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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.

The Rancimat method is a widely accepted method for the determination of the oxidation stability of natural fats and oils. Its main application is quality control in oil mills and the oil processing industry. At elevated temperatures and under the exposure of air, fatty acids are oxidized. The reaction products are absorbed in ultrapure water that is continually monitored for conductivity. After an induction period with slow reaction, the formation of volatile carboxylic acids is accelerated. At that time the conductivity begins to increase rapidly. Instead of investing weeks or months, the sample can be oxidized within a few hours.The method can also be used to determine the oxidation stability of solid foodstuffs that contain natural fats or oils. Frequently, a direct determination without extraction of the fat is possible, if the fat content exceeds a minimum level. In these cases, a simple and reliable assessment of the quality of the produced foodstuff is possible.A number of fat-containing solid foodstuffs such as almonds, peanuts, peanut-flavored puffs, potato chips, muffins, butter cookies, French fries, and instant noodles were successfully tested with the Rancimat method. The experiments revealed that the comminution of the sample is one of the most important steps. The grinding procedure of the tested samples was kept as simple as possible to avoid the use of expensive milling instrumentation.

Determination of moisture in lubricating oils with TEOF (triethyl orthoformate).

This Application Note describes the determination of nitrite using thermometric endpoint titration with sulfamic acid. The nitrite content of a solution can be analyzed down to 0.2 mmol/L.

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

The concentration of Al is determined by adsorptive stripping voltammetry at the HMDE. The method is suitable for Al in concentrations in the range of 0.1 ppb to approx. 40 ppb Al3+. Pb2+ ions do not interfere up to a concentration ratio Pb:Al = 10:1. Due to the slow complex formation of Al with solochrome violet RS the measuring solution was heated to 40 °C for 10 min prior to the determination. For standard addition a solution of Al with solochrome violet RS complex was used. All reagents have to be added in the order as listed below.

The present Application Bulletin describes applications that use near-infrared spectroscopy. Each application describes the used and alternatively deployable spectrometer as well as analysis conditions and results and, where available, information on feasibility studies.

This Process Application Note provides a detailed account of the inline assessment of moisture during a pilot scale granulation process using a 2060 The NIR Analyzer.

Determination of fluoride, chloride, bromide, nitrate, sulfate, and iodide in rock leachant using anion chromatography with conductivity detection after chemical suppression.

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.

Determination of iodate, chlorite, bromate, and nitrite using suppressed anion chromatography with UV/VIS detection after post-column reaction.

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.

Determination of nitrite, bromide, nitrate, and iodide in 10 g/L sodium chloride using anion chromatography with UV detection.

Free white paper gives comprehensive overview of how to reliably assess the quality of infant formula with ion chromatography.

If chloride and bromide are present in approximately equal molar concentrations they can be titrated directly with silver nitrate solution after addition of barium acetate. If, however, the molar ratio n(Br-) : n(Cl-) changes from 1 : 1 to 1 : 5, 1 : 10, 5 : 1 or 10 : 1 then greater relative errors must be expected with this method. The Bulletin describes an additional titration method that allows bromide to be determined in the presence of a large excess of chloride. The determination of small chloride concentrations in the presence of a large excess of bromide is not possible by titration.

Near-infrared spectroscopy streamlines ethylene tetrafluoroethylene production by offering rapid, chemical-free analysis of melt flow rate and moisture content.

The present Application Bulletin elucidates several applications for the polymer industry that can be carried out with the aid of NIR instruments. This Bulletin contains analyses of a wide range of parameters in a very large array of samples. The hydroxyl number is one of the best-known of the parameters that can be determined rapidly using near-infrared spectroscopy. The determination of the hydroxyl number in different areas and in different polyol types is also a part of this Bulletin. Each application describes the sample and the instrument that was originally used for the analysis, as well as the recommended instruments and the results.

Determination of bromide and nitrate in 1% sodium chloride solution using anion chromatography with UV/VIS detection (205 nm) after chemical suppression.

Near-infrared spectroscopy is used for a wide range of analyses. Thanks to its fast and non-destructive determination, NIRS is outstandingly suited to quality control of products and raw materials, whether during production or on the finished product. This Application Bulletin shows NIR applications and feasibility studies from the lacquer and paint industry performed using NIRSystems devices.

The present Application Bulletin contains NIR applications for the determination of important parameters for pulp and paper quality analysis. Each application describes the instrument that was originally used for the analysis, as well as the system recommended for the analysis and the results that were achieved thereby.

Near-infrared spectroscopy (NIRS) is a fast, chemical-free alternative analytical technology for caffeine and moisture analysis in roasted coffee beans and grounds.

Near-infrared spectroscopy (NIRS) enables rapid, nondestructive quality control of intact olives, supporting optimal harvest timing and improved oil yield estimation. NIRS provides fast, reagent-free determination of oil content, moisture, and maturity index without sample preparation. Its analytical performance is comparable to established methods such as NMR and Soxhlet extraction, while being significantly faster and easier to implement in mills or quality control laboratories.

Spectroelectrochemistry is a multi-response technique that provides both electrochemical and spectroscopic information about a chemical system in a single experiment, i.e., it offers information from two different points of view. Spectroelectrochemistry focused on the UV/VIS region is one of the most important combinations because this allows us to obtain not only valuable qualitative information, but also outstanding quantitative results. In this application note, the degradation kinetics for 4-nitrophenol, a known pollutant, were determined using SPELEC.

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.

Moisture in cannabis impacts potency and must be accurately determined. Loss on drying (LOD) is the most popular method for determining moisture in cannabis. Unfortunately, this technique is not specific to moisture and the loss of any volatile components, such as terpenes, will be incorrectly classified as moisture. Karl Fischer (KF) titration is the only chemically specific test for moisture. This poster describes the instrument used to determine moisture content by Karl Fischer titration and compares the results of this data to loss on drying.

The quantitative determination of the alkaloid nicotine, which is an essential constituent of the tobacco plant, can be carried out by polarography. The quantification limit is less than 0.1 mg/L in the polarographic vessel.

Determination of traces of nitrite, thiosulfate, and iodide using anion chromatography with amperometric detection at the carbon paste electrode.

NIR spectroscopy enables fast, reagent-free analysis of fat, moisture, protein, fiber, ash, and starch in animal feed, streamlining quality control with no sample prep.

