Application Finder

Formate, acetate, propionate, and butyrate in addition to standard anions are determined in a coal extract. To improve the separation of the early eluting organic acid anions, a Dose-in Gradient is applied. Due to the limited sample volume available, Metrohm intelligent Pick-up Technique (MiPuT) is also utilized.

Determination of anions in solder paste after alcoholic extraction using anion chromatography with direct conductivity detection.

This Application Note presents ion chromatography as a precise method to analyze anions in beer as well as cations with non-suppressed conductivity. Automation with Inline Ultrafiltration is also discussed.

The Metrosep A Supp 5 microbore anion column is available in 150 and 250 mm lengths. For the two columns, the run times for separating the 7 standard anions are 20 and 29 minutes. In addition to the good separation properties and the short running times, microbore columns use approximately 75% less eluent than does their 4 mm counterpart.

Anions in diesel, especially biodiesel, may cause harmful deposits in the engine. Determination with ion chromatography requires the transfer of the diesel anions into an aqueous solution, injectable to the IC. A typical method to transfer the anions into water is via Inline Extraction with subsequent Inline Dialysis prior to the injection (see AN-C-101 for a respective analysis of cations). In the actual Matrix Elimination method, diesel diluted with isopropanol is injected into an isopropanol stream and passed through a preconcentration column. Isopropanol washes off the diesel, and a subsequent rinsing step with ultrapure water removes excess isopropanol.

Determination of 21 anions and organic acids using anion chromatography with conductivity detection after chemical suppression and applying a high pressure gradient.

4-Hydroxybutyrate (GHB) is numbered among the hydroxycarboxylic acids and is used as a psychoactive drug which is illegal in many countries. GHB can be determined through anion chromatography with suppression. GHB can be separated from the standard anions and the organic acid anions glycolate, acetate and formate on the Metrosep A Supp 16 - 250/4.0 column and under the conditions specific in this Application Note.Key words: Liquid Ecstasy, KO drops

The high-capacity suppressor MSM-HC allows to run analyses with high eluent concentrations, e.g., sodium hydroxide eluents. The determination of anions in washing powder is a typical example where the high pH of NaOH is required for the separation of polyphosphates.

Hydrogen peroxide is used as a cleaning, oxidizing and bleaching agent. Depending on its purity, it may contain inorganic anions as well as organic acid anions, such as oxalate, phthalate, and dipicolinic acid. Dipicolinic acid is a complexing agent that binds transition metal cations and is sometimes added to increase the stability of hydrogen peroxide.

Cleanliness is indispensable in electronics production. Ionic contaminations in particular lead to a drastic worsening of the quality of the printed circuit boards. The present Application Note describes the determination of anions on printed circuit board surfaces. The intelligent Partial Loop Injection Technique (MiPT) used for this purpose permits the determination of cations and anions in the same sample. The determination of the cations is described in AN-C-149.

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

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

Measures to monitor or prevent corrosion are crucial in nuclear power plants, where significant risks to health and safety can occur if corrosion is left unchecked. Anions corrode metals under high temperature and pressure, therefore their concentrations must be monitored at all times. The analytical challenge in the primary circuit is detection of anions in the μg/L range alongside gram quantities of boric acid and lithium hydroxide. Precise, reliable trace analysis requires the method to be automated as much as possible. The 2060 IC Process Analyzer from Metrohm Process Analytics can measure several anions from a single injection, with combined Inline Preconcentration and Inline Matrix Elimination to measure low anion concentrations precisely and reliably time after time.

EN ISO 10304-1 is one of the most important standards for the determination of the seven standard anions in water samples. Many other standards refer to EN ISO 10304-01 if anion determination by IC is required. This standard asks for a membrane filtration for samples to avoid bacteria and solids, if required. This application shows the determination of anions according EN ISO 10304-1 applying Inline Ultrafiltration. This setup avoids tedious manual sample filtration and handles any samples fully automatically.

Analysis of sodium hydrogen carbonate (also known as sodium bicarbonate) for anionic contaminants is critical due the large amount of CO2 formed during suppression. Even applying sequential suppression does not completely remove the interferences due to the carbonate peak. The introduction of Inline Neutralization applying the Sample Preparation Module (SPM) with subsequent CO2 removal with the MCS (Metrohm CO2 Suppressor) prior to the injection solves the problem. After this pretreatment, the sequentially suppressed sample is analyzed without issues.

Determination of fluoride, chloride, nitrite, nitrate, and sulfate in rainwater using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, bromide, nitrate, phosphate, and sulfate in dimethylacetamide using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrate, phosphate, sulfate, silicate, and hexafluorosilicate (calculated) using anion chromatography with conductivity detection after chemical suppression and subsequent UV/VIS detection with post-column reaction (see AN U-48). Hexafluorosilicate is hydrolyzed into fluoride and silicate. Both anion concentrations can be used for the calculation of the SiF62- concentration.

Determination of fluoride, chloride, nitrate, sulfate, and oxalate in a perfluorocarbon material using anion chromatography with conductivity detection after chemical suppression.

«High ionic water» is typically water containing a high concentration of chloride (e.g. seawater, brine), but this also describes water samples resulting from petrochemical processes. Due to the high chloride concentrations, the conductivity determination of minor ionic components is limited. Thus, minor anions like nitrite, bromide, and nitrate can elute under or on the tail of the large chloride peak, and their detection in low concentrations is hampered. However, combining conductivity and UV/VIS detection as described in ASTM D8234 enables the determination of anions that are UV active. Chloride does not interfere in this situation. The described technique enables the interference-free simultaneous determination of trace anions besides high chloride content.

Ultrapure chemicals are required in the semiconductor industry. Ionic impurities may lead to compromised products. This application describes the determination of anionic impurities in semiconductor grade 28% ammonium hydroxide solution. To avoid matrix disturbances, Inline Neutralization and Inline Preconcentration with Matrix Elimination needs to be applied.

Determination of chloride, nitrite, nitrate, phosphate, sulfate, trimeta-, and pyrophosphate in tripolyphosphate using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

Fast IC means a high sample throughput. This is attained with short columns, relatively high flows and strong eluents. Here standard anions are determined within three minutes on the Metrosep A Supp 10 - 50/4.0.

