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This work was carried out with a Metrosep C 2 - 150 separation column, the following eluent parameters being investigated: nitric, tartaric, citric and oxalic acid concentration and concentration of the complexing anion of dipicolinic acid (DPA). The aim was to determine the effect of these parameters plus that of the column temperature on the retention times of alkali metals, alkaline earth metals, ammonium and amines using ion exchange chromatography with non-suppressed conductivity detection. Due to similar affinities for the ion exchange column, transition metals are difficult to separate with the classical nitric, tartaric, citric and oxalic acid eluents. Partial complexation with the dipicolinate ligand significantly shortens the retention times and improves the separation efficiency. However, too strong complexation results in a rapid passage through the column and thus in a complete loss of separation. Apart from a change in the elution order of magnesium and calcium at high DPA concentrations, other non-amine cations are only slightly affected by the eluent composition. Irrespective of the tartaric acid and nitric acid concentration in the eluent, an increase in column temperature shortens the retention times and slightly improves the peak symmetries of organic amine cations, particularly in the case of the trimethylamine cation. In contrast, an increase in column temperature in the presence of DPA concentrations exceeding 0.02 mmol/L increases the retention time of the transition metals. Depending on the separation problem, variation of the pH value, the use of a complexing agent and/or an increase in column temperature are powerful tools for broadening the scope of cation chromatography.

Comparative measurements show that the new Metrosep C 4 cation column has even better separation characteristics than the previous Metrosep C 2 and Metrosep Cation 1-2 column types. The Metrosep C 4 column has a clearly improved peak shape which leads to a better separation of the individual peaks. Using Metrosep C 4 the number of theoretical plates per meter was noticeably higher than that obtained on the Metrosep C 2 or C 1-2 column. Additionally for standard cations transition metals and amines, the Metrosep C 4 column shows better results with respect to peak shape, peak height, resolution and asymmetry factor. The clearly improved resolution of the C 4 column with its narrow and high peaks achieves baseline separation for six standard and six transition metal cations. Analysis times and peak areas obtained with the C 4 column are in the same range as those obtained with its predecessors.As a result of the latest production methods and materials, the promising Metrosep C 4 column excels by an outstanding separation performance for complex mixtures comprising standard cations, transition metal cations and amines.

The combination of 850 Professional IC, 858 Professional Sample Processor, Dosino and MagIC NetTM software offers a variety of automated ion chromatographic sample preparation and calibration techniques available as an anion, cation or dual channel system. Calibration is straightforward and requires only one multi-ion standard.Inline calibration allows the calibration of any standard concentration in the ppt range by using one single stable standard solution at the ppb level. By using a preconcentration column and switching the valves one, two or more times different calibration concentrations at the ultra-trace level can be created with unprecedented reproducibility. The inline preconcentration technique uses a pre-concentration column and is ideally suited for trace analysis in complex matrices, especially when combined with matrix elimination. Besides facilitating the preparation of g/L to ng/L calibration graphs Metrohm`s intelligent techniques are capable of logical decision making. While Metrohm`s intelligent Partial Loop technique (MiPT) allows samples with a wide concentration range to be injected without previous manual dilution, the intelligent inline dilution technique, after the first sample injection, compares peak areas, calculates, if necessary, the dilution factor, dilutes and automatically re-injects the sample. The presented inline techniques allow the rationalization of the time-consuming, error-prone and cost-intensive manual preparation of standard solutions. They guarantee that the determined sample concentrations always lie within the calibration range. Higher sample throughputs as well as lower analysis costs and improved data reliability are achieved.

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.

In routine chemical analysis, the predominant challenge involves a higher sample throughput, improved reproducibility, liquid handling flexibility and reduced personnel costs. In response to these requirements, the 872 Extension Module Liquid Handling in combination with the MagIC NetTM software and the well-proven Dosino technology expands the possibilities of inline sample preparation and opens up new fields of application. Among others, the module can be used, together with an optional mixing vessel, for pH adjustments, pre-column derivatizations, or the mixing of solutions.As a representative of an inline sample preparation technique, this poster describes the performance of precise dilutions. By using only one single stable standard solution, multi-point calibration curves can be automatically recorded by diluting a concentrated standard in an external vessel.

