Aplikácie

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

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

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

Determination of sodium, potassium, and silica values in sodium and potassium silicates.

Determination of free fatty acids (FFA) in oils.

Boric acid is used in many primary circuits of nuclear power plants, in nickel plating baths, and in the production of optical glasses. Furthermore, boron compounds are found in washing powders and fertilizers. This bulletin describes the potentiometric and thermometric determination of boric acid. The determination also covers further boron compounds, when acidic digestion is applied.

The ASTM D8192 standard allows analysts to determine water hardness in different water matrices by complexometry with automated photometric endpoint recognition, increasing the reproducibility and the precision of the results.

This Bulletin describes the potentiometric determination of lead, tin(II), and free fluoroboric acid.

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

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

Chlorine is frequently added to drinking water for disinfection. Depending on the reactivity and the concentration of chlorine, toxic disinfection by-products (DBPs) can thereby be released. Therefore, it is necessary to strictly control the chlorine concentration in the drinking water. This Application Bulletin shows how to determine the chlorine concentration according to three standard methods: DIN EN ISO 7939-1, APHA 4500-Cl Method B, and APHA 4500-Cl Method I.

This Bulletin describes titrimetric methods for the determination of cadmium, free sodium hydroxide, sodium carbonate, and total cyanide. The free cyanide can be calculated from the total cyanide and the Cd content.

The determination of the physical and chemical parameters as electrical conductivity, pH value, alkalinity, the calcium and magnesium hardness as well as the total hardness are necessary for evaluating the water quality. A fast and accurate determination in tap water is realized using an automated OMNIS System working in parallel on different workstations. An 856 Conductivity Module with Dosinos extends the system.

Standardization of copper back-titrant using standard tetrasodium EDTA titrant in the determination of metals.

Several testing methods such as the determination of the acid and the iodine numbers in biodiesel as well as the quantification of sulfate and chloride in bioethanol are described.

Propylene oxide (PO) is a major industrial product used in assorted industrial applications, mainly for the production of polyols (the building blocks for polyurethane plastics). Several production methods exist, with and without co-products. This white paper lays out opportunities to optimize PO production for safer and more efficient processes, higher quality products, and substantial time savings by using online process analysis instead of laboratory measurements.

As the determination of the exact content of individual glycerides in fats and oils is difficult and time-consuming, several fat sum parameters or fat indices are used for the characterization and quality control of fats and oils. Fats and oils are not only essential for cooking, they are also an important ingredient in pharmaceuticals and personal care products, such as ointments and creams. Consequently, several norms and standards describe the determination of the most important quality control parameters. This Application Bulletin describes eight important analytical methods for the following fat parameters in edible oils and fats:Determination of water content in accordance with the Karl Fischer method; Oxidation stability in accordance with the Rancimat method; Iodine value; Peroxide value; Saponification value; Acid value, free fatty acids (FFA); Hydroxyl number; Traces of nickel using polarography; Special care is taken to avoid chlorinated solvents in these methods. Also, as many of the mentioned methods as possible are automated.

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

Methods are described for the potentiometric analysis of the following bath components:Brass plating bath: copper, zinc, free cyanide, ammonium, carbonate, and sulfite.Bronze plating bath: copper, tin, and free cyanide.

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

This Application Bulletin gives an overview of the coulometric water content determination according to Karl Fischer.Amongst others, it describes the handling of electrodes, samples, and water standards. The described procedures and parameters comply with the ASTM E1064.

This Bulletin gives a survey of standard methods from the field of water analysis. You will also find the analytical instruments required for the respective determinations and references to the corresponding Metrohm Application Bulletins and Application Notes. The following parameters are dealt with: electrical conductivity, pH value, fluoride, ammonium and Kjeldahl nitrogen, anions and cations by means of ion chromatography, heavy metals by means of voltammetry, chemical oxygen demand (COD), water hardness, free chlorine as well as a few other water constituents.