Determination of chloride, nitrite, nitrate, and sulfate in betaine using anion chromatography with conductivity detection after chemical suppression.

Organic acids in wine are omnipresent in winemaking. Some of them are present already in the grape while others appear during fermentation. The sum of organic acids and their composition have a direct influence on the taste of the respective wine. In this application a wine is tested for minor organic acids, especially shikimic and iso-citric, besides typical acids and anions. The separation is performed by anion chromatography applying a low-pressure gradient to achieve the required selectivity.

Retention of thiosulfate, thiocyanate and perchlorate is strong on the Metrosep A Supp 5 - 250/2.0 column. A shorter run time for the separation of the anions mentioned along with standard anions is achieved using a low-pressure gradient.

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

Anionic surfactants can be titrated with cationic surfactants and vice-versa. The Bulletin describes a multitude of substances that can be determined in this fashion and specifies the respective working conditions and parameters. In contrast to the classic two-phase titration in accordance with Epton, the titration with the anionic and cationic surfactants electrodes can be performed without chloroform. Furthermore, the equivalence point of the titration is difficult to determine in some cases with the Epton method and the titration cannot be automated.In many cases, a surfactant ISE is a remedy that is both environmentally friendly and suitable here. It was developed specially for application with potentiometrically indicated surfactant determinations.

Determination of chloride, nitrite, bromide, nitrate, and sulfate in inositol using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, sulfite, sulfate, oxalate, and thiosulfate in lignin using anion chromatography with conductivity detection after chemical suppression.

This White Paper focuses on selected IC-MS applications for the straightforward identification and quantification of organic acids and inorganic anions in different matrices.

Determination of fluoride, chloride, nitrate, sulfite, phosphate, and sulfate in wastewater using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrite, nitrate, benzoate, and sulfate in PVC film using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrate, phosphate, and sulfate in a borate effluent using anion chromatography with conductivity detection after chemical suppression.

Quality and process control of biofuels require straightforward, fast and accurate analysis methods. Ion chromatography (IC) is at the leading edge of this effort. Traces of anions in a gasoline/ethanol blend can accurately be determined in the sub-ppb range after Metrohm Inline Matrix Elimination using anion chromatography with conductivity detection after sequential suppression. While the analyte anions are retained on the preconcentration column, the interfering organic gasoline/bioethanol matrix is washed away.Detrimental alkali metals and water-extractable alkaline earth metals in biodiesel are determined in the sub-ppm range using cation chromatography with direct conductivity detection applying automated extraction with nitric acid and subsequent Metrohm Inline Dialysis. Unlike high-molecular substances, ions in the high-ionic strength matrix diffuse through a membrane into the low-ionic water acceptor solution. In biogas reactor samples, low-molecular-weight organic acids stem from the biodegradation of organic matter. Their profile allows important conclusions concerning conversion in the anaerobic digestion reaction. Volatile fatty acids and lactate can be accurately determined by using ion-exclusion chromatography with suppressed conductivity detection after inline dialysis or filtration.

Process water from flue gas desulfurization mainly contains sulfite and sulfate. Besides these two main components, other sulfur species may be formed in the process. This application describes the determination of such late-eluting sulfur species with ion chromatography applying a Dose-in gradient. The applied gradient profile enables the resolution of amidosulfonate, dithionate, and imidodisulfonate besides thiosulfate, thiocyanate, major anions, and acetate.

Water of the water-steam cycle of boiling water reactors (BWR) needs to be free of corrosive anions. Analyzing these trace anions allows the parallel determination of chromate, which is a potential corrosion product. Automated sample preparation includes variable Inline Preconcentration (MiPCT) and automatic calibration with a single multi-ion calibration standard.

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

Determination of 1 (3) µg/L of chloride, nitrite, bromide, nitrate, phosphate, and sulfate after direct injection using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrate, phosphate, sulfate, trimetaphosphate, and tripolyphosphate in tetrasodium pyrophosphate using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrite, nitrate, and sulfate in an effluent sample using anion chromatography with direct conductometric detetction.

Determination of fluoride, chloride, phosphate, and sulfate in boric acid using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, phosphate, and monofluorophosphate in glutamine monofluorophosphate using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrate, and sulfate in corrosion powder using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, phosphate, and sulfate in beer wort using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, nitrate, phosphate, and sulfate in an etching reagent using anion chromatography with conductivity detection after chemical suppression.

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

Determination of fluoride, chloride, nitrite, nitrate, phosphate, and sulfate in cooling water using anion chromatography with conductivity detection after chemical suppression.

Determination of phosphate, HEDP (etidronic acid), and pyrophosphate in a biocide sample using anion chromatography with conductivity detection after sequential suppression.

Determination of bromoacetate, methanesulfonate, chloride, phosphate, and sulfate in an acidic cleaning solution using anion chromatography with conductivity detection and chemical suppression.

Monoethylene glycol is used for dehydration of the natural gas before liquefaction and has to be checked for its purity on routine basis. Inorganic anions and their corresponding acids are corrosive. Therefore, they have to be kept at minimum level. The separation is performed on a microbore Metrosep A Supp 16 - 250/2.0 column and quantified by conductivity detection after sequential suppression.

Determination of fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfite, and sulfate in river water using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfite, sulfate, and thiosulfate in colored liquors using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, acetate, formate, chloride, nitrite, nitrate, phosphate, and sulfate impurities in syringe filters using anion chromatography with conductivity detection after sequential suppression.

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

Determination of chloride, nitrite, nitrate, phosphate, and sulfate in a meat extract (Na2B4O7) after Carrez clearing using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrate, phosphate, sulfate, and oxalate in human urine using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

Product consistency and quality is of utmost importance to winemakers. This wine analysis evaluates nutrients and other ionic ingredients, which could potentially have deleterious effects on efficiency and production during the fermentation process. Inorganic and organic anions as acetate, chloride, phosphate, malate, sulfite, tartrate, sulfate, and oxalate are separated and quantified on a Metrosep A Supp 10 - 100/4.0 applying Inline Ultrafiltration and conductivity detection.