Available sample size, mass sensitivity, efficiency and the detector type are important criteria in the selection of separation column dimensions. Compared to conventional 4 mm i.d. columns, microbore columns excel, above all, by their low eluent consumption. Once an eluent is prepared, it can be used for a long time. Additionally, the lower flow rates of microbore columns facilitate the hyphenation to mass spectrometers due to the improved ionization efficiency in the ion source.With the same injected sample amount, a halved column diameter involves a lower eluent flow and results in an approximate four-fold sensitivity increase. In a converse conclusion, this means that with less sample amount, microbore columns achieve the same chromatographic sensitivity and resolution than normal bore columns. This makes them ideally suited for samples of limited availability.

Metrohm`s intelligent Preconcentration Technique with Matrix Elimination (MiPCT-ME) excels in its capacity to perform automatic ion chromatographic determinations over 6 orders of magnitude. Crucial requirements for this are the system`s intelligence and the exact measurement of the sample volume. While the intelligence allows to compare results and take decisions, the dosing device takes over the high-precision liquid handling of even single-digit microliter volumes to the preconcentration column. By using only one analytical setup and without additional rinsing, samples containing both ultratraces and high concentrations can be analyzed.As the other Metrohm Inline Techniques, the MiPCT-ME technique presented reduces the workload, ensures complete traceability, is free of carryover effects and significantly improves accuracy and reproducibility of the results.

The poster describes how different suppressors (MSM and MCS) work and mentions possible applications.

By combining the information from electrochemical and spectroscopic techniques, UV/VIS spectroelectrochemistry (UV/VIS-SEC) allows a comprehensive analysis of electron-transfer processes and complex redox reactions. The anodic oxidation of a N-aryl-D2-pyrazoline derivative was investigated by combining cyclic voltammetry and UV/VIS spectroscopy. In-situ measured UV/VIS absorbance depicted the absorption changes that accompanied the anodic oxidation and could therewith prove the stability of the electrogenerated radical cation. UV/VIS-SEC provides a powerful tool for the in situ study of shorter-lived species, reaction mechanims, and kinetics in a wide variety of electrochemical active organic, inorganic, and biological molecules.

This Bulletin is a supplement to Application Bulletin no. 36 (Half-wave potentials of inorganic substances) in the sense that the half-wave potentials of 100 different organic substances are listed. At the same time the supporting electrolytes used and the limits of determination are given.The various substances are listed in alphabetical order. The most important polarographically active functional groups are taken into consideration. This means that substances for related structures can also be determined polarographically in the same or similar supporting electrolytes, although they may not appear in the list.Unless otherwise stated, the half-wave potentials refer to a temperature of 20 °C, and the potentials are given in volts, measured with a sat. KCI-Ag/AgCl electrode assembly.The determination limits give the smallest concentrations which can be measured without risking serious errors in the results. In all cases, the limit of detection lies below the limit of determination.

This bulletin contains two parts. The first part gives a short theoretical overview while more details are offered in the Metrohm Monograph Conductometry. The second, practice-oriented part deals with the following subjects:Conductivity measurements in general; Determination of the cell constant; Determination of the temperature coefficient; Conductivity measurement in water samples; TDS – Total Dissolved Solids; Conductometric titrations;

Mixtures of aluminum and magnesium ions can be analyzed automatically using potentiometric titration. The excess DCTA is back-titrated with copper(II) sulfate solution after the addition of 1,2-diaminocyclohexanetetraacetic acid (DCTA) and complex formation. The ion-selective copper electrode is used here as the indicator electrode. First, the aluminum is determined in acidic solution and then the magnesium in alkali solution.

This Bulletin, using practical examples, indicates how the user can achieve optimum pH measurements. As this Bulletin is intended for actual practice, the fundamentals - which can be found in numerous books and publications - are treated only briefly.

This Bulletin provides an overview of the potentiometric titer determination of current titrants. Many publications only describe methods with color indicators. However, the titration conditions chosen for the titer determination should resemble those used for the actual analysis as closely as possible. The tables contain suitable titrimetric standard substances and electrodes for selected titrants as well as additional information. Following this, an example is given to show what an SOP for a titer determination could look like.

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 aluminum using cation chromatography, post-column reaction and UV detection.

Determination of lead, zinc, indium, cadmium, cobalt, ammonium, potassium, manganese, magnesium, and calcium using cation chromatography with direct conductivity detection.

Determination of mono-, di-, and trimethanolamine (MMA, DMA, TMA respectively), in the presence of lithium, sodium, ammonium, potassium, magnesium, cesium, calcium, and strontium using cation chromatography with direct conductivity detection.