NIR spectroscopy enables fast, reliable analysis of key quality parameters in alfalfa forage (e.g., protein, fiber, and moisture) without any sample preparation.

The increasing popularity of steviol glycosides as low-calorie sweeteners requires standardized analytical methodologies for reliable quality and stability assessment. Moisture content is a critical determinant of rebaudioside M shelf life, and its quantification via oven-based sample preparation coupled with volumetric Karl Fischer titration provides a precise and reproducible approach. Integration with automated systems such as the 874 Oven Sample Processor further enhances analytical throughput and operational efficiency.

NIR spectroscopy offers fast, chemical-free analysis of ash, protein, moisture, and rheological properties in flour – ideal for routine lab or atline quality control.

This Application describes the determination of moisture, nitrogen, and fat in stool samples using near-infrared spectroscopy. These parameters are of great importance in medical diagnostics.

This Application Note demonstrates the data transfer from a Fourier transform to a dispersive NIR instrument, using quality control of lubricating oils as an example application. It is shown that FT-NIR instruments can be replaced by dispersive ones without time-consuming sample remeasurement and subsequent method development.

Near-infrared spectroscopy saves time and resources by simultaneously measuring key quality parameters like lactose, moisture, fat, and protein content in milk powder.

This study shows how a pre-calibrated NIRS instrument is used for multiparameter analysis of several pet food quality indicators like protein, moisture, fat, and ash.

More strict regulations paired with more complex products have increased testing complexity in the paint and coating industry. Therefore, producers ask for more powerful, safe and sustainable analytical methods. Testing by Vis-NIR spectroscopy is a sustainable and costefficient alternative to many wet chemical methods. This white paper describes how Vis-NIR spectroscopy improves testing procedures for various analyses during the formulation and production of paint and coatings in an economic and ecological way.Key words: testing, sustainable, VOC, paint, coating, binders, resins, additives, pigments, solvents

Chemometrics is a powerful tool widely used for method development in the pharmaceutical industry. This whitepaper describes the lifecycle of multivariate models and summarizes the workflow of the development of chemometrical models according to the new USP chapter <1039>.

OMNIS Client/Server boosts business performance with scalable server management, cutting costs by reducing hardware, energy use, and maintenance across locations.

For lubricant analysis, determination of the Acid Number (ASTM D664), viscosity (ASTM D445), moisture content (ASTM D6304), and color number (ASTM D1500) require the use of multiple analytical technologies and, in part, large volumes of chemicals. This application note demonstrates that the XDS RapidLiquid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a fast and cost-efficient alternative for the determination of the AN, viscosity, moisture content, and color number of lubricants. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for multi parameter analysis of lubricants in less than one minute.

Functional group and viscosity analysis (ASTM D789) of polyamides can be a lengthy and challenging process due to the sample’s limited solubility. This application note demonstrates that the DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a cost-efficient and fast solution for a simultaneous determination of the intrinsic viscosity as well as the amine, carboxylic, and moisture content in polyamides. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the analysis of polyamides in less than a minute.

Many fermentation quality parameters can be monitored simultaneously directly in the tank with inline near-infrared spectroscopy, such as the 2060 The NIR Analyzer.

Low sensitivity has limited the use of Raman spectroscopy as a detection method. However, the surface-enhanced Raman scattering (SERS) effect has improved its effectivity for analytical use. Aldehyde dehydrogenase (ALDH) and cytochrome c are analyzed by Raman spectroelectrochemistry as a proof of concept in this Application Note.

Sequential suppression in cation chromatography significantly improves detection limits. The determination of the blank value of the sample vial being used is thus essential for being able to achieve such low detection limits. The leaching tests of various sample vials proceed with the intelligent Preconcentration Technique with Matrix Elimination on the Metrosep C Supp 1 - 250/4.0 column with conductivity detection following sequential suppression. The 50 mL Corning® Cell Culture Flasks from Sigma-Aldrich (CLS430168) exhibit the lowest blank values.

NIRS can simultaneously measure several quality parameters in hops like cohumulone, hop oils, and moisture content, the hop storage index (HSI), and alpha and beta acids.

Alamar Blue is monitored with fluorescence spectroelectrochemistry during its irreversible reduction to resorufin and further reversible reduction to dihydroresorufin.

Determination of key quality parameters of palm oil, namely free fatty acids (FFA), iodine value (IV), moisture content, deterioration of bleachability index (DOBI), and carotene require the use of several different analytical methods, which are laborious and can lack in accuracy. This application note demonstrates that the XDS RapidLiquid Analyzer operating in the visible and near infrared spectral region (Vis-NIR) provides a cost-efficient and fast solution for the determination of these quality control parameters in palm oil. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the analysis of palm oil in less than a minute and can be used by anyone.

Determination of sodium, potassium, DMEA (dimethylethanolamine), calcium, choline, and magnesium in a saline solution using cation chromatography with direct conductivity detection.

This Application Note covers the formation of calcium carbonate from solution.

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.

NIRS simultaneously measures important quality parameters in whey permeate (i.e., ash, phosphate, lactose, protein, pH, and moisture) without any sample preparation.

Improve petrochemical quality control with NIRS. Fast, cost-effective, and no sample prep needed. Learn more in our eBook.

Enhance quality control in material and chemical production with NIRS. Fast, cost-effective, and no sample prep needed. Learn more in our eBook.

This White Paper explores the critical role of advanced online and inline process analysis in brine chlorine operations, emphasizing their advantages over traditional methods.

Stearic acid and stearate derivatives are produced through multistep processing and require monitoring of key quality attributes, including iodine value, acid value, moisture, ash content, melting point, and granulometry. This study demonstrates that near-infrared (NIR) spectroscopy with the OMNIS NIR Analyzer enables rapid, nondestructive quantitative analysis of these parameters for both in-process and final-product samples.

Underestimation of quality control (QC) processes is one of the major factors leading to internal and external product failure, which have been reported to cause a loss of turnover between 10–30%. As a result, many different norms are put in place to support manufacturers with their QC process. However, time to result and the associated costs for chemicals can be quite excessive, leading many companies to implement near-infrared spectroscopy (NIRS) in their QC process. This paper illustrates the potential of NIRS and displays cost saving potentials up to 90%.