Ionic liquids, also denominated as «designer solvents», are organic salts that are liquid at low temperatures. They are powerful solvents, conduct the electric current, and are therefore used in many applications. Anions, in particular halogenides, are common byproducts in the manufacturing of ionic liquids. Therefore, their concentration has to be controlled.

Determination of lactate, formate, chloride, phosphate, and sulfate in orange juice using anion chromatography with conductivity detection after chemical suppression and inline sample preparation by dialysis.

Determination of chloride, bromide, and sulfate in seawater using anion chromatography with conductivity detection after chemical suppression.

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.

Determination of fluoride, chloride, nitrite, nitrate, and sulfate in soil eluates using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrite, bromide, nitrate, and sulfate in surface water using anion chromatography with conductivity detection after chemical suppression.

Determination of acetate, chloride, nitrite, bromide, nitrate, phosphate, sulfate, oxalate, fumarate, and molybdate using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, chloride, bromide, nitrate, sulfate, and trifluoroacetate (TFA) in a peptide sample using anion chromatography with conductivity detection after chemical suppression.

The separation of short-chain organic acids from fluoride and chloride requires diluted eluents. These weak eluents, however, induce long retention times for divalent anions. Adding a stronger eluent later in the separation sequence by use of a Dose-in Gradient makes these anions elute more rapidly. Furthermore, the Dose-in Gradient offers the advantage of low equipment and technical expense.

Determination of formate, chloride, nitrate, phosphate, and sulfate in 20% TMAOH using anion chromatography with conductivity detection after sequential suppression and inline matrix neutralization.

Swimming pool water needs to be thoroughly disinfected and this is often accomplished with ozonization. This process can generate harmful oxyhalides, the concentration of which must be monitored. Here the separation and determination of oxyhalides as well as standard anions are carried out using a column of the Metrosep A Supp 5 - 250/4.0 type. Quantification takes place using conductivity detection in accordance with sequential suppression.

Determination of acetate, formate, chloride, bromide, and sulfate in toluene using anion chromatography with direct conductivity detection.

Metrohm Inline Neutralization is a well-established sample preparation technique for anion determinations in hydroxide solutions. The intelligent Partial Loop Injection Technique (MiPT) allows to calibrate the system with one single standard solution and to adjust the injection volume according to the anion concentrations in the sample. This method has been successfully applied to anion analysis in potassium hydroxide (50 and 85%) and in potassium carbonate solutions (83%).

Determination of fluoride, chloride, nitrate, phosphate, and sulfate in boric acid with sample preconcentration using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrite, bromide, nitrate, and sulfate in water for infusion solution production using anion chromatography with conductivity detection after chemical suppression.

Determination of glycolate, formate, chloride, nitrite, nitrate, phosphate, sulfate, and oxalate in engine coolant using anion chromatography with conductivity detection after chemical suppression.

Microbore columns with an inner diameter of 2 mm reduce the eluent consumption to about a quarter. Consequently, the detected peak areas of corresponding sample concentration are increased by a factor 4. In this report, the determination of anions in drinking water is described on a Metrosep A Supp 5 - 150/2.0 column.

The determination of anions in tap water is a simple IC application. Here it is used to present Metrohm's intelligent Pick-up Technique (MiPuT). MiPuT enables the injection of volumes of minimum size from very small sample quantities. In the present case, two volumes of 10 µL from a sample 100 µL in size are used for anion and cation analysis, respectively. The calibration takes place through the injection of various volumes of a single standard solution. AN-C-141 describes the corresponding cation determination.

Determination of chloride, nitrite, cyanate, azide, nitrate, chlorate, sulfate, thiocyanate, thiosulfate, and perchlorate in an extract of explosives using anion chromatography with conductivity detection after chemical suppression.

Traces of organic acids can be determined only with difficulty in the presence of high concentrations of standard anions, because their small peaks generally disappear under the larger peaks of the standard anions. A simple dose-in-gradient improves the separation: acetate and formate are baseline-separated from fluoride. Furthermore, oxalate elutes considerably less than sulfate. The separation takes place on a column of the Metrosep A Supp 7 - 250/4.0 type with subsequent conductivity detection following sequential suppression.

Determination of fluoride, formate, chloride, nitrite, bromide, nitrate, sulfate, oxalate, and molybdate in a coolant using anion chromatography with conductivity detection after chemical suppression and Metrohm Inline Dialysis.

This article describes a simple method for the determination of seven standard anions (fluoride, chloride, nitrite, bromide, nitrate, phosphate and sulfate) in accordance with US EPA Method 300 Part A. An IC system is extended to include Inline Ultrafiltration and Inline Eluent Preparation for the analysis.

Determination of fluoride, acetate, propionate, formate, butyrate, chloride, nitrite, bromide, nitrate, benzoate, phosphate, sulfate, malonate, and oxalate in an industrial process water using anion chromatography with conductivity detection after sequential suppression.

Determination of pyro-, trimeta-, and tripolyphosphate in the presence of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

Determination of fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate, oxalate, thiosulfate, iodide, and citrate in a standard solution using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

The Dose-in Gradient expands the standard IC system to a gradient system. Using isocratic elution for separating the oxyhalides and the anions containing sulfur is very time-consuming. An 800 Dosino and a T-piece are used to expand the isocratic system to a binary gradient system. This is shown in the example of the determination of the standard anions, in addition to chlorate, thiosulfate, thiocyanate, and perchlorate.

Determination of fluoride, chloride, nitrite, nitrate, and sulfate in a closed cooling water system using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, bromide, nitrate, phosphate, and sulfate in 20% NaOH after inline neutralization by cation exchange on the 793 IC Sample Prep Module using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, sulfate, maleate, oxalate, and fumarate in ink using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

Ion chromatography tackles difficult separation problems of various ionic species and typically works with conductivity detection. Mass detection as a secondary independent detector significantly lowers the detection limits and confirms the identity of analytes even when coeluting. This poster describes how the combination of IC-MS and automated sample preparation techniques cope with the analysis of anions and oxoanions in challenging matrices such as soil or explosion residues.

Determination of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate in water from an agricultural irrigation system using anion chromatography with conductivity detection after chemical suppression.

