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Determination of silicate in tap water using anion chromatography with direct conductivity detection.

Determination of chromate using anion chromatography with post-column reaction and UV/VIS detection.

Determination of fosetyl-aluminum (aluminum tris(o-ethylphosphate)) using anion chromatography with direct conductivity detection.

Determination of carbonate in washing powder using anion chromatography with direct conductivity detection.

Determination of borate and silicate in washing powder using anion chromatography with direct conductivity detection.

Determination of acetate, chloride, citrate, and sulfate in a concentrate of an infusion solution using anion chromatography with direct conductivity detection. Non-suppressed IC is used to avoid interferences by the amino acids.

Determination of borate and silicate in ultrapure water using anion chromatography with direct conductivity detection.

Determination of chloride and sulfate in a reactive dye using anion chromatography with direct conductivity detection. Suppressed IC does not work as the dye is hydrolyzed in alkaline solution and releases sulfate.

Determination of silicate and borate and their limits of determination (LOD) and quantification (LOQ) according to the EPA procedure for method detection limit (MDL) using anion chromatography with direct conductivity detection and Metrohm Inline Calibration.

Determination of acetate, chloride, and malate in an infusion solution using anion chromatography with direct conductivity detection.

Determination of acetate, phosphate, chloride, and citrate in an infusion solution using anion chromatography with direct conductivity detection.

Determination of nitrate in a nickel plating bath using anion chromatography with UV/VIS detection (205 nm).

Determination of sodium dodecylsulfate (SDS, sodium laurylsulfate) using anion chromatography with direct conductivity detection.

Determination of borate in a borate effluent using anion chromatography with direct conductivity detection.

Determination of phenol, m-cresol, 2,6-dimethylphenol and 2,3,6-trimethylphenol in tap water with amperometric detection using a glassy carbon electrode.

Determination of chloride and sulfate in effluent after Metrohm Inline Dialysis using anion chromatography with direct conductivity detection.

Determination of sulfide in an effluent sample using anion chromatography with amperometric detection.

Alendronate, also referred to as alendronic acid, is a biphosphonate used to treat osteoporosis. It is the main ingredient in the tablets and is determined in accordance with the Chinese Pharmacopoeia (2015). Separation takes place in the Metrosep A Supp 4 - 250/4.0 column; direct conductivity detection is used for quantification.

Pure sodium chloride contains much less iodide than e.g., table salt which usually is fortified with it. Trace determination of iodide is easily performed applying ion chromatography with amperometric detection. This detection mode is particularly selective and sensitive. The actual separation is achieved using a Metrosep A Supp 5 - 250/4.0 column. The detection happens at a silver working electrode. LOQ is at approximately 1.0 μg/L (in solution) and 50 μg/kg in the sample. The use of a shorter column might further improve the LOQ.

Two of the leading pain remedies, aspirin and acetaminophen, are compared with generic samples for content uniformity testing using near-infrared spectroscopy (NIRS). The method of standard addition is used for quantification. To reduce most of the effects that stem from particle size and packing differences, second derivative spectra are used.

This Application Note shows the potential of NIRS as a rapid (< 30 s) and nondestructive screening tool for solid dosage forms (e.g. tablets). NIRS requires neither sample preparation nor solvent use. Interferences that derive from scattering are minimized by converting to second derivative spectra.

This Application Note describes the determination of copolymer levels in polyethylene (PE) and polyvinylacetate (PVA) pellets using NIRS. The determination of the composition of the polymer blends takes less than 30 seconds and requires no sample preparation. The second derivative spectra are analyzed by means of the linear least-squares regression method.

This Application Note shows that NIR spectroscopy is an excellent tool for determining low concentrations of additives in finished polypropylene pellets. This is demonstrated by monitoring the UV stabilizer Tinuvin 770 and the antioxidant Irganox 225. The application of multiple linear regression (MLR) models minimizes interferences that originate from different coating thicknesses and interferences in the polymer pellets.

This Application Note demonstrates how NIR spectroscopy can be used to determine the content of coatings on nylon fibers, quickly and without requiring either sample preparation or the use of reagents. In order to suppress the effects arising from scattering on the surface coatings, one forms the second derivative spectra; the linear least-squares regression method is used to calculate the calibration function.

This Application Note describes how NIR spectroscopy can be used to determine residual lignin content in wood pulp. Using the major absorbance peaks of both lignin and cellulose in the second derivative spectra, the residual lignin content in wood pulp can be monitored during paper production.

Near-infrared spectroscopy (NIRS) is ideally suited to monitor the hardwood and softwood content in pulp and paper products.The herein described method bases on the fact that the changes in hardwood and softwood content are reflected in the intensity of the absorption bands of cellulose. A linear least-squares regression on second derivative spectra provide results that correspond very well with those of conventional laboratory determinations. With NIRS, an analytic method is available that provides results in real time.

This Application Note describes an NIR method for monitoring the esterification process in butyl acetate production. The developed NIR method shows excellent analytical performance equivalent to that obtainable with more time-consuming GC methods.

This Application Note demonstrates that a calibration model for caffeine and microcrystalline cellulose developed on the NIRS XDS Rapid Content Analyzer (RCA) is transferable to other NIRS XDS RCA. Due to the improved signal-to-noise ratio, reduced bandwidth and improved wavelength precision of the NIRS XDS, the transferability of the calibration model can be easily and efficiently performed.

This Application Note describes how the accuracy of your NIR measurements can be increased with instrument calibration.

