

Citrate is used in detergents as a water softener for the prevention of lime deposits. The citrate or citric acid content is therefore an important parameter for the quality control of detergents that can be determined conveniently and precisely using titration with copper sulfate.

Nitrilotriacetate (NTA) is a complexing agent that is used in detergents as a water softener. NTA forms complexes with metal ions such as Ca2+, Cu2+ and Fe3+ and thus prevents the formation of lime and its deposits. The NTA content is therefore an important parameter for the quality of detergents and is determined using back titration of an excess of copper nitrate.

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.

Alkalinity is well-suited as a means of describing the capacity of a body of water to neutralize acid contaminations. It is therefore an important indicator for estimating the influence of contaminations on the ecological system.

The pHe is a measure of acid strength in alcohol fuels and in ethanol. It can be used as predictor of the corrosion potential of an ethanol-based fuel. The determination of the pHe is preferred over the total acidity, because total acidity overestimates the contribution of weak acids (e.g., carbonic acid) and underestimates the contribution of strong acids (e.g., sulfuric acid). Furthermore, the acid strength is an important parameter to determine in order to reduce the risk of failing motors. This Application Note describes the determination of the pHe value using the 913 pH Meter and the EtOH Trode according to ASTM D6423, which covers denatured fuel ethanol and ethanol fuel blends.

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.

Nicotine is a nitrogenous alkaloid that is hazardous to health and is characterized by a very high potential for addiction. The nicotine content in tobacco products must be determined and specified precisely. This Application Note exhibits an easy and straightforward method for nicotine determination in tobacco by non-aqueous titration. Results determined by GC and IC are given as a comparison. In comparison to chromatographic methods, titration is an «absolute method», meaning it is not necessary to calibrate the system prior to the analyses.

The iodine adsorption number (IAN) of carbon black is related to the surface area and can therefore be used for the characterization of carbon black. The presence of volatiles, surface porosity, or extractables will influence the iodine adsorption number. In this Application Note, the fully automated determination of the iodine adsorption number including sample preparation is described.

The hydroxyl number is an important sum parameter for quantifying the presence of hydroxyl groups in a chemical substance. As a key quality parameter, it is regularly determined in various polymers like resins, paints, polyesterols, fats, and solvents. Unlike other standards, EN 4629-2 works pyridine-free and without refluxing at elevated temperatures for a longer time. The determination is based on the catalytic acetylation of the hydroxyl group. It is performed at room temperature, requires only a small sample volumen, and can be fully automated. This Application Note describes the potentiometric determination of the hydroxyl number in 1-octanol and polyethylene glycol according to EN 4629-2. Using the OMNIS DIS-Cover technique, all sample preparation steps can be fully automated. Furthermore, the use of an OMNIS Sample Robot allows parallel analysis of multiple samples. The average time per analysis for one sample is thus reduced from approximately 49 min to 25 min., considerably increasing productivity in the laboratory.

The hydroxyl number is an important sum parameter for quantifying the presence of hydroxyl groups in a chemical substance. As a key quality parameter, it is regularly determined in various polymers like resins, paints, polyesterols, fats and solvents. Unlinke other standards, ASTM E1899 works pyridine-free and without refluxing at elevated temperatures for a longer time. It is performed at room temperature, requires only a small sample size, is applicable to extremely low hydroxyl numbers (<1 mg KOH/g sample) and can be performed fully automatically. This Application Note describes the potentiometric determination of the hydroxyl number in 1-octanol and polyethylene glycol according to ASTM E1899, EN 15168 and DIN 53240-3. Using the OMNIS DIS-Cover technique all sample preparation steps can be fully automated. Moreover, the use of an OMNIS Sample Robot allows parallel analysis of multiple samples. The average time per analysis for one sample is thus reduced from approximately 24 min to 12 min., increasing productivity in the laboratory considerably.

Fully automated determination of the total acid number and total base number in engine oils according to ASTM D664 and ASTM D2896 is possible with the OMNIS Titrator.

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.