Electronic-grade nitric acid may not contain more than the slightest traces of anion contaminations (in the mg/L range). The ion chromatography determination of these kinds of anion traces requires not only a high-capacity column but also an eluent that allows the nitrate to be eluted by the column, although only after all of the other ions of interest have been eluted. This separation is achieved on a column of the Metrosep A Supp 16 - 250/4.0 type with the aid of a strong carbonate/hydrogen carbonate eluent.

Determination of formate, chloride, nitrite, phosphite, phosphate, sulfite, nitrate, and sulfate using anion chromatography with conductivity detection after chemical suppression.

Water of the primary cycle of pressurized water reactors (PWR) contains boron for neutron absorption. The high borate content interferes with the direct analysis of trace anions. Inline Neutralization combined with variable preconcentration and Inline Matrix Elimination (MiPCT-ME) allows to remove boron as boric acid before injection.

Determination of fluoride, chloride, nitrate, phosphate, and sulfate in surface water using anion chromatography with conductivity detection after chemical suppression; nitrite with electrochemical detection (conductivity and ELCD detectors in series).

Determination of iodide and thiosulfate in photographic process wastewater using anion chromatography with amperometric detection at the carbon paste electrode after chemical suppression.

ASTM D8234 describes the determination of anions in high saline water by applying suppressed conductivity followed by UV/VIS detection. This combination enables the determination of e.g. nitrite by UV detection. With conductivity detection, this quantification is not possible or difficult due to the very large chloride peak. The actual sample is a refining process liquid with a high chloride content. As the sample solution also contains organic material, Inline Dialysis is applied to protect the analytical column. The combination of the two detection modes and the Inline Dialysis option reduces manual sample preparation and substantially increases the accuracy of the analysis.

Determination of trace levels of chloride, nitrate, phosphate, and sulfate in a boiler feed water using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrite, bromide, nitrate, phosphate, sulfite, sulfate, and oxalate in a cooling lubricant using anion chromatography with conductivity detection and subsequent UV detection (see AN-U-047) after sequential suppression and Metrohm Inline Dialysis.

Qualitative determination of chloride, phosphate, and sulfate as well as chlorite, nitrite, chlorate, bromide, and chromate in urine using anion chromatography with conductivity detection after chemical suppression.

Determination of acetate, chloride, nitrite, nitrate, benzoate, phosphate, and sulfate using anion chromatography with conductivity detection after chemical suppression.

Determination of traces of fluoride, bromide, nitrate, phosphate, and sulfate using anion chromatography with conductivity detection after chemical suppression and subsequent UV/VIS detection.

Determination of fluoride, chloride, nitrite, selenite, phosphate, nitrate, sulfate, and selenate using anion chromatography with conductivity detection after chemical suppression.

Two-phase titration with potentiometric indication is a universal method for the determination of ionic surfactants in detergents. The results obtained are comparable to those with the classic two-phase titration in accordance with Epton (mixed indicator system disulfine blue / dimidium bromide). The present Bulletin addresses various parameters that could have an influence on potentiometric surfactant titration. The information provided makes it possible for the user to determine precisely the anionic surfactant content in practically all formulations.

Determination of fluoride, chloride, phosphate, and sulfate in sodium tetraborate using anion chromatography with conductivity detection after sequential suppression. Inline acidification is applied to convert tetraborate into boric acid which is not retained on the preconcentration column. Inline calibration minimizes the anion contamination.

Compared to the classical Epton titration, potentiometrically indicated two-phase titrations using organic-solvent-resistant Surfactrodes can be easily automated and require no toxic and environmentally hazardous chloroform. Even challenging matrices such as fats and oils in bath oils and hair conditioners or strong oxidizing agents in washing powder and industrial cleaners do not interfere with the titration of the ionic surfactants. Results obtained show excellent agreement to those of the Epton titration. Irrespective of the matrix, relative standard deviations of threefold determinations are all below 2.1%. While the Surfactrode Resistant is mainly used for oil-containing formulations, the Surfactrode Refill is ideal for washing powders and soaps. Both electrodes excel by their ruggedness and allow the rapid and precise determination of anionic and cationic surfactants.

Determination of nitrite, nitrate, sulfite, and sulfate in wastewater containing high levels of chloride using anion chromatography with conductivity detection after chemical suppression and after inline chloride removal.

Determination of chloride, nitrate, and sulfate in 85% H3PO4 using two-dimensional anion chromatography with conductivity detection after sequential suppression.

Determination of fluoride, acetate, formate, chloride, nitrite, nitrate, phosphate, and sulfate in wastewater containing N-methylpyrrolidone using anion chromatography with conductivity detection after chemical suppression and inline matrix elimination.

Determination of bromide, sulfate, and iodide in 1 g/L sodium chloride using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, acetate, formate, nitrate, and sulfate in a gasoline/bioethanol mixture (85% gasoline, 15% ethanol) using anion chromatography with conductivity detection after sequential suppression and Metrohm Inline Matrix Elimination.

Determination of chloride, nitrite, nitrate, and sulfate in an ambient aerosol (PM2.5) using aerosol sampling with the PILS (Particle Into Liquid Sampler) and anion chromatography with conductivity detection after sequential suppression.

Determination of trace levels of chloride, nitrate, phosphate, and sulfate in boiler feed water using anion chromatography with conductivity detection after chemical suppression.

Determination of iodide, thiosulfate, and thiocyanate in the presence of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate using anion chromatography with a high-pressure gradient and conductivity detection after chemical suppression.

This poster presents an approach that couples a Particle-Into-Liquid-Sampler (PILS) to a dual-channel ion chromatograph (IC) for measurement of aerosol anions and cations and a voltammetric measuring stand (VA) to determine the heavy metals. Feasibility of the PILS-IC-VA online system was demonstrated by collecting aerosol samples in Herisau Switzerland, at defined time intervals; air pollution events were simulated by burning lead- and cadmium-coated sparklers.

The Eco IC is an entry-level instrument that is particularly suitable for routine operations and water analysis. It is equipped with a conductivity detector and can be used both with and without chemical suppression. This Application Note describes the determination of anion content with the Metrosep A Supp 17 - 250/4.0 column. This column model is particularly suitable for water analysis at room temperature.