This Application Note describes how the accuracy of your NIR measurements can be increased with reference standards.

Well-mixed active substances for medications are indispensable in the pharmaceutical industry. This applies not only to the pharmaceutical active ingredient but also for lubricants, binding agents, explosives, oxidants and dyes. Analysis of these active ingredients is expensive; they are also only rarely analyzed as a rule. The progress of the mixing procedures can be followed conveniently with NIR spectroscopy, on the one hand using visual comparisons and on the other by means of spectral algorithms. The progress of mixing processes can be predicted in real time with the help of the spectrum when the latter is used.

This Application Note describes the utilization possibilities of a new sensor design that permits, in combination with an NIRS XDS Process Analyzer, the determination of solvent residues in a High-Shear Granulator during the drying phase. This system configuration reduces the scattering of the density distribution of the powder samples so that it is possible, directly in the process, to model the water and solvent content precisely.

This Application Note shows that NIR "predictive models" are optimally suitable for the non-destructive measurement of the release profiles of active ingredients from tablets. This is in accordance with the Process Analytical Technology (PAT) initiative of the FDA. The results demonstrate how NIRS considerably reduces the work involved for release studies in the laboratory.

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.

The determination of the water content of soft contact lenses using NIR spectroscopy is described in this Application. A liquid sample kit with gold diffuse reflector was used for measuring the lenses in transflexion mode. A PLS model was developed for predicting the water content.

The purity of a recovered solvent (dichlormethane/methylene chloride) and two of its most important contaminants (methanol and water) are monitored with NIR spectroscopy.

In recent years, there has been a significant push to reduce the environmental impacts of fuels through improvements to fuel quality. The determination of key quality parameters of gasoline, namely research octane number (RON, ASTM D2699-19), motor octane number (MON, ASTM D2700-19), anti knock index (AKI), aromatic content (ASTM D5769-15), and density, conventionally requires several different analytical methods, which are laborious and need trained personnel. 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 multiparameter analysis of gasoline.

Determination of the diethylene glycol content, isophthalic acid content, intrinsic viscosity (ASTM D4603), and the acid number (AN) of polyethylene terephthalate (PET) is a lengthy and challenging process due to the sample’s limited solubility and the need to use different analytical methods. 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 these parameters in PET. Vis-NIR spectroscopy allows for the analysis of PET in less than one minute without sample preparation or using any chemical reagents.

Pyrolysis gasoline (Pygas) is a by-product of ethylene production, which contains unwanted conjugated diolefins making it unsuitable as a motor fuel. To overcome this limitation, the olefin content needs to be reduced below 2 mg/g pygas in a selective hydrogenation unit (SHU). The diene value, or maleic anhydride value (MAV), is usually determined by the lengthy Diels-Alder wet chemical method (UOP326-17), requiring highly trained analysts. In contrast to the primary method, near-infrared spectroscopy (NIRS) is a cost-efficient and fast analytic solution for the determination of diene value in pyrolysis gasoline.

This Application Note describes the determination of various indices (mainly with ASTM and ISO conformance) for the characterization of kerosene as aviation turbine fuel using near-infrared spectroscopy. The following parameters were determined with the aid of an NIRS XDS Process Analyzer: degree of density in accordance with the American Petroleum Institute (API), aromatics content, Cetane Index, distillation characteristics pursuant to ASTM D86, flash point, freezing point, viscosity and hydrogen content. All of these parameters are determined quickly and easily with just a single measurement.

Ink is a complex mixture that, along with numerous additives, is comprised mainly of solvent, dye, water and surfactant. Vis-NIR spectroscopy is outstandingly suitable for providing rapid and reliable determinations of constituents in the context of quality controls. This Application Note describes the determination of diethylene glycol (DEG), water, dye and surfactant.

This Application Note shows how, with the help of Vis-NIR spectroscopy and a special plant library, 46 different medicinal and aromatic plants, e.g., Organicum majoricum and Tilia cordata, can be conveniently identified on the basis of their spectrum. In comparison with alternative methods for the determination of plants, which are elaborate and require experienced scientists for their performance, the Vis-NIR method permits rapid and uncomplicated identification.

This Application Note shows the transfer of near-infrared spectroscopy analysis methods from the FOSS NIRSystems System II (5000/6500) Analyzer to the Metrohm NIRS XDS und DS2500 Analyzers. In addition, the advantages of the new NIRS XDS and DS2500 analyzers with extended spectral range and improved resolution are displayed, in particular with respect to the FOSS NIRSystems System II analyzer.

This Application Note shows the determination of two important additives – butylglycol and propylheptyl alcohol – in water-soluble lacquers using Vis-NIR spectroscopy. Other lacquer constituents can also be determined in addition to the two additives.

This Application Note shows how the amine number and the solids content in electrophoretic lacquer coatings can be determined quickly and simply with Vis-NIR spectroscopy. Additional parameters can be determined reliably and conveniently with a single measurement.

This Application Note shows how purity, degree of substitution and water content of carboxymethyl celluloses (CMC) can be determined conveniently and rapidly in a single measurement with Vis-NIR spectroscopy.

This Application Note shows the determination of the ratio of cotton linter to pulp in cellulose samples with Vis-NIR spectroscopy. This linter-pulp ratio is an important characteristic in the paper industry which, unlike with elaborate wet-chemistry methods, can be determined quickly and conveniently with Vis-NIR spectroscopy.

This Application Note describes the simultaneous determination of the four most important analysis parameters of paint dryers – cobalt and solids contents, specific weight and viscosity – using a VIS-NIR analyzer. The visible range correlates with the metal content, while the NIR region provides the specific weight, viscosity and solids content.