The determination of the physical and chemical parameters as electrical conductivity, pH value, p and m value (alkalinity), chloride content, the calcium and magnesium hardness, the total hardness, as well as fluoride content are necessary for evaluating the water quality. This bulletin describes how to determine the above mentioned parameters in a single analytical run.Further important parameters in water analysis are the permanganate index (PMI) and the chemical oxygen deman (COD). Therefore, this Bulletin additionally describes the fully automated determination of the PMI according to EN ISO 8467 as well as the determination of the COD according to DIN 38409-44.

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

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.

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.

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 Process Application Note presents a method to closely monitor low levels of moisture in propylene oxide safely and reliably by using a single explosion-proof inline process analyzer.

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

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.

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.

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.

A safer way to monitor moisture content in crude distillation unit overhead fractions is with inline near-infrared spectroscopy using the 2060 The NIR-Ex Analyzer.

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

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

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.

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.

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

Cyanides are used in some industrial processes, but if not handled carefully, they could contaminate the wastewater. In an acidic or neutral environment, this contaminated wastewater can form highly toxic hydrogen cyanide gas. Furthermore, the cyanide salts could also poison the environment and enter the ground water system. Therefore, it is essential to monitor the content of cyanide in effluent water. Cyanides can be easily determined with a cyanide ion-selective electrode. This application note presents a method for cyanide analysis according to APHA Method 4500-CN and ASTM D2036.

One of the major sources of fluoride intake for humans comes from foodstuff, such as tea. Tea actually has one of the highest potentials to increase the daily fluoride intake. Excessive fluoride intake may lead to dental or skeletal fluorosis. The World Health Organization does not recommend consuming water with a fluoride content higher than 1.5 mg/L. In the presented method according to DIN 10807, the fluoride content can be assessed quickly with an ion selective electrode.

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.

Polyurethanes are a class of synthetic polymers formed by reacting liquid di/polyisocyanates and polyols with a catalyst and various additives in a reactor. Polymer properties are modified with stepwise additions of these chemicals at different points in time depending on whether the process has reached an equilibrium. NCO functional groups from unreacted isocyanates must be quenched at the end for a finished product, and this parameter must be known to determine the proper chemical mixing ratio. A fast, non-destructive real-time measurement of %NCO can be obtained by using NIR spectroscopy with a probe seated directly in the reactor.

This Process Application Note presents a method to accurately monitor low levels of moisture in tetrahydrofuran (THF) in «real-time» safely, reliably, and optimally with a 2060 The NIR Analyzer from Metrohm Process Analytics. Due to the hazardous and hygroscopic nature of THF, a single explosion-proof inline process analyzer is the preferred solution for industries to reduce chemical treatment, improve product quality, and increase profits.

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.

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

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.

Groundwater contains many minerals, but can be contaminated by sodium-rich leachate from landfills. Accurate Na determination in water is possible following AOAC 976.25 using the Na-ISE.

Rapid inline monitoring of the major SC1/SC2 bath constituents is possible with reagent-free near-infrared spectroscopy, e.g., the 2060 The NIR-R Analyzer.

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

This Process Application Note presents a way to closely monitor multiple parameters simultaneously during the dioctyl terephthalate production process with 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.

This study demonstrates that near-infrared spectroscopy (NIRS) provides a fast, reagent-free method for determining salt content in ready-to-eat pickled foods. Salt content is a critical quality and safety parameter in the production of pickled vegetables and must be monitored throughout processing and in the final product. Although NaCl exhibits no characteristic NIR absorption bands, salt-induced changes in water absorbance bands enable its quantification by NIRS.

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.

Raman spectroscopy is a fast alternative method to detect phosphate and sulfate species in solution for optimized phosphorus fertilizer production and improved product quality.

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.

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

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.

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

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.

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.

Monitoring organic additives in copper plating baths is crucial. The 2060 CVS Process Analyzer optimizes copper electroplating by providing precise bath control.

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.