Determination of fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate, and iodide in a mineral water using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrate, phosphate, and sulfate in a protein formulation using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

Determination of fluoride, hypophosphite, chlorite, bromate, chloride, nitrite, bromide, chlorate, nitrate, phosphite, phosphate, sulfate, and iodide using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrite, nitrate, phosphate, and sulfate in cutting oil emulsion using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

Determination of fluoride, formate, acetate, chloride, nitrite, bromide, nitrate, sulfate, oxalate, and molybdate using anion chromatography with conductivity detection after chemical suppression and Metrohm Inline Dialysis.

Determination of fluoride, chloride, nitrate, phosphate, and sulfate in wastewater using anion chromatography with conductivity detection after chemical suppression.

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

Determination of chloride, nitrite, nitrate, phosphate, and sulfate in a strongly alkaline solution using anion chromatography with conductivity detection after chemical suppression.

Determination of chlorite, bromate, chlorate, glycolate, acetate and formate in the presence of fluoride, chloride, nitrite, bromide, nitrate, phosphate and sulfate using anion chromatography and subsequent conductivity detection following chemical suppression.

Determination of fluoride, acetate, formate, chloride, sulfate, malonate, succinate, and oxalate in Bayer liquor using anion chromatography with conductivity detection after sequential suppression.

Long-term determination of standard anions with automatic inline eluent preparation applying Dosino and Level Control technology using anion chromatography with conductivity detection after sequential suppression.

Determination of sulfite, oxalate, thiosulfate, and thiocyanate in the presence of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

This Bulletin describes the determination by ion chromatography of anions, particularly fluoride, chloride, nitrite, bromide, nitrate, and sulfate using the Hamilton PRPX100 IC anion column without chemical suppression.

Determination of chloride, nitrate, bromide, and sulfate in process wastewater using anion chromatography with conductivity detection after chemical suppression.

Determination of traces of fluoride, chloride, bromide, nitrate, and sulfate in a boiler feed water containing 10 mg/L ammonia using anion chromatography with conductivity detection after chemical suppression and inline sample preparation by cation exchange.

Determination of bromide, nitrate, and phosphate in wastewater using anion chromatography with conductivity detection after chemical suppression and dialysis for sample preparation.

A setup that allows online sampling is crucial for immediate and contamination-free analysis of power plant water samples. This application recommends a setup that facilitates simultaneous anion/cation determinations. Automated inline sample preparation combines variable preconcentration (MiPCT) and calibration with a single multi-ion standard. AN-Q-004 displays the respective cation results.

Determination of traces of fluoride, chloride, nitrate, phosphate, and sulfate in 15% NaOH using anion chromatography with conductivity detection after chemical suppression and inline sample neutralization.

Determination of chloride, nitrite, nitrate, phosphate, and sulfate in an electroplating bath after inline elimination of heavy metals by cation exchange on the 793 IC Sample Prep Module using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrite, bromide, nitrate, phosphate, and sulfate in Schoeniger absorption solution using anion chromatography with conductivity detection after chemical suppression.

The poster presents the ion chromatographic determination of organic degradation products such as glycolate, formate and acetate besides the standard anions fluoride, chloride, nitrate and sulfate.

Determination of fluoride, hypophosphite, chlorite, bromate, chloride, nitrite, bromide, chlorate, nitrate, phosphite, phosphate, sulfate, arsenate, iodide, chromate, and perchlorate using anion chromatography with conductivity detection after gradient elution and chemical suppression.

Determination of fluoride, chloride, nitrate, phosphate, and sulfate on a short column or the ions mentioned plus bromate and nitrite on a long column in water samples applying intelligent column-switching using anion chromatography with conductivity detection after sequential suppression.

Determination of traces of fluoride, acetate, formate, chloride, and sulfate in an ion exchanger eluate containing 2 g/L nitrate using anion chromatography with a step gradient and conductivity detection after chemical suppression.

FDG gypsum originates from flue gas desulfurization systems in power plants. VGB-M 701 E (2008) describes aqueous extraction methods for determining chloride in FDG gypsum using ion chromatography. The sample preparation described in the VGB permits the determination of other anions besides chloride.

Determination of chloride, phosphate, sulfite, bromide, nitrate, and sulfate in a beer using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, bromide, nitrate, sulfite, sulfate, oxalate, and thiosulfate in a process water of the paper industry using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, acetate, formate, chloride, nitrite, nitrate, phosphate and sulfate in an E85 mixture (85% ethanol and 15% gasoline) by means of anion chromatography with conductivity detection and sequential suppression. The Inline Matrix Elimination serves as sample preparation.

Partial loop injection is a well known way of sample introduction to HPLC. In ion chromatography it is not yet used to a large extent. Liquid handling with Metrohm's Dosino technology now enables to use partial loop injection on a highly reproducible and accurate level. It includes multi-level calibration out of one standard solution. This AN shows its use for parallel anion and cation determination in tap water applying one single Sample Processor. The cation results are shown in Applicatin Note C-133.

Determination of fluoride, glycolate, acetate, formate, chloride, nitrite, nitrate, and sulfate in the primary cycle water of a pressurized water reactor (PWR) using anion chromatography with conductivity detection after chemical suppression calibrated with Metrohm Inline Calibration.

Parallel anion and cation analysis is typically used when both anions and cation have to be analyzed. Here, the anion part of such an analysis is shown. The sample is injected to the anion channel from the 889 IC Sample Center by its built-in injector. The whole system is controlled by Empower applying the Metrohm IC Driver 2.0. For cation analysis, see AN-C-166.

Parallel anion and cation analysis is typically used when both anions and cation have to be analyzed in a sample. Here, the cation part of such an analysis is given. The sample is injected to the cation channel by the injector of the IC instrument bypassing the injector on the 889 IC Sample Center. The whole system is controlled by Empower applying the Metrohm IC Driver 2.0. For anion analysis, see AN-S-350.

The microbore Metrosep A Supp 4 - 250/2.0 column is particularly suitable for the analysis of anions in critical samples. A waste water sample is being analyzed in the current application. The sample requires only one filtration prior to injection on the Metrosep A Supp 4 - 250/2.0. The anions are quantified with the application of conductivity detection following sequential suppression.

