Application Finder

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

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

Complexing agents such as EDTA are used in soaps and other detergents in order to remove unwanted metal ions and to lower water hardness. The EDTA content in soaps and detergents can be determined using potentiometric titration with copper sulfate as titrant and the Cu-ISE as electrode.

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

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

Vitamin C is an important antioxidant included in milk powder. The double Auring electrode provides an excellent titration curve when using 2,6-dichlorophenolindophenol (DPIP) as titrant and is easy to clean.With the OMNIS system, a fast and accurate determination of vitamin C in milk powder by a bi-voltametric titration is realized.

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

The quantity of hydrolyzable chloride in epoxy resins has an influence on their reactivity and on the properties of the epoxy coating obtained.Rapid and accurate determination is possible with an OMNIS system using potentiometric titration with the dAg ring electrode and silver nitrate as the titrant.

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

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

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

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

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

For titrations in low conducting media (e.g., non-aqueous titrations) the potentiometric indication can be disturbed by interfering signals. When differential amplification is used, these signals are measured by both the measuring electrode and the reference electrode and thus neutralized. It is therefore possible to obtain smoother titration curves and more reproducible results.This Application Note describes the potentiometric determination of the acid number and base number in used motor oil by the differential amplification using a fully automated OMNIS system.

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

The bromine number is an important parameter for the determination of aliphatic C=C double bonds in petroleum products. The bromine number is usually determined using electrochemical titration at 5 °C, where the bromine is generated in situ from a bromide/bromate solution. For the titration, a solvent mixture of glacial acetic acid, methanol, and chloroform is used. In this Application Note, the toxic chloroform was replaced with diethyl carbonate.

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

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

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

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

The total iron content in iron ore plays a central economic role for mining companies. The higher the iron content in the ore, the more profitable the mining operation. Therefore, a fast and accurate analysis is important to determine the most profitable areas to work.The iron ore is dissolved in hydrochloric acid at 80 °C. Afterwards, the iron is quickly and accurately determined by potentiometric titration using the Pt-ring electrode and potassium dichromate as titrant.

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

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

The knowledge of the exact silver content of silver allows used for jewelry is very important to ensure the quality of jewelry. Therefore, the determination procedure is regulated internationally and nationally. A common approach is the titration with potassium bromide after an acidic digestion of the silver using a silver electrode for indication.

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

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

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

Kjeldahl method is used to determine the nitrogen content in organic and inorganic samples. Kjeldahl consists of three steps: digestion, distillation, and titration. During the catalytic digestion step, organic 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.

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

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

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

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

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

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

The presence of acidic components in volatile solvents could be a result of contamination, decomposition during storage, distribution or manufacture. An increased acid content in solvents could lead to a variety of problems like shorter storage stability or chemical corrosion. Using the Optrode for indication, the acidity is determined by photometric titration with sodium hydroxide as titrant and phenolphthalein as indicator. If the volatile solvent is water soluble, it is dissolved in deionized water, if not, it is dissolved in carbon-dioxide free ethanol.

The permanganate index (PMI) is a sum parameter that indicates the total load of oxidizable organic and inorganic matter in water. The substances concerned are mainly humic materials/acids that are primarily formed when dead organic material present in soil is further broken down and released into water sources. As it is an indicator of the water quality, testing of the PMI for drinking water is obligatory in many countries.For the determination, it is necessary to heat the stabilized water sample to 95 °C and higher for a stipulated time. Afterwards, the amount of permanganate that has remained after the reaction with the sample is determined titrimetrically. This sample preparation step requires considerable manual effort.In this Application Note, a fully automated procedure for the determination of the PMI according to GB/T 11892 is described, including all sample preparation steps. The gains in productivity because of a reduced manual workload are considerable.

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.

The bromine index is an important parameter for the determination of aliphatic C=C double bonds in petroleum hydrocarbons. For the titration, a solvent mixture of glacial acetic acid, methanol, and dichloromethane is usually used.In this Application Note, the chlorinated solvent in the solvent mixture was replaced with toluene, resulting in a more environmentally beneficial method in comparison to ASTM D2710 and IP 299.

The bromine index is an important quality control parameter for the determination of aliphatic C=C double bonds in aromatic hydrocarbons and is thus a measure for the presence of aliphatic unsaturation in these materials. In situ generated bromine reacts with the aliphatic double bonds. When the titration is finished an excess of free bromine causes a sudden change in the measured potential thus indicating the equivalence point.

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.