Some studies suggest that consumption of the artificial sweetener, aspartame, is correlated with increased risk for brain and hematopoietic cancers, however, others find it to be a safe food additive. Consequently, the US and EU approve aspartame as a multi-purpose sweetener with an acceptable daily intake of 40 mg/kg body weight/day. However, the clear health hazard to individuals suffering from phenlyketonuria and ongoing criticism by health food advocates continues to fuel the challenge against aspartame’s widespread use in the food industry.Using Misa (Metrohm Instant SERS Analyzer), beverage products are screened for aspartame levels with no sample preparation beyond simple dilution of a consumer product.

Automated online analysis with the 2060 TI Ex Proof Process Analyzer facilitates constant monitoring of the crude oil desalting process according to ASTM D3230.

Ion chromatography (IC) provides an automated, fast, and sensitive solution to accurately quantify cationic and anionic components including acetate simultaneously. This comprehensive approach makes IC an economic alternative to traditional techniques for the quality control of pharmaceutical solutions like haemodialysis concentrates. Ease-of use, accuracy, and the high-throughput of IC increase productivity and comply with the demands of modern routine and research labs.

Potassium ferrocyanide (KFC) is an anti-caking compound added to table salt. Although this is a common non-toxic food additive, its spectroscopic response is representative of analogous cyanide compounds. Trace detection of other cyanides in food products is essential to the safety of consumers, as they can be toxic at oral consumption levels as low as 20 μg/g.This application demonstrates rapid trace analysis of potassium ferrocyanide in table salt with Misa (Metrohm Instant SERS Analyzer), in a simple assay format with minimal use of laboratory reagents.

An ion chromatography (IC) assay with suppressed conductivity detection is the standardized way to accurately quantify phosphate in phosphates compounded injections.

Compounded injections of sodium bicarbonate are sterile solutions for correcting metabolic acidosis and other conditions requiring systemic alkalinization. Compounded injections of sodium phosphates serve as a phosphate source to either prevent or correct hypophosphatemia in patients with restricted oral intake. Ion chromatography (IC) with suppressed conductivity detection is the standardized way to accurately quantify sodium in these solutions.

NIRS enables rapid, chemical-free analysis of glucose, fructose, sucrose, and Brix in fruit juices without sample prep, offering a fast alternative to traditional methods.

Brilliant Blue (BB) FCF, more commonly known as FD&C Blue #1, is the most commonly used blue dye worldwide for food and beverages. It is generally accepted as safe and non-toxic. Aside from foods labelled as organic or as free from artificial dyes, there is little objection to the use of BB at levels at or exceeding 100 μg/g in foods.This application for Misa (Metrohm Instant SERS Analyzer) is unique. The benefit is twofold — successful detection of a fluorescent dye, and a unique sample cleanup technique that permits detection of a target that does not exhibit a strong SERS signal and is present in a complex matrix. While Misa successfully detects BB in direct sampling, this application describes a simple extraction method that improves detectability of BB with Misa.

With MISA and MIRA, easy-to-use test kits and flexible sampling allow rapid and accurate interrogation of suspect materials with minimal time, training, and expense.

The iodometric back titration is a precise method used to accurately measure the caffeine content in various aqueous samples. Reliable determinations are made easy using the OMNIS Titrator equipped with a dPt Titrode.

Metrohm’s MIRA XTR handheld Raman spectrometer enables fast, reagent-free identification of phosphate species, enabling continuous monitoring of dynamic systems.

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.

The Bayer Process is the method used to refine alumina from bauxite ore, as smelting aluminum directly from alumina is much more cost- and energy-effective. In this process, "aluminate liquors" are created by digesting the crushed bauxite with CaO and NaOH at high temperatures. Additionally, the CaO causticizes carbonate which forms in the alkaline solution from organic degradation and CO2 absorption from the atmosphere. Contaminations are removed at various steps in the process, and the liquor is filtered from the alumina crystals before it is recycled back to the digestion step. Before the spent liquor can be reused, a determination of the concentrations of the total hydroxyl (“caustic”), carbonate, and alumina values is required. These parameters can be determined quickly via thermometric titration with the 2035 Process Analyzer.

Organic halides must be monitored in the environment. Combustion ion chromatography (CIC) is used for accurate halogen analysis in solids following EN 17813:2023.

Within the scope of the USP monograph modernization, potassium is determined in potassium bicarbonate effervescent tablets for oral suspension applying cation chromatography with direct conductivity detection. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). All acceptance criteria are fulfilled.

In the Solvay process, ammonium hydrogen carbonate and table salt are converted to sodium hydrogen carbonate and ammonium chloride. Heating the former yields sodium carbonate (soda), an important raw material for the soap and glass industries. Ammonia is an incipient and is regenerated almost completely through conversion of the ammonium chloride with lime milk (Ca(OH)2).A Metrohm process analyzer monitors the ammonia content in the saturated table salt solution after absorption tower, thus guaranteeing a good product yield in the carbonization tower. Additional parameters which can be determined with the analyzer in the Solvay process include: alkalinity, carbonate, chloride, calcium oxide and carbon dioxide.

Auramine O (AO) is an industrial dye used for a broad range of manufactured products and as a fluorescent stain for detecting acid-fast bacteria in clinical specimens. Due to its intense yellow coloration, AO is also prized as an additive for enhancing the visual appeal of illicitly processed food products. Despite bans on AO as a food additive, surveillance testing indicates its persistent use as an adulterant in foods and spices.Misa (Metrohm Instant SERS Analyzer) achieves the rapid and sensitive detection of AO in curry powder in a simple assay format.

Paraquat is a highly effective, yet exceptionally toxic herbicide used to manage weeds in agricultural operations. In recognition of paraquat’s danger, the EU and several other countries have banned its use for any application, though the US EPA permits its limited use by licensed applicators. Despite tight regulation, paraquat continues to be produced and is liberally used as an herbicide in over 100 countries without regulatory oversight.Testing for paraquat typically requires involved sample processing and analysis by trained chemists using expensive laboratory instruments such as HPLC, CE, and LC/MS. Misa achieves trace level detection of paraquat residue in tea leaves in a fully integrated, portable, smart system for easy on-site testing by non-technicians.

As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium and sodium content in potassium and sodium bicarbonates and citric acid effervescent tablets for oral solution. The present IC method has been validated according to USP General Chapter <621>.

This application focuses on the simultaneous analysis of cations and suppressed anions with a dual channel Metrohm IC operated by OpenLab CDS.