This Application Note shows that near-infrared spectroscopy with its exceptionally short analysis times significantly accelerates quality monitoring of polymer granulates and raw materials. Polyethylene (PE) und polypropylene (PP) can be identified in parallel. PE density is also determined in the same measurement.

Polyols are widely used as polyurethane feedstocks, where tight quality control of parameters such as hydroxyl value, acid number, moisture, and viscosity is essential. Conventional titration methods are standardized but slow and costly due to hazardous chemicals and waste handling. Near-infrared spectroscopy (NIRS), recognized by ASTM for hydroxyl value determination, enables rapid, reagent-free, multiparameter analysis of polyols with significantly lower operating costs.

This Application Note shows the fast and parallel determination of water content and pH value in crude tall oil samples using near-infrared spectroscopy (NIRS). Crude tall oil is an important byproduct of pulp production in the power process. NIRS is an efficient alternative to conventional laboratory methods: It permits rapid raw material inspection, process monitoring and final product checking.

Sulfathiazoles are sulfonamides with antibiotic effect that occur in various polymorphous forms and that are often used in veterinary medicine. This Application Note shows the differentiation between commercial and sulfathiazole form I using near-infrared spectroscopy (NIRS) with the help of the overtone frequencies of N-H stretching vibration. Form I is the least stable polymorphous form. Crystallization and polymorphism must be monitored as part of quality controls. In this, NIRS is considerably more rapid and more reliable than conventional laboratory methods.

In this Application Note, Vis-NIR spectroscopy (Vis-NIRS) is used to determine six wood pulp properties in a single measurement: kappa number, applied density, freeness, breaking strength, buckling strength and tensile strength.

This Application Note describes the quantification of protein content in dietary supplements using Vis-NIR spectroscopy to reduce the workload of time-consuming and waste-generating primary methods, such as Kjeldahl digestion.

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.

Heparin acts as an efficient anticoagulant and, in addition to direct injection, is also used as a lock-flush solution for rinsing catheters. Vis-NIR spectroscopy can be used to determine the strength of contaminated and purified heparin. This Application Note demonstrates that heparin strength can be determined reliably with Vis-NIR spectroscopy.

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.

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.

Vis-NIR spectroscopy is used to determine the droplet morphology in hair conditioner. This Application Note shows that near-infrared (NIR) spectroscopy can be used to distinguish between unprocessed and processed hair conditioner and to qualify quality parameters such as the droplet size.

Visible Near-infrared (Vis-NIR) spectroscopy is a valuable chemical analysis tool that can be used to determine quality parameters of hair creams. A qualitative method was developed in order to allow a fast out-of-spec analyses of an active antibacterial ingredient.

Near-infrared spectroscopy (NIRS) was used as an analysis method for quality control of hair spray samples. A model for an active ingredient within hair sprays was developed, enabling fast and reliable out-of-specification analyses.

Visible near-infrared (Vis-NIR) spectroscopy can be used as a fast and accurate analytical method for the quantification of different analytes and active ingredients in detergents, such as tetraacetylethylendiamin (TAED), sodium percarbonate (PCS), and enzymes. This Application Note shows how NIRS can be used for multi-constituent analyses in detergents in a single measurement.

Near-infrared spectroscopy (NIRS) was used in a preliminary study as a fast and accurate method for the quantification of different preservatives and active ingredients in liquid shampoo. This Application Note shows how this analytical method allows the simultaneous determination of several constituents in shampoo in a single measurement.

Near-infrared spectroscopy (NIRS) was used as an analysis method for quality control of soap noodles. Quantitative models for the determination of Total Fatty Matter, Iodine Number, and C8–C14 were developed, enabling fast and reliable quality control.

Near-infrared spectroscopy (NIRS) was used as an analysis method for quality control of aqueous xanthan gum solutions. Quantitative models for the determination of optical density, glucose, and xanthan gum were developed, enabling fast and reliable quality control.

This Application Note shows that visible near-infrared spectroscopy (Vis-NIRS) can determine water content in ethanol-hydrocarbon blends. Vis-NIRS is a fast alternative to conventional lab methods: it accelerates raw material inspection, process monitoring, and final product control.

Determination of sodium laureth sulfate (SLES), cocamidopropyl betaine (CABP), cocamidopropylamine oxide (CAW), cocamide diethanolamine (DEA), and carbopol in shampoo is a cost- and time-intensive process due to the use of large volumes of chemicals per analysis. 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 these parameters in shampoo. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the complete analysis in less than a minute.

Near-infrared spectroscopy (NIRS) was used for quality control of skin creams. A model for the quantification of the water content was developed based on Karl Fischer titration (KF), enabling fast and reliable atline analysis and final product quality control.

This Application Note shows that visible near-infrared spectroscopy (Vis-NIRS) can be used for the quantification of five effective insecticide and herbicide components (Abamectin emulsifiable concentrate (EC), Emamectin EC, Cyhalothrin EC, Cypermethrin and Glyphosate) in pesticides. Vis-NIRS is an excellent alternative to conventional lab methods, saving both cost and time.

This Application Note shows that visible near-infrared spectroscopy (Vis-NIRS) can be used for the quantification of Baicalin content in herbal supplements. Vis-NIRS is a good alternative to the conventional lab method (HPLC) and can save both cost and time.