Determination of traces of methylamine, isopropylamine diethylethanolamine, and diethylamine in the presence of lithium, sodium, ammonium, potassium, magnesium, and calcium using cation chromatography with direct conductivity detection.

Determination of traces of lutetium, ytterbium, thulium, erbium, terbium, gadolinium, samarium, neodymium, praseodymium, cerium, and lanthanum using cation chromatography with direct conductivity detection.

Determination of traces of lutetium, ytterbium, thulium, erbium, terbium, gadolinium, samarium, neodymium, praseodymium, cerium, and lanthanum using cation chromatography with gradient elution and UV/VIS detection after post-column reaction with Arsenazo III.

Determination of hydroxylamine, ethanolamine, triethanolamine, and hydrazine using cation chromatography with direct conductivity detection.

Determination of methylamine in the presence of sodium, ammonium, potassium, magnesium, and calcium using cation chromatography with direct conductivity detection.

Determination of monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) in the presence of lithium, sodium, ammonium, potassium, calcium, and magnesium using cation chromatography with direct conductivity detection.

Determination of monomethylamine (MMA), dimethyl-amine (DMA), and trimethylamine (TMA) in the presence of lithium, sodium, ammonium, potassium, cesium, calcium, and magnesium using cation chromatography with direct conductivity detection.

Determination of lithium, sodium, ammonium, potassium, manganese, calcium, magnesium, strontium, and barium using cation chromatography with direct conductivity detection.

Determination of lithium, sodium, ammonium, and monoethanolamine (MEA) using cation chromatography with direct conductivity detection and Metrohm Inline Preconcentration and Inline Calibration.

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 required eluent concentration. The use of eluent concentrates is suitable for any eluent. This facilitates unattended operation of the system over several weeks (see AN S-296 for anion eluent preparation).

Metrohm intelligent Partial Loop Technique (MiPT) is a versatile injection mode in IC. In this application, injection volumes range from 4 to 200 µL (corresponding to 0.5 - 10 mg/L) using the 250 µL loop. Here, the use of 2 and 5 mL Dosing Units are compared.

The Metrosep C 6 columns have a higher capacity than those of the Metrosep C 4. The present Application Note describes the exceptional separating efficiency for standard cations with the three Metrosep C 6 column lengths available. The outstanding sodium-ammonia separation is particularly noteworthy.

Metrohm Inline Preconcentration Technique with matrix elimination (MiPCT-ME) is a powerful method that combines preconcentration, matrix elimination, and multilevel calibration. In this Application Note, the methodology is applied to the determination of traces of sodium in addition to 2 mg/L ammonia. The Metrosep C 6 - 250/4.0 column is used for selectivity reasons.

Sample dilution is a work-intensive routine task in the analysis laboratory. An automatic two-step dilution exponentiates the dilution factor – 1:100 – thus incorporating a dilution factor of 10,000. The intelligent dilution is made possible by MagIC Net, which calculates the essential dilution steps, and by the dosing properties of the 800 Dosino and the Liquid Handling Station. The Application Note shows statistical results of a 1:10,000 dilution.

Fast IC means short run times on separation columns with a relatively high flow rate and the standard eluent. Here the standard cations are separated within eleven minutes on the Metrosep C 4 - 250/2.0. The sodium and ammonium peaks are separated from one another under these conditions.

Fast IC means short run times on separation columns with a relatively high flow rate. Separation with the Metrosep C 4 - 150/2.0 is even quicker than that in the AN-C-150 at 1.1 mL/min. Here, the standard cations are separated within five minutes. Under the selected conditions, sodium and ammonium are no longer completely separated.

Fast IC means short run times and a high sample throughput on columns with a relatively high flow rate and the standard eluent. Mono-, di- and tri-ethanolamine are separated with the Metrosep C 4 - 150/2.0 within 2.5 minutes.

Fast IC means short run times and a high sample throughput on columns with a relatively high flow rate and the standard eluent. Mono-, di- and trimethylamine are separated with the Metrosep C 4 - 150/2.0 within four minutes.

The column stability of the Metrosep C 6 - 250/4.0 was determined in long-term laboratory tests. Two injection series per day were run on each of six days in a row. Each series was comprised of nine tap water injections, three check standard injections and six tap water injections. The IC system was shut down on the seventh day of each series. As a whole, the system ran over 10 weeks and counted a total of 2,150 injections. The results show an outstanding reproducibility and verify the high column stability.