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

The analysis of the reductants, free and total sulfurous acid, pH and total acidity of wine can be performed fully automated on an OMNIS system based on the directive OIV-MA-AS323-04B, OIV-MA-AS313-01 and OIV-MA-AS313-15.Added components like SO2 have preserving properties and affect the microbiological environment (anti-microbacterial and enzyme-deactivating), they trap fermentation byproducts such as acetaldehyde and suppress a coloring into brown. The bound and free sulfurous acid are in an equilibrium with each other and can be determined via iodometric titration. Iodometric titration is also the method of choice to quantify other reductants, such as dyes, tanning agents, degradation products of carbohydrates and ascorbic acid. Finally, the acidity of wine is an important quality parameter, which affects the color and taste of wines. The total acidity and the pH of wine can be determined on the same system. Hence, Metrohm offers an all-in-one solution for the analysis of these mentioned key parameters.

The FOS/TAC value, sometimes referred to as VFA/TA, is a meaningful parameter for assessing both the current condition and the development of anaerobic digestion processes in a digester of a biogas plant. Knowledge of this value can help decrease the risk of acidification problems, which can result in a costly crash of the entire digestion process. Therefore, an accurate and reliable determination of the FOS/TAC value is important for both efficient and cost-effective production operations. This value is determined by an acid-base titration. Using the Eco Titrator from Metrohm equipped with an Ecotrode plus electrode, a reproducible and accurate determination of the FOS/TAC value is possible.

Water treatment with ozone (O3) is a common procedure for the disinfection of swimming pools. It is important that a sufficient but not excessive amount of O3 is produced to disinfect the water. Otherwise, the remaining ozone could enter the swimming water, which could irritate the respiratory system or the skin of bathers.Ozone is also used in drinking and waste water treatment because it is significantly more effective than chlorine at inactivating or killing viruses and bacteria. This application note describes a method to determine the ozone concentration in water by potentiometric titration according to DIN 38408-3.

Nitrogen-based compounds are widely distributed in the environment and are essential growth nutrients for photosynthetic organisms. Therefore, it is important to monitor and control the amount of nitrogen compounds which are released into the environment.In this Application Note, a method to determine the nitrogen content in water by Kjeldahl digestion and distillation followed by a photometric or potentiometric titration according to ASTM D3590 is presented. The universality, precision, and reproducibility of the Kjeldahl method have made it the internationally recognized method for e.g. estimating the protein content in many matrices and it is the standard method to which all other methods are judged against.

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.

Lithium nitrate is an oxidizing agent used in the manufacture of red-colored fireworks and flares. In addition, the lithium nitrate trihydrate compound absorbs heat well and can be used for thermal energy storage. Since lithium nitrate is a hygroscopic substance, its purity must first be verified before it is used for synthesis or other applications. The purity assay is done by a fully automated precipitation titration between lithium and fluoride in an ethanolic solution. The benefit of titration is that the lithium nitrate does not need to be diluted after dissolving in ethanol as with other techniques such as ICP-MS.

Sodium hypochlorite and sodium chloride can be effectively use as disinfectant for water and surfaces. The World Health Organization (WHO) recommends, depending on the application, concentrations in disinfectants of 1000 mg/L to 5000 mg/L NaOCl and up to 200 g/L NaCl.This Application Note demonstrates a reliable method to determine the hypochlorite and sodium chloride content in disinfectants by two subsequent argentometric titrations in the range recommended by the WHO.

The lithium-ion battery market is continuously growing due to the tremendous demand for battery powered consumer products. So-called «NCMs», a mixture of nickel, cobalt, and manganese oxides, have been gathering interest as cathode materials, replacing traditional compounds like cobalt oxides.Quality analysis of the post-sintered materials or recycled batteries can be performed by titration, as demonstrated in this Application Note. A fully automated analysis of the corresponding metals can be performed with OMNIS and its pipetting equipment.

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.

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.

This Application Note shows the automatic pH adjustment of a mixture of acetonitrile, water and amine using a Metrohm titrator.

Traditional Chinese medicine (TCM) remedies are gaining popularity in other cultures. In some TCM, sulfur dioxide (SO2) is used as a preservative, antioxidant, and disinfectant. The products are treated by sulfurization with SO2 gas. However, sulfur dioxide is a very poisonous gas. Global health authorities have set strict limits for the content of SO2 in products. It is therefore of crucial importance to determine the sulfur dioxide content to comply with these limits. In this well-suited method, the SO2 content in different natural TCM products are analyzed reliably and accurately according to ISO 22590 using the Eco Titrator equipped with an Optrode and sodium hydroxide as titrant.

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.