The size of the indigo molecule makes it difficult to dye synthetic fibers, but the large pores of cellulose (such as in cotton) accept it readily. Indigo is insoluble in water, so it must first be reduced to the water-soluble leuco-indigo form by sodium hydrosulfite in a strong alkaline bath. Good circulation within the bath is imperative for consistent dye coverage, but care must be taken not to introduce any oxygen. Fabrics must be oxidized between dips in the dye bath in order to set the indigo within the pores of the fibers, but multiple dips are necessary for darker, uniform coverage. Many parameters need to be monitored and controlled to ensure high quality of the end product: the pH value for proper NaOH (alkali) dosage, the concentrations of both hydrosulfite and indigo, as well as the temperature of the bath and even the redox potential.

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

Monitor adsorbable organic halogens (AOX) in water using combustion ion chromatography (CIC) for precise analysis of AOCl, AOBr, AOI, and total AOX.

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

Higher antioxidant levels mean longer product viability. The 892 Professional Rancimat determines antioxidant content in many products using a linear regression method.

Raman spectroscopy with PLS modeling enables rapid, accurate, nondestructive quantification of the total phosphate content in solution with minimal sample preparation.

In this note, we use a model drug, acetaminophen, to demonstrate the capability of QTRam® to quantify low concentrations of API in compressed tablets.QTRam® is a compact transmission Raman analyzer designed specifically for content uniformity analysis of pharmaceuticals in solid dosage forms.

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

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>.

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.

Mercaptans in fuels are corrosive and regulated at trace levels. SERS enhances Raman signals to enable their accurate detection and quantification below standard LODs.

Thermal power plants require enormous amounts of water, using high purity steam at high pressure to rotate turbines. A separate cooling water circuit is implemented, which helps to form a vacuum when the steam condenses after the turbines. Maintaining this vacuum with optimal condensation parameters is critical for the power plant efficiency. The copper condensers are susceptible to corrosion by ammonia, leading to an upper limit of 2 mg/L NH3 set by EPRI in cooling water. Small cracks in the condenser combined with the large pressure differential between the steam circuit and the cooling water circuit will contaminate the high purity water in the boiler, causing major problems and necessitating a shutdown for plant maintenance. Monitoring NH3 online in cooling water with a process analyzer can signal early problems in a plant before significant intermediation is necessary.

Boric acid is growing in demand for various industrial applications, but requires a more cost-efficient and environmentally friendly production process. This Application Note describes the performance of a Raman process analyzer (PTRam) when measuring low-concentration boric acid and sodium sulfate solutions (<100 mg/L) during boric acid production.

Etching is a vital process in semiconductor fabrication, involving the chemical removal of layers from the wafer substrate. Strict quality control measures are necessary to determine acid etchant concentrations in mixed acid solutions (e.g., SPM, DSP, or DSP+), critical for optimizing etch rate, selectivity, and uniformity during multiple wafer etching steps. This application presents a method to measure sulfuric acid and hydrogen peroxide in etching baths simultaneously using Raman spectroscopy with the PTRam Analyzer from Metrohm Process Analytics.

The 2060 XRF Process Analyzer continuously monitors elemental concentrations online within zinc-nickel electroplating baths to precisely guide chemical dosing.

In power plants, corrosion is the greatest enemy. If corrosive impurities are present in the circuit streams (e.g., chlorides and hydroxides), deposition of an insulating layer of scale on the heat transfer surfaces occurs, resulting in costly and critical downtimes. To ensure high throughput of power plants, online analysis of critical parameters such as sodium is highly advantageous for safety, protection, and process optimization. With the 2035 Process Analyzer from Metrohm Process Analytics, operators gain the information they need to accurately identify trends, reduce downtimes, and address operational issues before costly problems arise.

This Application Note explains how the 2060 XRF Process Analyzer enables real-time chemical monitoring of copper, tin, and zinc concentrations in white bronze plating baths.

Combustion ion chromatography (CIC) measures AOX (adsorbable organically bound halogens, i.e., AOCl, AOBr, AOI) and AOF as well as CIC AOX(Cl) according to EN ISO 18127.

Advances in polymeric membranes and screen-printed technologies have enabled miniaturized, portable potentiometric sensors ideal for point-of-care analysis.

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.