This Application Note shows that the visible range of the Metrohm Vis-NIR analyzer can be used to quantify the color intensity of dyes, providing comparable results to the reference analysis UV-Vis. The NIR region can be used in addition to distinguish between different dye types or different suppliers and can identify impurities in the undiluted dyes during raw material control. The combination of the visible and near-infrared wavelength ranges offer the benefit that only one analyzer is required to receive results on multiple parameters in a 30-seconds-scan results on both cost and time saving.

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.

This Application Note describes a fast, nondestructive, and reliable method for the determination of the chemical composition of alcohol mixtures exemplified by ethanol/isopropanol mixtures. With visible near infrared spectroscopy (VIS-NIRS), results are available in real-time, thus making NIRS highly suited for fast quality control.

This Application Note shows that visible near-infrared spectroscopy (Vis-NIRS) can determine the sun protection factor (SPF) of sunscreen products. Thanks to measurement durations of less than 30 seconds, NIR spectroscopy is ideally suited for rapid and reliable quality control.

Uniformity of dosage units must be tested for QC purposes in the pharma industry. NIRS gives results in seconds along with the quantification of APIs and excipients.

Specialty chemicals have to fulfill multiple quality requirements. One of these quality parameters, which can be found in almost all certificates of analysis and specifications, is the moisture content. The standard method for the determination of moisture content is Karl Fischer titration.This method requires reproducible sample preparation, chemicals, and waste disposal. Alternatively, near-infrared spectroscopy (NIR) can be used for the determination of moisture content. With this technique, samples can be analyzed without any preparation and without using any chemicals.

This Application Note presents Vis-NIR spectroscopy as a viable alternative to determine API content in cefixime tablets without sample preparation.

This Application Note demonstrates the feasibility of Vis-NIRS for the simultaneous determination of multiple chemical and physical parameters in epoxy resins. Vis-NIRS is a fast alternative to conventional lab methods: it accelerates raw material inspection, process monitoring, and final product control.

Control of NCO content in isocyanates is essential for polyurethane production. However, wet chemistry methods are slow, hazardous, and preparation intensive. Near-infrared spectroscopy (NIRS) offers a rapid, reagent-free alternative, determining NCO content in seconds without sample preparation. This makes NIRS a practical and environmentally compliant solution for routine quality control of isocyanate raw materials.

Rapid quality control for toothpaste is achieved by Metrohm`s Vis-NIR analyzers. Vis-NIR technology offers significant advantages compared to standard reference analysis. It is a cost effective and safe method because no hazardous chemicals are used.

This Application Note describes a fast method for the simultaneous quantification of nicotine and glycerin in liquid mixtures used for electronic cigarettes. With visible near infrared spectroscopy (VIS-NIRS), results are available without sample preparation, thus making VIS-NIRS highly suited for fast quality control.

Acid Number (AN) analysis of lubricants (ASTM D664) can be a lengthy and costly process due to usage of large amounts of chemicals and required cleaning steps of the analytical equipment between each measurement. This application note demonstrates that the XDS RapidLiquid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a cost-efficient, fast alternative for the determination of the acid number of lubricants. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows for the analysis of AN in less than a minute.

Packaging has become an indispensable part in the food manufacturing process. To improve the appearance and properties of the packaging, a wide variety of coatings and inks are used. Different additives enhance rheological properties, control the wetting dispersion, or in the case of wax increase abrasion resistance. The regulations of these coatings in food packaging applications are very strict in some countries, creating the need for close monitoring of the production process.A fast, reliable, and simple to use solution for quantifying rheological additives and wax in such coatings is Visible-Near Infrared Spectroscopy (Vis-NIRS). Both parameters are determined simultaneously by Vis-NIRS in less than a minute.

Water activity is an important parameter to measure for non-sterile pharmaceutical quality and stability. The OMNIS NIR Analyzer provides this data within seconds.

This Application Note shows how NIRS is used for the multiparameter analysis of dry matter, pH value, viscosity, and surfactant content in liquid laundry detergent.

Naphtha is the first petroleum product during the distillation process of crude oil or coal tar. It is primarily used as a base material for the production of gasoline or as a solvent. Accidental spills occur regularly at many locations throughout the world, leading to soil contamination.Investigation of contaminated sites is usually performed using gas chromatography, for which the soil sample has to be frozen, grinded, and subsequently extracted prior to the analysis. Using Visible-Near Infrared Spectroscopy such sample preparation steps are not necessary at all, making this method a viable, fast, and simple to use alternative.

Polyvinyl alcohol (PVA) is a linear polymer, used in a variety of medical products (e.g. eye drops). Here, the degree of alcoholysis is an important index for the water solubility, viscosity, and adhesion of the product. The degree of alcoholysis is defined as the percentage of hydroxyl functional groups compared to the total functional groups accessible in the molecule. Conventional alcoholysis determination can take up to six hours per sample. Compared to the primary method, analysis with near-infrared spectroscopy (NIRS) only takes one minute. The following application note describes the determination of the degree of alcoholysis by NIRS.

Caprolactam is an important polymer used for the production of Nylon 6, which is the base material for industrial fibers. Due to its commercial significance, many different synthesis methods have been developed over the years. Caprolactam is hygroscopic and water soluble, therefore it is important to have a reliable analysis technique for water determination. Analyzing the water content by conventional methods requires each sample to be weighed, dissolved, heated, and titrated. Compared to the primary method, near-infrared spectroscopy (NIRS) offers unique advantages: it generates reliable results within seconds, but it does not need any sample preparation nor does it create chemical waste.