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 basic chemicals industry is responsible for producing thousands of raw materials at very large scales. The industries downstream rely upon a certain level of chemical purity to manufacture their own goods, as certain impurities can cause major issues in various processes. During the production of the basic chemicals NaOH and KOH, electrolysis of saturated brine solutions with membrane-cells yield the product which is further concentrated by evaporation. Impurities from the salts used in the brine will also be concentrated. Typically, this impurity analysis is performed offline with various hazardous chemicals with varying shelf-lives. The Process Ion Chromatograph is able to perform the measurement described in ASTM E1787-16 online, ensuring quality product without the need for time-consuming, hazardous laboratory experiments.

Ion chromatography (IC) with suppressed conductivity detection has been approved by the U.S. Pharmacopeia (USP) as a validated method to quantify the monofluorophosphate (MFP) content in sodium monofluorophosphate. This Application Note shows that all acceptance criteria for the USP Monograph «Sodium Monofluorophosphate» are fulfilled and the procedure was approved as a validated USP method.

Monitoring Sb(III) stabilizer levels during electroless Ni plating is critical for high-quality coatings. Anodic stripping voltammetry offers fast, reliable Sb(III) analysis.

Electroless Ni plating offers superior surface finish and corrosion resistance. Anodic stripping voltammetry allows Bi stabilizer to be monitored in Ni plating baths.

Sodium fluoride tablets for pharmaceutical use need to comply with U.S. Pharmacopeia (USP) requirements. Ion chromatography (IC) with suppressed conductivity detection has been approved by the USP as a validated method to quantify fluoride content in sodium fluoride tablets. In the course of the USP monograph modernization, using automated IC makes this type of analysis even easier.

Potash is commonly mined from ore, deposited after ancient inland oceans evaporated. The potassium salt is then purified in evaporation ponds. At the end of this process, the potash is typically obtained as potassium chloride. Potash is mainly used as fertilizer, providing potassium—an essential nutrient—to plants. Additionally, it is used in the chemical industry and to produce medicine. Potassium content in potash is typically determined by flame photometry (F-AES) or ICP-OES. However, these techniques have high investment and running costs. By applying the historically used gravimetric precipitation reaction as a thermometric titration, it becomes possible to rapidly and inexpensively determine the potassium content in potash within minutes.

This Application Note offers an easy way to determine the ammonia content in cacao nibs by using ion measurement, applying the standard addition technique in a reliable cost- and time-saving manner.

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.

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.

If consumed in excess, sodium may damage the cardiovascular system. It is therefore in the interest of food manufacturers to reduce the salt content and while preserving the flavor of the food.To ensure consistent quality, it is critical to know the exact salt content in the raw materials and the final products. This is only possible by performing precise measurements during the production process.This Application Note explains the determination of sodium chloride in dough and bread quickly according to AOAC 971.27 with the Eco Titrator equipped with an Ag Titrode.

Fertilizers are applied in the agricultural sector to provide more essential nutrients to growing plants. The so-called «NPK» fertilizers provide such nutrients to plants with its three main components (N – nitrogen, P – phosphorous, K – potassium). In fertilizers, nitrogen is mainly provided in three forms: as ammonium nitrate (NH4NO3), ammonia (NH3), and urea (H2NCONH2). Determination of the individual nitrogen-contributing components is often laborious work. Thermometric titration offers the possibility to rapidly determine the amount of ammoniacal nitrogen and urea nitrogen in a single titration using sodium hypochlorite as titrant.

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.

Safe and fast ethanol determination in hand sanitizers is possible with reagent-free near-infrared spectroscopy (NIRS). NIRS provides reliable results in a few seconds, quickly indicating when adjustments in formulation are necessary.

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.

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.

The amine value is an important parameter and quality indicator to determine in chemical processes and pharmaceuticals. This Application Note presents the nonaqueous perchloric acid titration of triethanolamine.

Carbendazim (MBC) is a common fungicide approved for regulated use in agriculture globally, outside of the EU. Most MBC is found on fruits as surface contamination, the result of sprays applied prior to harvest. The US EPA has determined that a concentrations below 80 μg/mL in orange juice are not a health risk, while the EU restricts MBC levels to 10 ng/g (from imported produce) in foods intended for baby food production.This Application Note describes a very simple test for surface MBC and provides library spectra demonstrating the sensitive detection of MBC with Misa (Metrohm Instant SERS Analyzer).

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.

The OMNIS Titrator equipped with a Pt Titrode accurately and reliably determines titer concentration even in diluted titrants as shown in this Application Note.

Adulteration in the food industry is a significant concern due to potential health risks and changes in product quality and nutrition. Detecting such adulteration is challenging, however, to ensure high-quality products, precise measurements during the manufacturing process are essential for identifying any contamination in raw materials and final products. This Process Application Note details the inline analysis of potato starch in the wheat flour manufacturing process with a 2060 The NIR Analyzer from Metrohm Process Analytics.

Rhodamine B is a dye utilized extensively in biotechnology and industrial applications and is one of several colorants banned for use as food additives in Europe and North America. The most common analytical methods for detection of illicit dyes in food products, GC/MS and HPLC, are laboratory-based instrumental methods that require specialized training.With Misa (Metrohm Instant SERS Analyzer), detection of trace amounts of Rhodamine B in ground cayenne pepper is quick and easy after a facile extraction procedure with minimal material consumption. Rhodamine B can be detected in cayenne powder at a concentrations as low as 10 µg/g.

Metanil yellow (MY) is an azo dye used in the manufacture of external-use products such as textiles; however, it is prohibited from use as a food additive in many countries. Toxicology studies demonstrate that ingestion of MY results in significant neurological and multi-organ damage. Despite these hazards, MY is commonly used as an illicit colorant for enhancing the visual appeal of spices and legumes, most notably turmeric. Ideal tests for such food adulterants feature methods that are selective and sensitive, yet portable and convenient.Misa (Metrohm Instant SERS Analyzer) achieves rapid and accurate detection of MY in a facile assay format.

Erythrosine B (EB), also known as Red Dye #3, is a synthetic dye approved for use in candy in the US, and in pharmaceuticals and cosmetics in the EU and elsewhere. However, rodent studies suggest that ingestion of EB can promote thyroid tumor formation. EB may also be implicated as a dietary factor contributing to hyperkinesis in children. WHO recommends a daily intake of EB less than 0.1 mg/kg of body weight.The ability to obtain fast results with a portable test platform recommends Misa (Metrohm Instant SERS Analyzer) as a competitive and cost-effective alternative to laboratory technologies (e.g., CE, HPLC) currently employed for detecting EB in foodstuffs.