Coagulation and flocculation are an essential part of treating both drinking water and wastewater. Aluminum salts such as aluminum sulfate and polyaluminum chloride (PAC) are often used for this purpose. For the precise application and exact dosage of the flocculant, it is important to accurately determine its aluminum content. In this Application Note, the aluminum content is accurately and reliably analyzed based on ABNT NBR 11176 using the 859 Titrotherm equipped with a Thermoprobe HF and sodium fluoride as titrant.

Many of the key factors that influence coffee taste correlate with chemical properties that can be measured. These include pH, titratable acidity, refractive index, and caffeine. Historically, many of these analyses have included long, manual sample preparation processes using the time-consuming, liquid chromatography (LC) technique. This Application Note looks at a faster, simpler, alternative method for analysis of key quality parameters in coffee using a single titration platform: OMNIS.

Boehm titration is a quantitative analysis of functional groups on the surface of carbon materials based on their reactions with basic solutions of NaHCO3 (pKa = 6.4), Na2CO3 (pKa = 10.3), and NaOH (pKa = 15.7). This is a cost-efficient method that gives absolute values with high precision of the accessible, mainly oxygen-containing functional groups on the surface. Originally, Boehm titration was developed for carbon materials like conductive carbon black (CCB), activated carbon, porous carbon, and graphite. Modern carbon-based materials like graphene, graphene oxide (GO), or carbon nanotubes can also be analyzed this way.

Sodium lactate is a salt form of lactic acid used in many regulated industries—therefore an accurate determination of the lactate content is required and is already covered in several norms. One such monograph by the US Pharmacopoeia (USP) results in high accuracies and well-defined titration curves but uses titrants and solvents that are more costly than necessary. In comparison, the presented modified method from Metrohm requires a 1:1 mixture of water and acetone and uses aqueous hydrochloric acid as titrant, resulting in an estimated cost reduction of 40% per titration compared to the USP method (USP–NF 2021, Issue 2). Furthermore, the time needed for each analysis is reduced to just 12% of the USP method (excluding blank determination). This Application Note presents both methods to determine lactate content and shows the results obtained on an 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.

About 20% of our sugar comes from sugar beet crops, mostly grown in Europe and the U.S. where the climate is temperate, whereas the other 80% is produced from sugar cane in tropical areas. Lime salts and pH are very important factors which are controlled during the sugar manufacturing process. Complexometric titration is often used to determine the concentration of lime salts in such kinds of samples. This Application Note presents a more robust method for determining calcium compounds in sugar beet juice. Subjectivity of color change determination is eliminated by using an ion selective electrode (ISE).

Mannitol content determination is an important aspect of quality control in the pharmaceutical and food industries. Selective oxidative cleavage can be used to quantify the amount of 1,2-diol groups in the analyte. Determining the 1,2-diol content by iodometric titration can be fully automated for the most accurate results using an automated titrator and the dPt Titrode from Metrohm.

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.

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.

Titration is an accurate and precise method that can be used to determine the pyrophosphate content in aqueous products. The OMNIS Titrator equipped with a dUnitrode delivers reliable determinations.

This Application Note compares the OMNIS Titrator and 888 Titrando for determinations of nitric acid, phosphoric acid, and acetic acid in an aluminum etching bath, as well as the determination of tetramethylammonium hydroxide (TMAH). Identical analysis parameters were used, showing that OMNIS delivers results on par or even better than with other established titration systems.

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

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.

Alkalinity defines the acid-binding capacity of natural water. A distinction is made between total alkalinity (m-value) and carbonate alkalinity (p-value). This Application Note presents the determination of pH and alkalinity in water with a titration method conforming to EPA 310.1, Standard Methods 2320 B (Titration Method), ASTM D1067, EN ISO 9963-1, and EN ISO 9963-2.

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.

The total acid number (TAN) is an important parameter for assessing the acidity of oils and fuels. This Application Note determines TAN using conductometric titration.

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

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.

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

The acid value of fatty acid methyl esters (FAME) like biodiesel can be determined according to EN 14104 using photometric titration with OMNIS and the Optrode.

Purity of rare earth elements (REEs) can be determined by absolute complexometric titration with xylenol orange (ISO 23597). This approach achieves around 100% recovery, eliminates the need for calibration, and offers higher accuracy and reproducibility than techniques such as AAS (atomic absorption spectroscopy). Photometric titration with the Optrode M2 offers adjustable wavelength detection, providing a fast, precise, and cost-effective alternative to other conventional methods.

Rare earth elements (REEs) are critical materials whose deposit viability and processing streams require accurate mass-fraction determination during ore dissolution and purification. This Application Note describes a rapid potentiometric back-titration using a copper ion-selective electrode (Cu-ISE) that enables selective quantification and partial separation of REEs in complex matrices with near-quantitative recovery. As an absolute, flexible, and cost-effective method with ICP-compatible sample preparation, back-titration is well suited both as a reference technique and for rapid on-site analysis.