The quantification of residual moisture in lyophilized pharmaceutical peptides is an important measure for quality control in the pharmaceutical industry. For development purposes, such measurements are necessary and routinely performed during stability studies and to optimize the freeze-drying process (lyophilization). Currently, Karl Fischer titration is widely used for moisture determination in routine analysis. However, this method is time consuming and destroys the sample during analysis. This Application Note shows that near-infrared spectroscopy (NIRS) is a fast, reagentless, non-destructive method to determine moisture content in lyophilized pharmaceutical products.

Moisture content is one of the most commonly measured properties of fertilizers. Globally, regulations for different fertilizers vary, but local legal limits ensure that the maximum amount of water must not be exceeded. Next to gravimetric methods, Karl Fischer titration is often used for accurate moisture determination.Compared to these methods, near-infrared spectroscopy (NIRS) offers unique advantages: it generates reliable results within seconds, and at the same time does not create chemical waste. This Application Note explains how NIRS can offer fast, reagent-free analysis of moisture content in various fertilizer products.

The cetane index (ASTM D613), flash point (ASTM D56), cold filter plug point (CFPP) (ASTM D6371), D95 (ISO 3405), and viscosity at 40°C (ISO 3104) are key parameters to determine for diesel quality. The primary test methods are labor intensive and challenging due to the need to use different analytical methods. This application note demonstrates that the NIRS XDS RapidLiquid Analyzer provides a cost-efficient and fast solution (under 1 minute) for the simultaneous determination of these key parameters in diesel.

Determination of the density of polyethylene (PE) (ASTM D792) is normally a challenging procedure due to reproducibility difficulties. Measurement via FT-IR can be problematic when larger sample sizes must be analyzed due to sample inhomogeneity. This application note demonstrates that the DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) provides a reliable and fast solution for determination of the density of PE. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the analysis of larger, inhomogeneous sample sizes of PE in less than a minute.

Polypropylene (PP) is a general purpose resin widely used in industries such as electronic manufacturing and construction, as well as in packaging materials. PP resins must be melted first in order to be formed into the intended shape, and therefore flow properties are important characteristics which affect the production process. The standard procedure to analyze melt flow rate (MFR) requires a significant amount of work with packing the sample, preheating, and cleaning. With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the analysis of MFR in less than a minute.

Identification of individual polymers with FT-IR spectroscopy can be a challenge due to sample inhomogeneity especially when larger sample sizes need to be analyzed. This application note demonstrates that the DS2500 Solid Analyzer operating in the visible and near infrared spectral region (Vis-NIR) provides a reliable and fast solution for the identification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP). With no sample preparation or chemicals needed, Vis-NIR spectroscopy allows the identification of larger inhomogeneous sample amounts in less than a minute.

Determination of the vinyl content of silicone rubber is a lengthy and challenging process. First, the vinyl groups must be converted to ethylene by reacting with an acid, followed by the determination of the produced ethylene with gas chromatography (GC).This application note demonstrates that Vis-NIR (visible near-infrared) spectroscopy provides a cost-efficient and fast solution for the determination of vinyl content in silicone rubbers. With the DS2500 Solid Analyzer it is possible to obtain results in less than a minute without sample preparation or any chemical reagents.

The quality control of diesel exhaust fluids (DEF) is key to ensure the optimal catalytic performance and prevent damage to the exhaust system in diesel vehicles. The standard method to determine urea content is measuring the refractive index (ISO 22241-2:2019). The issue is that although this method is fast, it is not as accurate as other methods (e.g., HPLC). This application note demonstrates that the DS2500 Liquid Analyzer provides a fast solution with high accuracy for the determination of urea in DEF. With no sample preparation or chemicals needed, visible near infrared (Vis-NIR) spectroscopy allows for the analysis of diesel exhaust fluids in less than a minute.

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.

Cannabidiol (CBD) is a popular natural remedy from the cannabis plant used in many pharmaceutical, food, and cosmetic products. Unlike tetrahydrocannabinol (THC), CBD is not psychoactive, making it an appealing option for those who are looking for relief from pain and other symptoms without mind-altering effects. CBD oil is made by extracting the cannabinoid from the plant, then diluting it with a carrier oil (e.g., coconut or hemp seed oil). The standard HPLC method requires 45 minutes to perform by highly trained analysts. In contrast to the primary method, Vis-NIR spectroscopy is a cost-efficient and fast analytical solution for the determination of cannabinoid content in edible oils.

In the semiconductor industry, thermoset resins combined with fabric or paper are used as an intermediate layer between substrates of printed circuit boards (PCB). These polymer-based sheets (laminates) are chosen depending on thickness and their thermomechanical and electrical characteristics. Near infrared spectroscopy (NIRS) is a fast, non-destructive and easy-to-use analytical method which allows the measurement of multiple key quality parameters in less than a minute. The following Application Note describes the determination of the transition time of PCB laminates by NIRS, a parameter correlating with the thickness, glass transition temperature, and tensile strength of the material.

Fast and reliable detection of phosphoric, sulfuric, nitric, and hydrofluoric acids with near-infrared spectroscopy in under one minute.

This application note discusses an alternative near-infrared (NIR) spectroscopy method that can reliably determine all parameters within a minute, even in complex acid mixtures.

PVC (polyvinyl chloride) foils with a PVDC (polyvinylidene chloride) coating are often used for high performance packaging films like pharmaceutical blister packs or in food packaging. In multi-layer blister films, the PVC serves as the thermoformable backbone structure, whereas the PVDC coating acts as a barrier against moisture and oxygen. The Water Vapor Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR) are influenced by the composition and the thickness of the coating. A fast way to monitor PVDC coating thickness is with near-infrared spectroscopy. Results are provided in a few seconds, indicating when adjustments in the polymer production process are necessary.