Anticavity pharmaceuticals like sodium fluoride and acidulated phosphate topical solution products require strict quality control. This Application Note outlines the fluoride IC assay as described in the USP Monograph Sodium Fluoride and Acidulated Phosphate Topical Solution.

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.

This Application Note details the determination of acid-neutralizing capacity (ANC) in several pharmaceutical samples in compliance with USP<301> standards.

As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium content in potassium bicarbonate and potassium chloride effervescent tablets for oral solution. The Metrosep C 6 - 150/4.0 column (L76) provides the required separation of potassium and magnesium. The present IC method has been validated according to USP General Chapter <621>.

This Application Note describes carbonate determination with ion chromatography in a 50% sodium hydroxide solution. Sodium hydroxide solutions form carbonates through the absorption of carbon dioxide from ambient air. The carbonate content of an NaOH solution is determined using ion-exclusion chromatography with subsequent conductivity detection following inverse suppression. The samples are diluted 1:20 prior to the analysis and – in order to prevent CO2 absorption – stored in closed sample vessels.

Permanganate absorption number (PAN) analysis per ISO 8660 ensures caprolactam purity, a precursor of Nylon 6. This application describes real-time, continuous PAN monitoring.

Thiabendazole (TBZ) is a broad-spectrum pesticide used both as a fungicide in fruits and vegetables and for controlling parasites in animal feed. To ensure consumer safety, regulatory agencies establish maximum residue levels (MRL) for pesticide-treated crops based on their review of risk assessment studies. For bananas, which are either aerially sprayed or dipped in protectant solutions of TBZ, the US FDA reports a MRL of 3 μg/g, and the EU stipulates a MRL of 6 μg/g by weight.With Misa (Metrohm Instant SERS Analyzer), the rapid and sensitive detection of TBZ on bananas is demonstrated in formats easily adapted for food safety surveillance testing.

The content of organic matter, limestone, silt, clay, and sand, along with pH value and exchangeable calcium and magnesium in soil can be determined in seconds with NIRS.

Online mercaptan and H₂S monitoring with the 2060 TI Ex Proof Analyzer certified for Zone-1 and Zone-2 areas.

Fenthion is a multi-purpose insecticide used in many countries for mosquito control. To minimize human exposure and the unintentional poisoning of wildlife, the US EPA has classified fenthion as a restricted-use insecticide. However, the widespread spraying of olive orchards in Mediterranean countries results in olive oils that occasionally exceed the maximum residue limits established for olives.Misa (Metrohm Instant SERS Analyzer) easily achieves sensitive trace detection of fenthion in spiked olive oil after a simple organic solvent extraction. This Application Note presents an excellent example of how the signal from SERS substrates can compete with the target signal at very low levels of detection.

Sodium fluoride gel for pharmaceutical use needs to comply with USP requirements. The actual monograph (USP 42) uses two different methods for the identification and the assay. Ion chromatography allows the analysis of these two parameters in one single determination. In the course of the USP monograph modernization, this ion chromatographic approach makes this type of analysis even easier.

Portable Raman is used to quantify trigonelline, an alkaloid that contributes to the health benefits of some foods. A simple method to quantify the presence of diluted trigonelline in solutions using surface enhanced Raman spectroscopy is described. Portable Raman is a tool that could be used in quality control of food items such as coffee and quinoa.

Potassium citrate and citric acid oral solutions act as systemic alkalizers. Potassium assays, validated per USP <621> and <1225>, use IC with L76 cation-exchange columns.

The assay of calcium acetate, often used as a phosphate binder for dialysis patients, can be performed with ion chromatography (IC) as per USP <621> and <1225>.

Calcium carbonate has a wide applicability in the pharmaceutical industry as an excipient and also as an active ingredient, and in the food industry as a major dietary supplement. The U.S. Pharmacopoeia (USP) monographs for calcium and magnesium carbonates tablets as well as calcium carbonate and magnesia chewable tablets currently describe manual titration as the assay procedure for calcium and magnesium. The USP has embarked on a global initiative to modernize many of the existing monographs across all compendia. In response to this initiative, two alternative analytical methods were developed to determine the analytes calcium and magnesium. This Application Note presents ion chromatography (IC) procedures using conductivity detection that provide better accuracy and specificity and are suitable for the intended purpose. These validated IC methods (according to USP General Chapter <1225>) offer a significant improvement to the existing assays because they can simultaneously determine both analytes calcium and magnesium, saving both time and effort.

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

Thermometric titration is presented as a simple, fast, and reliable method to determine calcium content in various drilling fluids.

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 Process Application Note describes a method to determine the strontium and barium concentration in brine as early detectors ofmembrane fouling via online process ion chromatography. Using this multiparameter analytical technique can help reduce the risk of premature membrane fouling and avoid unexpected maintenance and high utility costs with 24/7 automated analysis.

This Application Note shows that the parameter of surface basicity of zeolites can be measured by thermometric titration.

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

This Application Note explains manual and automated iR drop correction with electrochemical impedance spectroscopy and cautions against using less accurate methods.

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.

Monitoring the range of organic acids in wine is crucial to improve flavor and quality, and to fulfill universal standardized criteria such as the International Code of Oenological Practices. Analytically, organic acids can be properly determined with ion chromatography (IC) and suppressed conductivity detection. As a multicomponent method, inorganic acids can also be resolved which are also valuable tracers for wine quality and taste. This Application Note presents two IC methods for wine quality analysis: a fast isocratic screening method of major organic acids and anions including sulfite, and a complex monitoring method with a binary gradient to separate 15 organic acids. Inline Ultrafiltration was used for economical sample treatment.

Free White Paper outlines the fundamental principles of the nitrogen reduction reaction. It then delves into the technical barriers hindering the industrialization of green ammonia production, their impact on final yield and selectivity, and potential strategies or research gaps to overcome these issues.

This document outlines Rancimat testing for both liquid and solid food samples, including direct and PEG methods, for oxidation stability QC in the food industry.

Iodide contamination in glacial acetic acid poses risks for downstream processes. Cathodic stripping voltammetry (CSV) at the HMDE offers reliable iodide measurement.