The study of adverse effects of air pollution requires semi-continuous, rapid and accurate measurements of inorganic species in aerosols and their gas phase components in ambient air. The most promising instruments, often referred to as steam collecting devices, are the Particle-Into-Liquid-Sampler (PILS) coupled to wet-chemical analyzers such as a cation and/or anion chromatograph (IC) and the Monitoring instrument for AeRosols and GAses (MARGA) with two integrated ICs. Both instruments comprise gas denuders, a condensation particle growth sampler as well as pump and control devices. While PILS uses two consecutive fixed denuders and a downstream growth chamber, the MARGA system is composed of a Wet Rotating Denuder (WRD) and a Steam-Jet Aerosol Collector (SJAC). Although the aerosol samplers of PILS and MARGA use different assemblies, both apply the technique of growing aerosol particles into droplets in a supersaturated water vapor environment. Previously mixed with carrier water, the collected droplets are continuously fed into sample loops or preconcentration columns for on-line IC analysis. While PILS has been designed to sample aerosols only, MARGA additionally determines water-soluble gases. Compared to the classical denuders, which remove gases from the air sample upstream of the growth chamber, MARGA collects the gaseous species in a WRD for on-line analysis. In contrast to the gases, aerosols have low diffusion speeds and thus neither dissolve in the PILS denuders nor in the WRD. Proper selection of the ion chromatographic conditions of PILS-IC allows a precise determination, within 4 to 5 minutes, of seven major inorganic species (Na+, K+, Ca2+, Mg2+, Cl-, NO3- and SO4 2-) in fine aerosol particles. With longer analysis times (10-15 minutes) even airborne low-molecular-weight organic acids, such as acetate, formate and oxalate can be analyzed. MARGA additionally facilitates the simultaneous determination of HCl, HNO3, HNO2, SO2 and NH3.PILS and MARGA provide semi-continuous, long-term stand-alone measurements (1 week) and can measure particulate pollutants in the ng/m3 range.

OpenLab CDS is the newest generation of chromatography data systems from Agilent, combining chromatography and mass spectrometry in a single software platform. The Metrohm IC Driver for OpenLab CDS integrates Metrohm IC instrumentation for full control and data acquisition. The present application describes the simultaneous analysis of anions and cations in a soft drink with a dual channel IC system. Eluent is prepared by applying Inline Eluent Production.

Determination of traces of iodide in bottled water using anion chromatography with UV/VIS detection.

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.

Determination of octylsulfonate, octylsulfate, dodecylsulfate, and oleate in a shower cream using reversed phase chromatography with conductivity detection after chemical suppression applying gradient elution.

The semiconductor industry requires high-purity or even ultrahigh-purity chemicals for the production of electronic components. The purity of the chemicals is crucial for the quality and efficient production of the parts. Here, hydrogen peroxide and ammonium hydroxide are analyzed applying traditional sample preparation methods like digestion and evaporation with subsequent reconstitution with ultrapure water. The received samples are injected applying intelligent Preconcentration Technique (MiPCT).

Boiler water analysis is an important task in power plant applications. Under the given conditions, the "Metrosep A Supp 10 - 100/4.0" column separates sulfite and sulfate without any organic modifier in the eluent. Even without any stabilizer, sulfite can be determined with a high reproducibility.

Sulfamic acid is a reasonably strong acid, used in descaling agents and for cleaning of dairy and brewing equipment. Here, a chemical solution is analyzed for sulfamate, chloride, nitrite, nitrate, and sulfate. As the solution can also contain hydramine, sufficient separation from the ions of interest is required.

Fast IC means short run times and a high sample throughput. This is attained using short columns and strong eluents. Fluoride, chloride, nitrate, phosphate, sulfate and oxalate are separated in less than eight minutes using the Metrosep A Supp 5 - 100/4.0.

Pyrophosphate is used as a stabilizer in aqueous hydrogen peroxide solution. “Reagent grade” solutions may contain pyrophosphate in the higher mg/L range, while “electronic grade” hydrogen peroxide should be free of this stabilizer. Here the determination of pyrophosphate in a high purity H2O2 solution (30%) is performed applying Inline Preconcentration with Matrix Elimination (MiPCT-ME) and a Dose-in Gradient.

N,N-dimethylglycine is an amino acid derivative found in plants and animals. The respective sodium salt is available as nutritional supplement. In this context it is expected to have athletic performance enhancer effects and acts against fatigue. It is also accepted as a poultry feed addition. The determination is performed applying a Dose-in Gradient with subsequent conductivity detection after sequential suppression. To enhance the selectivity of the separation, a combination of a Metrosep A Supp 7 - 250/4.0 and a Metrosep A Supp 16 Guard/4.0 was used.

Fast IC means a high sample throughput. This is attained with short columns, relatively high flows and strong eluents. Malate, tartrate, oxalate as well as sulfate are separated within three minutes.

OpenLab CDS is the newest generation of chromatography data systems from Agilent. The Metrohm IC Driver 1.0 for OpenLab CDS implements Metrohm ion chromatographs in OpenLab CDS for full control and data acquisition. This application shows the use of a gradient (Dose-in Gradient) as well as Dosino Regeneration in OpenLab CDS. Fluoride, chloride, nitrite, bromide, nitrate, sulfate, phosphate, and iodide in a standard solution are separated and determined.

This poster presents a straightforward ion chromatographic determination of HF, HNO3, short-chain organic acids and H2SiF6 in etching bath samples. Standard ions such as fluoride, nitrate, acetate and sulfate are determined via suppressed conductivity detection while dissolved silicate is spectrophotometrically detected in the same run after downstream post-column reaction (PCR) as molybdosilicic acid. Analytical results of several commercial HF-HNO3-H2SiF6 mixtures obtained by ion chromatography (IC) and titration showed good agreement, which confirms the applicability of the presented «dual» detection IC method for controlling the composition of acidic texturing baths.

Determination of chloride and sulfate in the presence of high nitrate concentrations. Optimization of the chromatographic separation by variation of the temperature and eluent composition.

Eluent preparation on demand (EPOD) is the convenient and flexible way of automatic eluent preparation. The 849 Level Control together with an 800 Dosino equipped with a 50 mL dosing unit are used to dilute an eluent concentrate to the final eluent concentration. The use of eluent concentrates is suitable for any type of eluent. This facilitates unattended operation of the system over several weeks (see AN C-134 for cation eluent preparation).