The production of biofuels from renewable feedstock has grown immensely in the past several years. Bioethanol is one of the most interesting alternatives for fossil fuels, since it can be produced from raw materials rich in sugars and starch. Ethanol fermentation is one of the oldest and most important fermentation processes used in the biotechnology industry. Although the process is well-known, there is a great potential for its improvement and a proportional reduction in production costs. Due to the seasonal variation of feedstock quality, ethanol producers to need to monitor the fermentation process to ensure the same quality product is achieved. Near-infrared spectroscopy (NIRS) offers rapid and reliable prediction of ethanol content, sugars, Brix, lactic acid, pH, and total solids at any stage of the fermentation process.

This application note presents near-infrared spectroscopy (NIRS) as an alternative for bromine number determination in pyrolysis gasoline.

This application note presents near-infrared spectroscopy (NIRS) for the rapid and reliable simultaneous quantification of ethanol, glycerol, hydrogen peroxide, and water content in hand sanitizer formulations.

This Application Note highlights near-infrared spectroscopy as a faster, cost-effective alternative to KF titration for predicting water content in diesel fuel.

Alkaline additives in engine lubricants are used to prevent the build-up of acids and as a result, they inhibit corrosion. The total base number (TBN) indicates the amount of basic additives present in samples and thus can be used as a measure for the degradation of the lubricant. The standard test method for TBN in lubricants is potentiometric titration according to ASTM D2896. This method requires the use of toxic reagents involves a labor-intensive cleaning procedure. In contrast to the primary method, near-infrared spectroscopy (NIRS) is a fast analytical technique which does not produce any chemical waste and completes the TBN analysis in less than one minute.

To monitor the quality of PVC (polyvinyl chloride), it is important to measure the molecular weight during the production process, as this parameter has a significant influence on chemical and mechanical stability as well as fire retardant properties. The standard method to determine PVC molecular weight, defined here as the average weight of the molecules that make up the polymer, is by size exclusion chromatography (SEC). This analytical method is time-intensive and requires trained personnel to perform. Determining the molecular weight of PVC is easier with near-infrared spectroscopy (NIRS). NIRS provides results in just a few seconds and can quickly indicate when adjustments to the production process are necessary.are necessary.

Cell fermentation processes are a reliable production method for small molecules and protein-based active pharmaceutical ingredients (APIs). The fermentation process requires monitoring of many different parameters to ensure optimal production. These quality parameters include pH, bacterial content, potency, glucose, and concentration of reducing sugars. Traditional laboratory analysis takes a significant amount of time and requires different analytical techniques to monitor these different quality parameters. Near-infrared spectroscopy (NIRS) offers a faster and more cost-efficient alternative to traditional methods for the determination of critical parameters in fermentation broths at any stage of the fermentation process.

The standard test method for ash content analysis is thermogravimetric analysis (TGA). Although TGA is easy to perform, it is time-intensive and requires the use of nitrogen gas. In contrast to the primary method, near-infrared spectroscopy (NIRS) is a fast analytical technique which can measure multiple parameters including ash content in polymers within one minute.

Typically, cannabis potency testing is performed by HPLC, but the drawback is that it requires chemicals and it is time-consuming. Near-infrared spectroscopy (NIRS) is a preferred method for quantification of THC, CBD and CBG in dried cannabis because it provides results in less than a minute and does not require any chemicals.

This Application Note shows the feasibility of NIR spectroscopy for the analysis of density in polyethylene granulates. Compared to the standard method, NIRS analysis shows a lower prediction error when air bubbles are present in PE pellets.

Near-infrared spectroscopy (NIRS) is a fast, chemical-free analysis method for various quality parameters of chocolate bars without sample preparation. The NIRS solution is easy to use and can be used atline or in a quality control lab.

Near-infrared spectroscopy (NIRS) is a fast, chemical-free analytical method for the simultaneous analysis of density, water activity, and moisture of green coffee beans.

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) allows the simultaneous determination of sweeteners such as Stevia and sucralose in blends in less than one minute without any chemicals or sample preparation.

The synthetic rubber known as Bromobutyl (BIIR) has many of the attributes of butyl rubber, but has better adhesion to other rubbers and metals, resulting in substantially faster cure rates. The simultaneous quantification of the bromine content, Mooney viscosity, volatile content, calcium stearate content, and functional bromide in BIIR can be easily performed with near-infrared spectroscopy (NIRS) without the use of chemicals.

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.

Key quality parameters in the food industry include sucrose, glucose, and fructose, and Brix (dissolved sugar content). Near-infrared spectroscopy (NIRS) allows fast simultaneous determination of multiple sugars without chemicals or any sample preparation.

Brix, Pol, juice purity, reducing sugars, and total recoverable sugars are some of the many quality control (QC) parameters that must be analyzed in sugarcane juice. An alternative to other analytical methods is near-infrared spectroscopy (NIRS). NIRS allows the fast, simultaneous determination of several QC constituents without chemicals or sample preparation.

Near-infrared spectroscopy can quickly determine multiple edible oil quality parameters simultaneously without sample preparation as shown in this Application Note.