This polarographic method uses the Multi-Mode Electrode Pro for simultaneous detection of carbonyl impurities in alcohols, ensuring high product quality and stability.

Efficiently analyze food products with ion chromatography (IC). Discover its robust applications in quality control for beverages, food additives, and dairy.

Direct titration is a simple and precise way to accurately measure the caffeine content in different nonaqueous products. The OMNIS Titrator equipped with a dSolvotrode reliably determines caffeine through flexible analyses combined with high-end software.

It is crucial to monitor iodide in NaCl brine to prevent membrane fouling during chlor-alkali electrolysis. Stripping voltammetry offers precise iodide analysis.

Worldwide, milk and dairy products are vital sources for human nutrition. A major component and energy source in dairy products is lactose. To efficiently metabolize lactose, the enzyme lactase is indispensable. However, globally nearly 70% of the population is lactose intolerant and they have difficulties to digest lactose. Lactose malabsorption leads to numerous gastrointestinal and extra-intestinal symptoms and other complaints with varying extents. Therefore, consumers rely on accurate food labels and for manufacturers appropriate sensitive analytical techniques are a must to comply with these demands. Ion chromatography with pulsed amperometric detection (IC-PAD) enables the determination of very low lactose contents. Validation according to AOAC requirements shows the high sensitivity and reliability of this method as a routine analysis.

Electrochemical Raman (EC-Raman) spectroscopy enhances comprehension of energy storage devices by tracking physicochemical changes. This note details EC-Raman findings during nickel-metal hydride (NiMH) battery charge and discharge simulations.

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.

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.

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.

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.

The pH value in carbon black, an essential additive in modern lithium-ion batteries, is accurately and reliably analyzed in this Application Note by using the 913 pH Meter equipped with a Unitrode easyClean according to ASTM D1512 as well as ISO 787-9 and GB/T 1717-1986.

This study presents the automatic titration of low sulfite levels in beet crystal sugar using an OMNIS Titrator and a Pt Titrode as the potentiometric sensor.

The Rancimat method determines the oxidation stability (OSI) and antioxidant capacity (SI) of solid foods. OSI measurements are performed directly, with extracted isolated fat, or via the polyethylene glycol method. SI can be determined when the sample is mixed with a reference of antioxidant-free fat.

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.

Iron sucrose injections are used during the treatment of iron deficiency anemia. They contain a mixture of ferric iron (Fe3+) and ferrous iron (Fe2+). Ferrous iron content may be determined by subtracting the ferric iron content from the total determined iron content. Yet, this increases the measurement error due to error propagation. Alternative determination of iron(II) with cerium(IV) by potentiometric titration may be hampered, as the equivalence point cannot be determined unequivocally. Determination by thermometric titration is a more robust and therefore more reliable alternative, as this method is unaffected by the sample matrix. Here, the endpoint of the titration is indicated by a fast responding thermometric sensor. Endpoint detection is further improved by spiking the sample with 0.2% ammonium iron(II) sulfate (FAS), increasing the reliability of the determination. Compared to potentiometric titration, thermometric titration is faster and more convenient as no sensor maintenance is required. One determination takes about 2–3 minutes.

Dissolved oxygen (DO) is generally considered detrimental to wine quality, especially if introduced after fermentation, storage, or bottling. The presence of oxygen after primary fermentation and during the later stages of winemaking can enhance browning reactions, chemical and microbiological instability, and the formation of off-flavors such as acetaldehyde. Knowing the DO content in wine is important through the entire wine production process, because oxidation is a common fault in bottled wines. With the 913 pH/DO meter and the 914 pH/DO/Conductometer, the oxygen content of wine can be determined quickly and easily directly on site.

This Application Note demonstrates how the OMNIS NIR Analyzer Solid quickly determines the cotton content in various textile products within just 30 seconds.

Lithium salts (e.g., lithium carbonate and lithium hydroxide) are used in myriad applications. Lithium hydroxide is used for the production of lithium stearate, an important engine lubricant. In addition, it is utilized as an air purifier due to its ability to bind carbon dioxide. While the majority of lithium carbonate is used for aluminum production, it is also used for the glass and ceramic industry. It lowers the melting point of these materials, lowering the associated electricity costs and making it cheaper to produce them.For all of these applications, it is important to know the quality of the pure lithium salts used in the various production processes. This Application Note presents an easy method for the assay of lithium hydroxide and lithium carbonate on an automated OMNIS system.

This Application Note presents a complementary method that allows a consecutive determination after the sample preparation (digestion) of both metal ions in one beaker with an optical sensor and xylenol orange as an indicator.

Hydrochloric acid is a strong, inorganic mineral acid with great significance in the chemical industry. The potentiometric titration of hydrochloric acid with sodium hydroxide is one of the most important and also most frequent analyses performed in the laboratory. In this Application Note, an acid-base titration is presented where the concentration of HCl is determined with NaOH using a pH electrode with an integrated Pt1000 temperature senor for the most accurate results

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.

Here, the most common circuit elements for EIS are introduced which may be assembled in different configurations to obtain equivalent circuits used for data analysis.

Dissolved oxygen (DO), incorporated into juices during processing, affects quality parameters of the beverage during storage such as Vitamin C concentration, color, and aroma. Various oxygen removal methods are used during juice production, such as vacuum-deaeration or gas sparging to increase product quality and extend shelf life. However, these methods have the drawback that the aroma might be affected since the volatile compounds are also removed. By assessing the DO content in fruit juices, manufacturers can improve the overall product quality. This application note describes a fast and accurate determination of dissolved oxygen in juices by using an optical sensor.

In the food industry, it is essential to determine and monitor certain quality parameters to guarantee consistency. This is especially important for liquid dairy products, which are subject to a strict cold chain. Both the dissolved oxygen (DO) and the pH value have proven to be reliable quality criteria. Oxygen shortens the shelf life and influences the product quality (e.g., nutritional value, color, and flavor). The DO content depends on the salinity in the sample, which is automatically calculated and corrected by the 914 pH/DO/Conductometer during the parallel conductivity measurement. Acidity is another important characteristic to measure that can be checked easily using the pH value. With the 914 pH/DO/Conductometer, all important quality criteria can be monitored with one device.