Metrohm Inline Preconcentration Technique with Matrix Elimination (MiPCT-ME) is a powerful tool that combines preconcentration, matrix elimination, and multilevel calibration. The latter only requires a single multi-ion standard solution. The 800 Dosino takes over all liquid handling tasks. The shown system setup allows sample analysis from 0.1 µg/L up to 1.0 mg/L.

Determination of bromide, sulfite, sulfate, and thiosulfate in a photographic developer solution using anion chromatography with conductivity detection after chemical suppression.

Determination of the anions in potable water using anion chromatography with conductivity detection after chemical suppression.

Determination of anions in a Schoeniger absorption solution of a test mixture without decomposition of the H2O2 using anion chromatography with direct conductivity detection.

Cleanliness is indispensable in electronics production. Ionic contaminations in particular lead to a drastic worsening of the quality of the printed circuit boards. The present Application Note describes the determination of cations on printed circuit board surfaces. The intelligent Partial Loop Injection Technique (MiPT) used for this purpose permits the determination of cations and anions in the same sample. The determination of the anions is described in AN-S-317.

Perchlorate in water is mainly due to anthropogenic sources such as fertilizers, fireworks, rocket fuel, etc. Trace analysis of perchlorate in water samples is a critical task. The high content of standard anions leads to large peaks that interfere with the very small perchlorate peak. In the heart-cut technique, the perchlorate fraction – widely freed of interfering anions – is re-injected onto the column thus providing a sharp peak.

Forensic institutes examine terrorist attacks and warfare agents via trace detection analysis of the used explosives and their residuals. Of particular importance is the acquisition of «chemical fingerprints» for criminal investigation departments and governmental security agencies. Institutes for public health and environmental protection analyze such compounds that can contaminate the underlying soil and infiltrate ground water.Forensic investigation with ion chromatography (IC) using suppressed conductivity detection allows a sensitive and robust determination of anionic contaminants such as chlorate, thiosulfate, thiocyanate, and perchlorate next to the common inorganic anions over a broad concentration range.

Ion chromatography trace analysis of anions in seawater is difficult, due to the high chloride concentrations. In contrast to chloride, nitrite, bromide and nitrate absorb UV radiation in the low wavelength range, thus enabling a UV detection of these three anions. This Application Note describes the separation on a column of the Metrosep Carb 2 - 100/4.0 type with a sodium chloride eluent. This minimizes the influence of the surplus chloride and enables low detection limits.

By using the 800 Dosino and the 849 Level Control as the only additional devices, Metrohm`s intelligent ion chromatography (IC) systems - the 850 Professional IC and the Compact IC family - can be easily extended to perform any unattended inline eluent preparation. Fully controlled by MagIC NetTM, the 849 Level Control monitors the eluent level while the Dosino performs all dosing and liquid handling tasks. Consecutive injections of a 250-µg/L standard over approximately 20 days revealed an excellent retention-time stability. After more than 800 consecutive injections, relative standard deviations for anions (F-, Cl-, NO2-, Br-, NO3-, PO43-, SO42-) and cations (Li+ , Na+, NH4+, K+, Ca2+, Mg2+) were smaller than 0.55 and 0.41%, respectively. In the case of a 24-hour sequence, retention-time precision for anions and cations was better than 0.09 and 0.08%, respectively. The presented inline eluent preparation system increases the retention-time reproducibility and allows the determination of anions and cations over a one-month period without manual eluent preparation.

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

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

Ion chromatography (IC) is the method of choice to determine the concentration of common ions in water. This information is crucial as drinking water must meet certain standards to guarantee health (e.g., nitrite and nitrate), as well as technical suitability (e.g., corrosiveness of chloride and sulfate). The Eco IC is an ion chromatograph suitable for economical routine water analysis. Using an A Supp 17 anion column, the analysis of major anions in drinking waters is robust and can be performed at ambient temperatures without additional temperature conditioning.

Determination of a nonionic surfactant of the alkyl propylene oxide derivative type in commercial mixtures containing anionic surfactants.

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

The combination of 850 Professional IC, 858 Professional Sample Processor, Dosino and MagIC NetTM software offers a variety of sophisticated ion chromatographic sample preparation techniques. One of these is the automated inline dilution of samples.After the first sample injection, MagIC NetTM verifies if the area of the sample peak lies within the calibration range. If the measured peak area is outside these limits, the software calculates the appropriate dilution factor, dilutes and automatically re-injects the sample. For all investigated ions (Li+, Na+, K+, Ca2+, Mg2+, F-, Cl- , NO2-, Br-, NO3-, SO42- ), automated logical dilution yielded coefficients of determination (R2) better than 0.9999. Direct-injection recoveries for cations and anions were within 98.6…99.5% and 93.4…100.4% respectively. In contrast, after logical dilution, recoveries for cations and anions were within 100.1…102.9% and 98.2…102.6% respectively. The relative standard deviations for all determinations involving diluted sample solutions were smaller than 0.91%.

Inline coupling of the 815 Robotic Soliprep with an ion chromatograph (IC) allows the straightforward determination of anions and cations in tablets. After automatic solvent addition and subsequent comminution, the homogenized tablet samples (Singulair and Bezafibrat) are filtered and subsequently transferred to the injector. The completely automated sample preparation saves both time and money, guarantees traceability of each sample preparation step and yields correct and precise results. In the range of 0.2…50 mg/L, six-point calibration curves for anions and cations yield correlation coefficients better than 0.99990 and 0.99991, respectively. While relative standard deviations (RSDs) for sub-ppm levels of nitrate, sulfate, calcium and magnesium in Singulair and Bezafibrat are smaller than 3.64%, RSD of ppm levels of chloride is better than 0.83%. The application of further inline sample preparation steps such as pulverizing, extracting, filtering or diluting facilitates numerous custom-tailored setups for ion determinations in exacting matrices such as animal feed, sediments or food.