Intelligent Inline Preconcentration with Inline Matrix Elimination (MiPCT-ME) is used for trace determination of the six standard cations in addition to zinc and diethylamine. The analysis is completed within 24 minutes on the Metrosep C 4 - 250/2.0 Microbore column. The recovery rates are in excess of 95%. The detection limits calculated with the MagIC Net software are in the lower ng/L range for a preconcentration volume of 4 mL.

Potassium bitartrate for pharmaceutical use must comply with USP requirements. The actual monograph (USP 42) uses a colorimetric method for the determination of ammonium impurities. Ion chromatography allows the measurement in a single determination under the same conditions used for the potassium assay (see AN-C-181). In the course of the USP monograph modernization, this ion chromatographic approach makes this type of analysis even easier.

Microbore ion chromatography offers better sensitivity, shorter retention times, and consumes less eluent, increasing sample throughput and reducing running costs.

Cation chromatography with sequential suppression enables the determination of cations in their hydrogen carbonate form. The eluent – usually nitric acid – is converted into carbonic acid. Following its decomposition into carbon dioxide and water, the former is continuously removed by the CO2 suppressor. The reduction of baseline noise thus achieved permits the lowering of the detection limits and improves reproducibility, even at very low cation concentrations. This Note shows the reproducibilities determined for cation concentrations of 10 µg/L.

This Application Note shows the selectivity of the Metrosep C Supp 1 - 250/4.0 column for alkyl and ethanol amines in addition to standard cations under isocratic conditions. Quantification takes place using conductivity detection following sequential suppression.

The Metrosep C Supp 2 column family is polystyrene/divinylbenzene based and therefore sequential cation suppression may be applied. This AN shows the separation and detection of different amines on the 150 mm version of the column with subsequent conductivity detection after sequential cation suppression.

The short Metrosep C Supp 2 - 100/4.0 allows applying a higher eluent flow. Together with a more concentrated eluent (7.0 instead of 5.0 mmol/L nitric acid) the run time of the four cations, sodium, potassium, magnesium, and calcium can be reduced to 5 minutes. Conductivity detection after sequential suppression is applied.

The determination of heavy metal ions in a solution is one of the most successful application of electrochemistry. In this application note, anodic stripping voltammetry is used to measure the presence of two analytes, in a sample of tap water.

In order to calculate the conductivity of an electrolyte, the cell constant of the cell must be known. The combination of the Metrohm Autolab PGSTAT204 equipped with the FRA32M module in combination with the Autolab Microcell HC setup was used for the determination of the conductivity cell constants of TSC1600 temperature controlled electrochemical cell.

The kinetic and mass transfer parameters of the electro-oxidation reaction of TEMPO were measured using the TSC Surface measuring cell for the Autolab Microcell HC system. The cell allows the study of electrochemical processes in liquid electrolytes in a three electrode configuration under temperature control.

In this application note, the advantage of recording the raw time domain data for each individual frequency during an electrochemical impedance measurement is described.

Standardisation of sodium tetraphenylborate (NaTPB) solution for the determination of potassium and for nonionicsurfactants.

Standardization of 0.1 mol/L in propan-2-ol for use in applications for the determination of weakly acidic species in non-aqueous media.

Standardization of 0.1 mol/L ammonium ferrous sulfate solution for use in thermometric titration of Cr(VI) solutions.

Standardization of cetyl pyridinium chloride solutions for use as a cationic surfactant titrant in the determination ofanionic surfactants such as sodium lauryl ether sulfate.

This Application Note discusses the standardization of thiosulfate titrant for use in the determination of copper with thermometric titration.

Thermometric complexometric titration of metals is often performed with tetrasodium EDTA. This Application Note explains the standardization of tetrasodium EDTA titrant with copper.

This Application Note explains how to use magnesium to standardize tetrasodium EDTA titrant.

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

Standardization of disodium dimethylglyoximate by thermometric titration with standard Ni(II) solution.

Standardization of barium acetate titrant used in the determination of sulfate in phosphoric acid. The same procedure is applied if barium chloride is chosen as the titrant.

Standardization of sodium fluoride titrant for determination of aluminum.

Standardization of 0.1mol/L perchloric acid in glacial acetic acid by catalyzed endpoint thermometric titration.

Standardization of titrant for direct determination of sodium.

Standardization of ~1mol/L tetrasodium EDTA solutions for thermometric complexometric analysis.