Near-infrared (NIR) spectroscopy is able to determine the intrinsic viscosity of rPET in less than one minute without any sample preparation. This Application Note demonstrates that the Metrohm DS2500 Solid Analyzer operating in the visible and near-infrared spectral region (Vis-NIR) offers users an easier way to perform this analysis without the use of toxic chemicals.

The standard method to determine RON in isomerate is with expensive and maintenance-intensive engines. In contrast to this, the research octane number can also be analyzed by near-infrared spectroscopy (NIRS). NIRS provides accurate results within one minute without the need for any sample preparation or chemicals.

The determination of key quality parameters of reformate—namely research octane number (RON, ASTM D2699-19), aromatic content (ASTM D5769-15), benzene content, olefin content, and density—requires time-consuming and laborious conventional methods. In contrast, the Metrohm DS2500 Liquid Analyzer can measure all of these parameters, providing results within one minute without any sample preparation.

Near-infrared spectroscopy (NIRS) quickly assesses key quality parameters in palm oil such as iodine value and fatty acid profile without sample preparation.

Monitoring the iodine value in edible oil blends is crucial to produce vegetable oils with the desired properties. This Application Note displays the benefit of using the Metrohm NIRS DS2500 Liquid Analyzer for quality control in food laboratories.

Conventional methods used to analyze moisture, ash, fixed carbon, and volatile content in coal samples, are time consuming and costly. Near-infrared (NIR) spectroscopy is excellently suited to determine all parameters simultaneously in less than one minute without any sample preparation.

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

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

Near-infrared spectroscopy (NIRS) can determine water content in PGME (propylene glycol monomethyl ether) within seconds as shown in this Application Note.

This Application Note shows how easy it is to determine water content in the pharmaceutical excipient lactose with reagent-free near-infrared spectroscopy.

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

Polypropylene and polyethylene can pose recycling challenges. With near-infrared spectroscopy (NIRS), users receive polyolefin composition results in seconds.

Near-infrared spectroscopy (NIRS) offers a fast, solvent-free alternative to traditional methods for assessing olive oil quality and detecting potential food fraud.

Determination of the biodiesel content in diesel with NIR spectroscopy is fast and requires no sample preparation nor chemicals, reducing workload and costs.

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.

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.

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.

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

This Application Note shows how NIR spectroscopy is used to determine the water content (moisture content), protein content, and fat content in whole and ground almonds.

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.

This study shows how NIR spectroscopy simultaneously measures capsaicin content, Scoville Heat Units, water activity, ASTA color, and ash content in paprika powder samples.

NIR spectroscopy can measure several honey quality parameters simultaneously in just a few seconds without any sample preparation as shown in this Application Note.

This Application Note shows how near-infrared spectroscopy is used for fast, chemical-free multiparameter quality control of fabric softeners and laundry perfumes.

NIR spectroscopy is an alternative method for olive pomace fat analysis. Unlike other conventional methods, NIRS requires no sample preparation nor chemical solvents.

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

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

Near-infrared spectroscopy (NIRS) can simultaneously determine different quality parameters in deodorants like viscosity, pH, density, and aluminum content.

Ethanol content can be quickly and easily determined in different wines during fermentation and afterwards for quality control using near-infrared spectroscopy.

Corn starch serves as a gelling and thickening agent in the confectionary industry. It is also an ideal reusable molding and drying medium for starch-molded candies, where its moisture content is critical to monitor. Near-infrared spectroscopy (NIRS) provides a rapid, reagent-free method to determine moisture and protein content in corn starch. The technique is straightforward to operate and suitable for atline monitoring or routine quality control laboratories.

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.

Determination of lauric acid, myristic acid, palmitic acid, and stearic acid using ion-pair chromatography with direct conductivity detection.

Determination of glycolic acid and monochloroacetic acid in cocoamidopropyl betaine using ion-exclusion chromatography with direct conductometric detection.

Determination of citrate and acetate in isotonic solutions using ion-exclusion chromatography with direct conductivity detection.

Determination of citric acid and ascorbic acid in vitamin tablets using ion-exclusion chromatography with direct conductivity detection.

Determination of citric acid and tartaric acid in fruit salt using ion-exclusion chromatography with direct conductivity detection.

Determination of organic acids and phosphate using ion-exclusion chromatography with direct conductivity detection.

Determination of gluconic acid and glycolic acid using ion-exclusion chromatography with direct conductivity detection.

Determination of citrate and saccharin in a nickel plating bath using ion-exclusion chromatography with direct conductivity detection.

Determination of gluconate and salicylate in a zinc plating bath using ion-exclusion chromatography with direct conductivity detection.

Determination of lactate, formate, and acetate in a cataphoretic paint bath using ion-exclusion chromatography with direct conductivity detection.

Determination of citrate, fluoride, lactate, and acetate in a plating bath using ion-exclusion chromatography with direct conductivity detection.

Determination of formate, acetate, propionate, butyrate, valerate, and capronate in an aqueous absorption solution using ion-exclusion chromatography with conductivity detection after chemical suppression.

Determination of lactate, formate, acetate, propionate, butyrate, isobutyrate, valerate,and isovalerate in a standard solution using ion-exclusion chromatography with conductivity detection after chemical suppression.

Determination of glycolic acid, formic acid, acetic acid and carbonic acid in a scrubber solution using ion-exclusion chromatography with conductivity detection after chemical suppression.

Determination of boric acid and acetic acid in process water using ion-exclusion chromatography with conductivity detection after chemical suppression.

Determination of glycolic acid, formic acid, glutaric acid, acetic acid, propionic acid, and butyric acid in a standard solution using ion-exclusion chromatography with suppressed and non-suppressed conductivity detection.