Lithium is a soft metal which is used for many applications, such as production of high-temperature lubricants or heat-resistant glass. Furthermore, lithium is used in large quantities in for battery production. It is obtained from brines and high-grade lithium ores. Depending on the lithium concentration, extraction may or may not be economically viable. This Application Note demonstrates a method to determine the lithium concentration in brines by potentiometric titration. Lithium and fluoride precipitate in ethanol as insoluble lithium fluoride. Using ammonium fluoride as the titrant and a fluoride ion-selective electrode (ISE), determination via potentiometric titration is possible. This method is more reliable, faster, and less expensive than the determination of lithium in brine by other more sophisticated techniques such as atomic absorption spectroscopy (AAS).

The pHe value is an indicator for the acid strength and shows the presence of strong acids or bases in ethanol. In Europe, ethanol is used as a blending component in gasoline and needs to have a pHe value between 6.5 and 9.0. This Application Note describes a fast and accurate determination of the pHe value using the EtOH-Trode.

Metformin is one the most commonly used drugs for diabetes type 2 belonging to the group of biguanides. This Application Note describes the determination of metformin hydrochloride assay according to USP using acetic anhydride as solvent.

Quaternary ammonium salts are the active ingredients in fabric softener and require accurate determination to assess the cost and the performance of the fabric softener. This Application Note describes the determination of diamidoamine-based quaternary ammonium salts by potentiometric titration.

Quaternary ammonium salts are the active ingredients in fabric softener and require accurate determination to assess the cost and the performance of the fabric softener. This Application Note describes the determination of dialkyl dimethyl quaternary ammonium salts by back titration.

The bromine number indicates the degree of unsaturation and relies on the simple addition of bromine to the double bonds of alkenes. One mole of bromine is consumed for each mole of carbon-carbon double (C=C) bond present in a substance. In petroleum products, the bromine number corresponds to the olefin content. Normally, chlorinated solvents are used for the determination of the bromine number. In this Application Note they have been replaced by toluene. This makes the determination more ecological. The titration is performed automatically on an OMNIS system in combination with a double Pt-wire electrode. With this setup, a fast and accurate determination by potentiometric titration can be realized.

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.

Compounds with carbonyl groups can be prone to oxidation for which reason their stability often decreases during storage or processing. The method presented here is suitable for the determination of aldehydes and ketones sparingly soluble in water. Samples are dissolved in deionized water. After a reaction with the hydroxylamine hydrochloride at 50 °C, carbonyl groups are quickly and accurately determined by potentiometric titration using the dUnitrode and sodium hydroxide as titrant.

Carbonyl compounds occur in many products such as bio-oils and fuels, solvents, flavors, and mineral oils. Carbonyl compounds are often prone to oxidation and thus their content has an influence on stability during storage or processing. Especially for pyrolysis bio-oils, stability issues are observed during storage, handling, and upgrading. Oils are dissolved in isopropanol. After a reaction with the hydroxylamine hydrochloride at 50 °C, a fast and accurate determination by potentiometric titration using the dSolvotrode and tetra-n-butylammonium hydroxide as titrant is performed.

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.

Esta Nota de Aplicação detalha a determinação da capacidade de neutralização de ácido (ANC) em diversas amostras farmacêuticas em conformidade com os padrões USP<301>.

Penicillin and its related antibiotics are used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, etc. It may also be used to prevent group B streptococcal infection in newborns. The β-lactam ring of penicillin binds to the enzyme DD- transpeptidase, which prevents the formation of cross links during cell wall formation of new bacterial cell, i.e., the division of bacterial cells. USP<425> describes a back-titration method to determine the assay of pharmacopeial penicillin antibiotic drugs and their dosage forms by iodometric titration. The method is illustrated by determining the aminopenicillin content in an ampicillin capsule.

Sulfonamides are drugs used to treat allergies and cough. They also have some antifungal and antimalarial activities. USP<451> describes nitrite titration method for the determination of numerous pharmacopeial sulfonamide drugs and their dosage forms as well as of other pharmacopeial drugs with, for example, hydrazide (e.g., in isoniazid) and amine ester groups (e.g., in procaine) or amide derivatives of amino acids. Here, for illustrating the analysis of the latter, the assay of the diagnostic agent aminohippuric acid is described.