Sulfide and cyanide are toxic anions. Their trace determination in any kind of water samples, especially in wastewater, is requied for safety reasons. However, metal traces present in the eluent can mask target anions due to complexation. The addition of a stronger complexing agent to the eluent mask these metal cations enabling interference free determaination. This application is mainly used for the analysis of cyanide and/or sulfide in water. However, it also fulfills the requirements of ASTM D2036 for the determination of total, amenable, weak acid dissociable cyanides. The determination of cyanide and sulfide require an alkaline eluent and amperometric detection. This Application Note describes a new column/eluent combination for optimized separation. The combination consists of the Metrosep A Supp 10 - 100/4.0 column and a sodium hydroxide eluent containing a trace of EDTA for transition metal complexation. This yields in better peak shape and detection limits below 0.1 μg/L.

This poster provides an overview of ion chromatographic methods combined with inline sample preparation for the determination of anions and water-extractable cations in biofuels. In addition, the determination of the oxidation stability is described.

VoltIC pro I is the perfect combination of voltammetry and ion chromatography for the fully automated analysis of anions, cations, and heavy metals (e.g., Zn, Cd, Pb, Cu): comprehensive water analysis on a single system.

Fast IC means a high sample throughput. This is attained with short columns, relatively high flows and strong eluents. Sulfite can be determined in beer alongside sulfate and other anions with the Metrosep A Supp 10 - 50/4.0.

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

The TitrIC flex II system is the perfect combination of titration, direct measurement, and ion chromatography for fully automated analysis of all key parameters. These include pH, conductivity, hardness, anions, cations, as well as the calculation of the ion balance: comprehensive water analysis from one system.

Determination of silicate and hexafluorosilicate (calculated) using anion chromatography with conductivity detection after chemical suppression (see AN S-277) and subsequent UV/VIS detection with post-column reaction. Hexafluorosilicate is hydrolyzed into fluoride and silicate. Both anion concentrations may be used for the calculation of the SiF62- concentration.

Azide may be formed during the production of certain pharmaceutical products. It can cause explosions during manufacturing. Therefore, its concentration in the air needs to be monitored in order to prevent such accidents. Azide (N3-) is well separated from standard anions on the Metrosep A Supp 5 - 250/4.0 under standard conditions.

VoltIC Professional 1 is the perfect combination of voltammetry and ion chromatography for the fully automated, simultaneous analysis of anions, cations, and heavy metals (e.g., Zn, Cd, Pb, Cu). The multiple-parameter analysis uses the same "Liquid Handling" elements and a shared sample changer, thus saving on space and costs.

Seawater analysis with conductivity detection is difficult due to the high excess of chloride. Especially analyzing for nitrite and bromide, UV/VIS detection is preferred as chloride is not interfering with nitrite at 218 nm. This AN shows the determination of all three UV-absorbing anions in an artificial seawater.

A setup that allows online sampling is crucial for immediate and contamination-free analysis of power plant water samples. This application recommends a setup that facilitates simultaneous anion/cation determinations. Automated inline sample preparation combines variable preconcentration (MiPCT) and calibration with a single multi-ion standard. AN-Q-005 shows the respective anion results.

The determination of disinfection byproducts is essential for drinking water manufacturers. This Application Note shows the determination of chlorite and bromate in addition to the standard anions. In order to reduce eluent consumption, separation takes place on a Metrosep A Supp 5 - 250/2.0 Microbore column, followed by conductivity detection after sequential suppression.

This Application Bulletin describes a polarographic method for the determination of cyanide that allows to determine free cyanide fast and accurately. The determination also succeeds in solutions containing sulfides, where other methods fail. Cyanide concentrations in the range b(CN–) = 0.01...10 mg/L cause no problems. Interference caused by anions and complexed cyanides has been investigated.

High-Performance Liquid Chromatography (HPLC) and Ion Chromatography (IC) are commonly used in the pharma, food, and environmental sectors to analyze samples for specific components and to verify compliance with norms and standards. However, users of HPLC may run into the limitations of this technique, e.g., when analyzing standard anions or certain pharmaceutical impurities. This white paper outlines how such challenges can be overcome with IC.

Determination of arsenic in dust from a waste incineration plant is performed. This is required as the environmental risk depends on the degree of oxidation of the arsenic species. Due to the different pKa of the respective anions, selenite requires non-suppressed conductivity detection, while arsenate is best determined with suppression. The determination of both species is achieved by switching the suppressor in and out, respectively.

Speciation analysis is an important tool in analytical chemistry giving information about the quantitative distribution of different oxidation states of one and the same metal ion. The speciation of iron(II) and iron(III) (Fe 2+/Fe 3+) is achieved by ion chromatographic separation of their anionic dipicolinic acid complexes. Afterwards, post-column reaction with 4-(2-)pyridylazo-resorcinol (PAR) allows VIS detection at 510 nm.

The determination of low nitrite concentrations in the presence of excess sodium chloride is demanding due to the small retention time difference of these two anions. Dual detection – conductivity and UV/VIS – is a powerful method for determining nitrite traces in a 20 g/L sodium matrix. The UV/VIS chromatogram displays no chloride interferences. The determination of ammonium traces in the presence of excess sodium is described in AN-C-145.

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

A combination of the 850 Professional IC and the 872 Extension Module Liquid Handling opens the field of Metrohm’s online monitoring by IC. In this application, Inline Preconcentration is coupled to Matrix Elimination (MiPCT-ME). By removing excess matrix components, corrosive anions can be sensitively determined. Additionally, this technique allows automated calibration using a single multi-ion standard solution. Online trace analysis for chloride and sulfate is possible for several different sample lines.

Chrome plating is an important electroplating technique that covers metal or plastic surfaces with a thin layer of chromium for both protection and decoration purposes. The sulfate and sulfuric acid concentrations in the baths are important parameters in the coating process and require continuous monitoring. The anions in the chrome baths are separated on the Metrosep A Supp 5 - 250/4.0 column and are determined using conductivity detection in accordance with sequential suppression.

The determination of transition metals by ion chromatography is possible with direct conductivity detection (see AN-C-137) as well as with UV/VIS detection after post-column reaction. Here, the cations are separated as anionic complexes and analyzed after post-column reaction with PAR with subsequent UV/VIS detection. Speciation determination of iron (separation of Fe(II) and Fe(III)) is possible with this procedure. For trace analysis, Metrohm Inline Preconcentration Technique (MiPCT) is applied.