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 vaping and electronic cigarette industries have grown impressively in the past decade. The mixtures used in these products are usually called «e-liquid», «e-fluid», or «e-juice». To ensure the quality of these e-liquids, testing the most important quality parameters, such as nicotine content, is required. Nicotine in tobacco is usually determined by gas chromatography or liquid chromatography. Aqueous acid base titration is a much more affordable alternative for this determination. As e-liquids do not contain other components which might interfere with the titration, the aqueous acid base titration presented in this Application Note can be applied for nicotine determination. This method is an affordable and reliable way to determine the nicotine content in e-liquids and their nicotine starting material, ensuring the quality of these products.

Phosphoric acid is a triprotic inorganic acid used for many purposes: as a raw material for the production of phosphate fertilizers, detergents, as an electrolyte in phosphoric acid fuel cells, rust removers, and for the passivation of iron and zinc to protect against corrosion. This Application Note presents an acid-base titration where the concentration of phosphoric acid is determined over all three of its dissociable protons by titrating it with sodium hydroxide.

This application presents the fully automated determination of acidity in jet fuel as per ASTM D3242 via photometric titration with an automatic titrator and the Optrode.

This Application Note describes the determination of the oxidation stability of different sausages with the recommended method from Metrohm using an 892 Professional Rancimat.

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.

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 nitrogen 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 describes the titration method to determine nitrogen content in organic products using Kjeldahl nitrogen setup. This Application Note illustrates nitrogen determination in heparin sodium.

Electroplating processes are used in several different industry sectors to protect the surface quality of various products against corrosion or abrasion and significantly improve their working life. It is essential to check the bath composition on a regular basis to ensure that the process is operating correctly. Typical examples of electroplating baths include alkaline degreasing baths or acidic or alkaline baths containing metals e.g. copper, nickel, or chromium, or components like chloride and cyanide. It is crucial that the chosen analysis technique fulfills high safety standards for these kinds of analyses and produces reliable results. The OMNIS Sample Robot system automatically pipettes and analyzes aggressive electroplating bath samples on different workstations, increasing the safety in the lab. This provides more reliable results in comparison to manual titration and is more time efficient as different parameters can be analyzed in parallel.

Accurate, reliable determination of ionic surfactants with the Epton two-phase titration method can be achieved using an OMNIS system as shown in this study.

NIR spectroscopy measures ice cream quality parameters like total solids, fat content, lactose, protein percentage, sucrose content, and calories in seconds.

Acid throwing, a historical method for retribution against women, has become a modern threat of a different nature. Concentrated acids and other corrosive substances have emerged as modern tools of social violence. Aggressors use common plastic containers with openings that create a powerful directional spray, such as lemon juice squeeze bottles. Sulfuric and phosphoric acids were chosen for analysis here due to their highly corrosive nature- acid attacks in London most commonly use sulfuric, phosphoric, and nitric acids.2017 saw a remarkable number of acid attacks in the UK, with reported incidences averaging 2x a day. Detection and regulation of acids may contribute to prevention of this social scourge.

Thiram is used extensively as a fungicide and parasiticide to prevent disease in crops and as an animal repellent to protect trees and ornamental plants. However, extensive toxicological studies conclude that chronic, high-level exposure can cause considerable organ damage to land and aquatic species. The US defines maximum residue limits that vary for different food crops. In contrast, the EU recently banned thiram and is moving to use pesticides that carry reduced health risks.Using Misa (Metrohm Instant SERS Analyzer), low level detection of thiram on apples is achieved with guided workflows adapted for use by diverse testers.

In order to consistently manufacture high quality baked goods, it is critical to measure the pH value and acidity content in the raw materials and during the production steps. These factors have a major influence on the taste and storage lifetime of the final product. Consistent product quality is only possible with precise measurements during the process.This Application Note describes the measurement of pH value and the total titratable acidity in flour, dough, and bread using the Eco Titrator from Metrohm.

This Application Note describes the determination of the oxidation stability of the fat in different sausages extracted with cold petroleum ether using an 892 Professional Rancimat.

Pyrimethanil is a broad-spectrum fungicide. As grapevines are susceptible to fungal pathogens, large-scale viticulture operations apply pyrimethanil as part of a mixed treatment. Although chemical analysis of wines post-fermentation finds low to undetectable amounts of residue, pyrimethanil is a suspected human carcinogen. The US FDA and EU have therefore established a maximum permissible level of 5 μg/mL pyrimethanil in finished wine products.In this application, trace detection of pyrimethanil in wine with Misa (Metrohm Instant SERS Analyzer) requires few laboratory supplies and minimal sample processing, yet returns rapid results.

Malathion is an insecticide widely used on a broad spectrum of plant species. Several studies have implicated chronic exposure to malathion in the development of certain cancers. Maximum residue limits for malathion have been enacted by the regulatory agencies of several countries: the US Food and Drug Administration sets maximum residue limits at 8 μg/g in foods, while the EU has a considerably more stringent limit of 20 ng/g.SERS is an accepted method for detection of malathion on fruit and vegetable surfaces. Misa (Metrohm Instant SERS Analyzer), which requires minimal laboratory chemicals and consumables and provides an extremely user-friendly interface, is an excellent SERS solution for trace detection of food adulterants.

The standardization of the cationic surfactant TEGOtrant is performed using potentiometric titration as well as near-infrared spectroscopy (NIRS) in this application.

Methanol, often present in spirits prepared with industrial solvents like wood alcohol, can lead to blindness and even death when ingested. After an incident involving methanol-laced alcohol in the Czech Republic, they adopted Raman spectroscopy as the preferred method for identifying and quantifying methanol in contaminated spirits, following an exhaustive study using various screening tools. This Application Note discusses the reasons why Raman spectroscopy is the ideal choice for this application and shows a real-world example of Raman analysis of methanol-laced rum.

Diphenylamine (DPA) is used as a dye fixative and antioxidant in industrial applications and as a produce preservative in agricultural operations. Food safety advocates are concerned that daily ingestion of DPA, particularly in foods meant for babies, could have negative effects on children’s health. To mitigate potentially toxic effects of DPA, both the US and EU stipulate a maximum residue limit (MRL) of 5 μg/g for whole pears and a stringent MRL of 10 ng/g for all processed baby foods.Misa (Metrohm Instant SERS Analyzer) provides a user-friendly and cost-effective alternative to traditional analytical methods used for detecting DPA in foods, such as GC-MS and GC-NPD.