Kjeldahl method is used to determine the nitrogen content in organic and inorganic samples. Kjeldahl consists of three steps: digestion, distillation, and titration. During the catalytic digestion step, organic nitrogen1 is converted into ammonium. Sodium hydroxide is added just before the distillation step for converting ammonium into ammonia. Through steam distillation the latter is transferred into the receiver vessel containing an absorbing agent (e.g., boric acid). Finally, the separated ammonia is titrated against sulfuric acid. Protein content in samples can also be determined from the nitrogen content obtained by Kjeldahl setup. USP<461> describes the titration method to determine nitrogen content in organic products using Kjeldahl nitrogen setup. This Application Note illustrates nitrogen determination in heparin sodium. ______________________ 1Kjeldahl is not working for all nitrogen-containing compounds; nitro and azo groups and nitrogen in rings are not included.

Vitamin C, also known as ascorbic acid or L-ascorbic acid, is an essential nutrient involved in the repair of tissues and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and immune performance, and is also an important antioxidant. This nutrient is found in many foods and is often used as a dietary supplement. USP general chapter <580> describes a titration technique to determine the assay of Vitamin C as ascorbic acid, sodium ascorbate, and calcium ascorbate dehydrate, or their mixture in finished dosage forms as capsules, tablets, and oral suspensions. This Application Note demonstrates the Vitamin C determination in water-soluble vitamin tablets. The methodology can also be applied for oil-soluble vitamin or mineral tablets, as well as oil- and water-soluble vitamin or mineral capsules.

The surface glass test for hydrolytic resistance combined with the glass grains test determines the glass type. The hydrolytic resistance is determined by the quantity of alkali released from the glass under specified conditions. The released alkali is then titrated with hydrochloric acid to a pH value of 5.5.

Anionic surfactants represent, by volume, the most important group of surfactants used in cleaning products. The potentiometric two-phase titration is a universal method for the accurate and fast determination of them. Using the Surfactrode Refill, the anionic surfactants are determined by potentiometric titration with hyamine as titrant.

Denatured fuel ethanol may contain additives such as corrosion inhibitors and detergents as well as contaminants from manufacturing that can affect the acidity of produced ethanol fuel. An increased acid content in solvents could lead to a variety of problems like a shorter storage stability or chemical corrosion. Using the Optrode with phenolphthalein as indicator, the acidity is determined as acetic acid by titration with sodium hydroxide as titrant.

Denatured fuel ethanol may contain additives such as corrosion inhibitors and detergents as well as contaminants from manufacturing that can affect the acidity of produced ethanol fuel. An increased acid content in solvents could lead to a variety of problems like a shorter storage stability or chemical corrosion.Using the dSolvotrode for indication, the acidity is determined as acetic acid by titration with sodium hydroxide as titrant.

Corrosion of metallic components is an inherent problem for engines, because metals naturally tend to oxidize in the presence of water and/or acids. Increased acid content is indicated by a low pH value, and could lead to a variety of problems like a shorter storage life (stability) or a reduced buffer capacity of the used engine coolant or antirust. In this Application Note, engine coolants or antirust samples are dissolved in water, and the pH measurement using the Profitrode is carried out according to ASTM D1287.

Corrosion of metallic components is an inherent problem for engines, because metals naturally tend to oxidize in the presence of water and/or low pH value. The reserve alkalinity of engine coolants and antirusts is a measure of the buffering ability to absorb acidity. The reserve alkalinity is frequently used for quality control during production and often listed in the specifications of the coolants. A fast and accurate determination is therefore important. This Application Note describes the straightforward determination of reserve alkalinity according to ASTM D1121. Using a fully automated system allows an accurate and reliable determination due to the reduction of human errors. Furthermore, the operator is free to carry out other tasks increasing the efficiency of the laboratory.