Determination of citric acid and lactic acid in an electroplating bath using ion-exclusion chromatography with conductivity detection.

Determination of glycolic acid, formic acid, glutaric acid, acetic acid, propionic acid, and butyric acid in paper industry process water using ion-exclusion chromatography with suppressed conductivity detection.

Determination of acetic, propionic, isobutyric, butyric, isovaleric, valeric, and caproic acid in potato juice using ion-exclusion chromatography with suppressed conductivity detection.

Determination of carbonate in an aqueous ammonia solution using ion-exclusion chromatography with suppressed conductivity detection.

Determination of citrate, ascorbate, and acetate in a food additive using ion-exclusion chromatography with suppressed conductivity detection.

Determination of sorbate and benzoate in a functional drink using ion-exclusion chromatography with suppressed conductivity detection.

Determination of L-lactide, citrate, and lactate in an acetone solution using ion-exclusion chromatography with direct conductivity detection.

Determination of citrate, succinate, lactate, β-hydroxybutyrate, and acetate in dry albumin powder using ion-exclusion chromatography with suppressed conductivity detection and dialysis for inline sample preparation.

Determination of citrate, ascorbate, and acetate in photographic developer solution using ion-exclusion chromatography with suppressed conductivity detection.

Determination of fumarate, lactate, formate, and propionate in animal food using ion-exclusion chromatography with suppressed conductivity detection.

Determination of carbonate in tap water using ion-exclusion chromatography with suppressed conductivity detection.

Determination of carbonate in sparkling water using ion-exclusion chromatography with suppressed conductivity detection.

Determination of malate and ascorbate in orange juice using ion-exclusion chromatography with suppressed conductivity detection and inline dialysis for sample preparation.

Determination of acetate and formate in an amine solution using anion chromatography with conductivity detection after suppression.

Determination of formate, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, and capronate added to tap water using anion chromatography with conductivity detection after suppression. The MCS is placed upstream of the chemical suppressor to remove interfering CO2.

Determination of citric, malic, quinic, succinic, lactic, formic, and acetic acid in roasted coffee using anion chromatography with conductivity detection after suppression.

Determination of sulfite, nitrite, nitrate, sulfate, imidodisulfonate, and peroxodisulfate using ion-pair chromatography with conductivity detection after suppression.

Determination of formate, acetate, propionate, isobutyrate, butyrate, isovaleriate, valeriate, and capronate using ion-exclusion chromatography with suppressed conductivity detection after inline dialysis.

Determination of borate in seawater using ion-exclusion chromatography with suppressed conductivity detection after inline matrix elimination.

Evidence of maleic acid in Asian foodstuffs led to the recall of many starchy foods because long-term consumption of maleic acid can cause kidney problems. Cyclic kojic acid is however approved in Asia, both as a bleaching additive in foodstuffs and as a preservative in cosmetics. This Note describes their simultaneous determination in a single analysis.

Arabinonic acid, glyceric acid, glycolic acid and formic acid can be determined in organic compounds using ion-exclusion chromatography with subsequent conductivity detection in accordance with inverse suppression. The Metrohm Suppressor Module in its lithium form is used for this purpose: This reduces background conductivity and ensures that the acids are present in their completely disassociated Li+ form. The suppressor is regenerated with lithium chloride.

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.

The human daily intake of boron from food and beverages is approximately 2 mg. This is far below any toxic level. Some plants, however, are extremely sensitive to boron concentrations above 1 mg/L, e.g., strawberries, blackberries. As seawater contains 4 to 5.5 mg/L of boron, desalination is required to remove surplus boron besides other ions. This application shows the determination of boron (as borate) by ion-exclusion chromatography with conductivity detection after inverse suppression. The method has been optimized to get a sufficient fluoride/borate separation.

Monoethylene glycol (MEG) is used to remove water from natural gas before further processing. Due to high temperatures applied, glycol degradation to glycolic, formic, and acetic acid may occur. These reactions are unwanted as the emerging acids are corrosive. The determination of the organic acids is achieved by ion-exclusion chromatography with conductivity detection after inverse suppression.

Acidic gas sweetening solvents are used to remove acid gases such as H2S and CO2 from streams. Typically, amines are applied as alkaline components in these solvents. The determination of organic acids (glycolic, acetic, formic, propionic, and butyric acid) is achieved by ion-exclusion chromatography with conductivity detection after inverse suppression.

Sorbic acid and benzoic acid and their salts are used as food preservatives (E200, E201, E201, E203 and E210, E211, E212, E213 respectively). The content of such preservatives in flavored bottled water may easily be analyzed by ion exclusion chromatography. This method determines the concentration of the respective acid and does not allow differentiating between the counter cations. The determination of sorbic acids and benzoic acid is achieved by conductivity detection after inverse suppression.

Separation of polysaccharides with increasing numbers of inulin units using gradient elution and pulsed amperometric detection.

Determination of sucrose, glucose, and sucralose in a low-calorie sweetener using ion-exclusion chromatography with pulsed amperometric detection after post-column addition of sodium hydroxide.

Determination of polysaccharides (n glucose units) in potato starch using pulsed amperometric detection and a high-pressure gradient.

Determination of polysaccharides (n glucose units) in a plant extract using pulsed amperometric detection and a high-pressure gradient.

Determination of phenol, m-cresol, 2,6-dimethylphenol, and 2,3,6-trimethylphenol in tap water using amperometric detection and a glassy carbon electrode.