Standardization of 1 mol/L tetrasodium EDTA (Na4EDTA) solutions by titration with standard magnesium solution.

Ammonia determination via NH3 ISE requires precise calibration. Details on this are provided by the present Application Note.

Karl Fischer reagents contain buffer substances (usually imidazole) since the reaction constant is dependent on the pH value. A constant pH therefore ensures the most repeatable results. In 2015, imidazole was classified by European Union the as a CMR (carcinogenic, mutagenic or toxic) substance and the statement H360D was added, stating possible harm to fertility or a fetus. Meanwhile, other reagents free of imidazole are available for purchase. This Application Note summarizes test measurements with 34433 HYDRANAL™ NEXTGEN Coulomat AG-FI.

Determination of methylarsonic acid and dimethylarsinic acid using anion chromatography with direct conductivity detection.

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

Determination of cyanide using anion chromatography with amperometric detection at the silver electrode.

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

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

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

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

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

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

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

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

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

The determination of sugar and sugar alcohols is very important for food analysis. The Dose-in Gradient system extends the gradient capability of the standard IC system. The isocratic system is expanded to form a binary gradient system with just one 800 Dosino and one T-piece.

A low-pressure gradient enables the separation of sugar acids strongly retained on the column and sugars within an appropriate analysis time. The saccharides are separated on a column of the Metrosep Carb 2 - 250/4.0 type with subsequent pulsed amperometric detection (PAD). Galactose and arabinose are not completely separated under the selected conditions.

This Application Note describes the separation of inositol, mannitol, glucose, xylose, fructose, lactose, sucrose and cellobiose on a column of the Metrosep Carb 2 - 150/4.0 type with subsequent pulsed amperometric detection (PAD).

Mono- and disaccharides, often just called sugars, are constituents in many food products. They need to be quantified for declaration reasons. A flow gradient – on a microbore Metrosep Carb 2 - 250/4.0 column – ensures the separation of the monosaccharides while the disaccharides still elute before 50 min.

The separation of lactose, lactobionic acid, sialic acid*, 6’-sialyllactose, and 3’-sialyllactose is shown as a proof of concept for the control of these components in fermentation process for a pharmaceutical product. The acceptance criterion of a minimum resolution of the peaks (< 1.3) is reached. The separation is achieved on a Metrosep Carb 2 - 250/4.0 column with subsequent pulsed amperometric detection.

This Application Note describes the Raman spectroscopy identification of sugars such as D-galactose, D-glucose, D-maltose, D-mannose, D-sorbitol, fructose, sucrose and inositol. Rapid and non-destructive determination takes place after a suitable spectrum database has been created. Measurements with the portable Raman spectrometer Mira M-1 require no sample preparation and provide immediate and unambiguous results.

Determination of chloride, sulfate, oxalate, and fumarate using anion chromatography with conductivity detection after chemical suppression.

Separation of fluoride, chloride, nitrite, bromide, nitrate, phosphate, phosphite, sulfate, and tetrafluoroborate using anion chromatography with conductivity detection after chemical suppression.

Determination of acetate, monochloroacetate, and dichloroacetate using anion chromatography with conductivity detection after chemical suppression.

Determination of gluconate, fluoride, formate, chloride, nitrate, and salicylate using anion chromatography with conductivity detection after chemical suppression.

Determination of NTA, HEDP, and ATMP using anion chromatography with conductivity detection after chemical suppression.

Determination of lactate, acetate, chloride, methylsulfate, bromide, and sulfate using anion chromatography with conductivity detection after chemical suppression.

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

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.

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.

Determination of arsenite, arsenate, selenite, selenate, chloride, and sulfate using anion chromatography with a combination of suppressed and non-suppressed conductivity detection.

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

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

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

Determination of traces of perchlorate in a sample with a high salt load 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 sulfide, sulfite, sulfate, and thiosulfate in the presence of chloride, nitrate, and phosphate using anion chromatography with combination of suppressed and nonsuppressed conductivity detection.

Determination of the cross contamination of 100 mg/L of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate to ultrapure water using anion chromatography with conductivity detection after chemical suppression and inline ultrafiltration.

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, 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, nitrate, sulfate, phosphate, and citrate using anion chromatography with conductivity detection after chemical 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.