Raman spectroscopy is ideally suited to rapidly screen for methanol contamination in spirits.

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).

In this Application Note, hydrogen permeation experiments are conducted following the procedure described in the ASTM standard G148.

This Application Note presents an electrochemiluminescence (ECL) method for a fast, accessible, and cost-effective alternative method to detect fentanyl.

Operando Raman spectroelectrochemistry shows the potential-dependent structural evolution of Ni-based oxygen evolution catalysts, directly linking vibrational signatures to catalytic activity. Correlating these spectroscopic markers with electrochemical performance not only clarifies OER (oxygen evolution reaction) mechanisms but also guides the design of Ni-based catalysts for related oxidation reactions.

Currently, there are no simple tests to identify counterfeit beer. This Application Note demonstrates the ability of i-Raman EX, the B&W Tek Laboratory Raman instrument with a 1064 nm laser, with principal component analysis (PCA) to distinguish between beers from different brewers and from a mixture of beers.

Potassium chloride and potassium bicarbonate effervescent tablets are used to prevent potassium deficiency. Pharmaceutical manufacturers and labs adhere to strict quality regulations using USP-NF monographs. Ion chromatography with suppressed conductivity detection, utilizing the Metrosep A Supp 16 - 100/4.0 (L91) column, is approved by the USP to quantify chloride content in these tablets, following validation per USP General Chapter <621>.

Manufacturers and laboratories must use validated methods to determine the zinc content in skin care products and pharmaceutical supplements to meet strict quality standards set by the United States Pharmacopeia and National Formulary (USP-NF). USP-NF has updated the zinc monograph (General Chapter <591>, Zinc Determination) and replaced the existing identification procedure of titration with ion chromatography (IC). The analysis involves separating Zn using a Metrosep A Supp 10 column followed by post-column reaction using 4-(2-pyridylazo)resorcinol and detection at 530 nm.

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.

Monitoring hydrogen peroxide content online in the HP-PO production process requires a rugged explosion-proof solution like the 2060 TI Ex Proof Process Analyzer.

Lithium is a soft alkali metal that is typically obtained from salt lake brines. Lithium is used for many applications, but especially for production of lithium-ion batteries in electric cars, mobile phones, and more. This Process Application Note presents a method to monitor lithium as well as other cations in brines by online process ion chromatography (IC), a multiparameter analytical technique that can measure ionic analytes in a wide range of concentrations.

Processing degrades antioxidant levels in spices. The 892 Professional Rancimat determines oxidation stability with the PEG method as per AOCS Cd 12b-92 and ISO 6886.

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>.

This Application Note evaluates corrosion in Type 430 stainless steel according to ASTM G5 with VIONIC powered by INTELLO and an ASTM-compliant corrosion cell setup.

This Process Application Note presents a method to accurately monitor lactic acid and glucose inside a bioreactor in «real-time» with the 2060 Raman Analyzer from Metrohm Process Analytics.

Raman spectroscopy offers a fast, nondestructive way to identify microorganisms and analyze metabolites directly from culture media, without complex genetic sequencing.

Dental care products often contain sodium fluoride as an active ingredient. Manufacturers use the United States Pharmacopeia and National Formulary (USP-NF) Monograph «Sodium Fluoride» to quantify sodium fluoride and its anionic contaminants chloride and acetate in these products. The validated USP method proposes ion chromatography (IC) with suppressed conductivity detection to carry out the fluoride assay as well as the impurity determination in a single chromatogram.

Raman spectroscopy is used for material characterization by analyzing molecular or crystal symmetrical vibrations and rotations that are excited by a laser, and exhibit vibrations specific to the molecular bonds and crystal arrangements in the molecules. Raman technology is a valuable tool in distinguishing different polymorphs. Examples of portable Raman spectroscopy for identification of polymorphs and in monitoring the polymorphic transiton of citric acid and its hydrated form are presented.

Iodine is an essential mineral for human health, where it is necessary for e.g., the production of thyroid hormones. The presented method describes the determination of free iodide in milk samples using Metrohm Low Volume Inline Dialysis for automated sample preparation prior to injection into an ion chromatograph (IC) and subsequent amperometric detection in direct current (DC) mode.

This Process Application Note is dedicated to the online analysis of zinc, iron and sulfuric acid in several stages of the zinc production process. Additionally, traces of germanium, antimony, as well as several transition metals (e.g., Ni, Co, Cu, Cd) can be precisely determined (<50 µg/L) in the purification filtrates and reactor trains.

Online acid number analysis in various oil products is possible with thermometric catalytic titration according to ASTM D8045 using the 2060 TI Ex Proof Process Analyzer.

As an alternative to titration, ion chromatography (IC) with suppressed conductivity detection has been approved by USP as validated method to quantify chloride content in NaCl tablets for solution or oral use.

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.

Application: Free and total carbohydrate determination in instant coffee with IC-PAD according to AOAC 996.04 and ISO 11292.

This Application Note presents an update to the standard AOAC method for total GOS determination in foodstuffs.

Nitrite and nitrate salts are used as preservatives for meat and meat products. Nitrate salts (labeled E 251 or E 252) have a low toxicity but long-term exposure is of concern, as the lower gut reduces them to nitrite, a precursor of nitrosamines (classified as carcinogenic). Nitrite itself is classified as probably carcinogenic to humans. The European Food Safety Authority (EFSA) lists the MPL (maximum permitted levels) after the manufacturing process for nitrite (labeled E 249 or E 250) as between 50–180 mg/kg, and for nitrate between 150–300 mg/kg, depending on the product. The European Commission (Regulation (EC) No 1333/2008) limits nitrate and nitrite salts in processed meat to less than 150 mg/kg. Ion chromatography with UV detection offers a robust and universal method for quality control of nitrite and nitrate in different meat matrices. Additional sample preparation techniques like Inline Ultrafiltration help to save time and costs as well as overcome analysis issues with difficult sample matrices.

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.

This Application Note presents the Mott-Schottky measurement, an extension of electrochemical impedance spectroscopy (EIS), on a popular semiconducting material.

Anodizing metal surfaces improves resistance against corrosion and wear. Etching baths can be monitored precisely online with the 2060 TI Process Analyzer or 2026 HD Titrolyzer.

This Application Note presents a potentiometric titration method for a potassium bicarbonate and potassium carbonate assay meeting all USP General Chapter <1225> requirements.