The rapid growth of the Earth's population has led to massive increases in the consumption of energy and resources and in the production of consumer products and chemicals. It is estimated that 17 million chemical compounds are currently on the market, of which 100,000 are produced on a large industrial scale. Many of these enter the environment. This leads to a demand for sensitive analytical procedures and high-performance analytical instruments.pH value, conductivity and oxygen requirement are important characteristics in water and soil analysis. The first two of these can be determined rapidly; for the third, the titration that is used is also the one used in numerous single determinations. This article describes several important standard-compliant determinations in water and soil analysis.

The present article addresses the theory, practical aspects and troubleshooting of potentiometry.

Many refiners look at discounted opportunity crudes as a means to improve their margin spread. The varieties of these cheap crude oils on the market are growing in number, but they have hidden risks for the purchaser caused by factors such as high naphthenic acid and sulfur content. Sulfur compounds and naphthenic acids are among the substances that contribute to the corrosive nature of crude oils and petroleum products. This is why the risk of corrosion is increased when processing crude oils with high naphthenic acid and sulfur content. The refiner must balance the cost benefit versus the risk and the cost of corrosion control when processing these crudes. A reliable acid number determination is a crucial part of corrosion control. Guest authors Bert Thakkar, Bryce McGarvey, and Colette McGarvey of Imperial Oil and Larry Tucker and Lori Carey of Metrohm USA were involved in the development of the new ASTM Method D8045 for acid number determination. Here, they report on the method and how it came to be.

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

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.

This white paper summarizes the advantages and benefits of automated titration in comparison to manual titration. The increase in accuracy and precision of measurements as well as significant time and cost savings are discussed.

The acid number (AN) is a measure for the quality of oils and their potential to enhance corrosion. When analyzing fresh, unused oils, the AN is used to ensure the specified quality from the manufacturer, whereas for used oils the AN is determined to observe its increase until a critical level is reached. Although it is generally assumed that the AN correlates to the corrosive potential of the oil, this is not exactly correct, as it is the change of the AN value which indicates this issue. Therefore it is necessary to determine the AN on a regular basis.Several standards already exist to determine AN via titration methods, however it is also possible to measure this parameter via spectroscopic (NIRS) methodology. No matter which technique you choose, Metrohm has you covered with high-performance instruments suitable for these published norms.

The FOS/TAC value is an important characteristic to assess the status of the fermenter before costly problems arise. The new Eco Titrator from Metrohm allows the determination of this quotient in a fast, cost-efficient, and precise way.

Agriculture at significant scale without fertilizers is no longer possible in the modern world. To grow a sufficient amount of produce for nearly 8 billion people as well as for domesticated animals and industrial uses, fertilizers of different nutrient compositions are available to cater to the unique needs of various soil types. Information on the fertilizer’s composition (e.g., total nitrogen, phosphorus, and potassium) is available to help select the ideal fertilizer for a specific soil. Conventionally these constituents are determined either gravimetrically (e.g., phosphorus, potassium, or sulfate) or with ICP-OES (e.g., phosphorus or potassium). These methods either have the disadvantages of long analysis times combined with laborious sample preparation (gravimetry), or require expensive instrumentation with high running costs (ICP-OES). This White Paper elaborates how thermometric titration is a fast and inexpensive alternative method to provide information on the content of various nutrients in different fertilizers.

This white paper summarizes the steps involved in converting an existing manual titration procedure to semi-automated or automated titration procedures. It discusses topics such as selecting the right electrode and titration mode. For a better understanding, the discussion topics are illustrated with three examples.

The objective of validation of an analytical procedure is to demonstrate that it is suitable for its intended purpose. Recommendations for the validation of analytical methods can be found in ICH Guidance Q2(R1) Validation of Analytical Procedures: Text and Methodology and in USP General Chapter <1225> Validation of Compendial Procedures. The goal of this white paper is to provide some recommendations for the validation of titration methods.

White paper on monitoring corrosion and the benefits of online or inline chemical analysis over manual sampling and offline laboratory methods for corrosion monitoring. Online and inline process application solutions for corrosion prevention with related application notes for further information are presented.

Lithium-ion batteries (LIBs) are the most common rechargeable options available today. Production of LIBs needs to follow stringent quality standards.

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 White Paper gives an overview of the energy-intensive nitrification process that converts ammonia into less harmful nitrogen compounds at wastewater treatment plants (WWTPs). It displays the results from a field test at a WWTP, showcasing the positive influence of single-method process analyzers on the efficiency of the nitrification process.

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