Calibration of fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate using intelligent partial loop injection technique and anion chromatography with conductivity detection after sequential suppression. This technique allows a calibration range of 1:100 (e.g. 1 μg/L to 100 μg/L corresponding to 2 μL to 200 μL injected volume) out of 1 calibration solution. Applying the full range of partial loop injection to the samples one calibration covers a sample concentration range of 1 to 10'000.

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, 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 perchlorate and thiosulfate using anion chromatography with conductivity detection after sequential suppression.

The state-of-the-art tri-chamber suppressor technology provides a fresh suppressor chamber for each measurement. The complete regeneration of the chamber after each sample ensures highly efficient cation exchange – today, tomorrow, and even after years of continuous operation.The chromatograms as well as the statistical data demonstrate the outstanding reproducibility of the measurements with the Metrohm Suppressor Module.

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.

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.

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.

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.

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.

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.

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.

The column stability of the microbore version of the Metrosep A Supp 5 - 250/2.0 was determined in long-term laboratory tests. Two injection series each were run on six days in a row. Each series was comprised of nine tap water injections, three check standard injections and six tap water injections. The IC system was shut down on the seventh day of each series. As a whole, the IC system ran over 12 weeks and counted a total of 2,650 injections. The results show an outstanding reproducibility and verify the high column stability.

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.

The stability of the Metrosep A Supp 5 - 250/4.0 column was determined in long-term laboratory tests. Two injection series each were run on six days in a row. Each series was comprised of nine tap water injections, three check standard injections and six tap water injections. The IC system was shut down on the seventh day of each series. As a whole, the IC system ran over 10 weeks and counted a total of 2,150 injections. The results show an outstanding reproducibility and verify the high column stability.

High-pressure gradients combine the advantages of weak and concentrated eluents. Weak eluents promote the separation of the components that elute early and in close proximity to one another; in contrast to this, concentrated eluents accelerate the analysis of the components that are stronger retained at the column. The high-pressure gradient used in this application makes it possible to separate 15 organic acid anions in a single run. The blank subtraction option in the MagIC Net software simplifies the allocation of the peaks and with it the quantification.

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 STREAM (suppressor treatment reusing eluent after measurement) is applied since quite some time. The suppressor rinsing with suppressed eluent is advantageous over ultrapure water rinsing: a smaller water dip, faster MSM equilibration, and the avoidance of an additional water supply are just a few. Injecting samples containing iron in the matrix under sulfuric acid regeneration yields reduced peak areas and broader peaks for phosphate. Switching to a regenerant based on sulfuric and oxalic acid allows full regeneration of the MSM. The overlay above shows three subsequently taken chromatograms after more than 300 injections of 10 mg/L iron(II) onto one single MSM chamber. No difference in peak shape or peak area is observed.

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.

OpenLab CDS is the newest generation of the Agilent chromatography data systems platform. The Metrohm IC Driver 1.0 for OpenLab CDS enables introducing Metrohm IC instruments to this platform for full control and data acquisition. This application shows the analysis of iodide by amperometric detection, enabling detection at trace levels. The eluent is produced automatically by the 941 Eluent Production Module. In this way, amperometric detection can be executed with the same functionality and performance as with MagIC Net.

Determination of the bromine index in low-level standards by bivoltametric titration with bromide/bromate using a double Pt electrode.

Determination of calcium in aqueous solutions by photometric titration with EDTA using the 610 nm Spectrode.

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

This Application Note describes the photometric determination of sulfate in aqueous solutions using the Optrode (520 nm). Sulfate is precipitated with an excess of barium chloride solution. Excess barium is subsequently titrated with EDTA.

This Application Note describes the photometric determination of sulfate using the Optrode (610 nm). Sulfate is titrated with a lead nitrate solution; dithizone is used as indicator.

Titrants are normally bought ready to use. However, it is necessary to determine the accurate concentration of your titrant solution on a regular basis using a primary standard. To correct the mentioned variation, a so-called «titer factor» is applied. The titer can be easily and quickly assessed by using the Metrohm brand of autotitrators. Predefined calculation formulas implemented in Metrohm titrators or software, respectively, as well as the automatic storage of the titer factor, makes standardization a simple task.

In many countries, the aluminum concentration in water is limited to 0.2 mg/L. This application note shows how the analysis of aluminum in water can be done fully automatically by complexometric titration with EDTA.

This Application Note describes the fully automated complexometric determination of barium in aqueous solutions with a copper ion-selective electrode.

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

This Application Note describes the fully automated complexometric determination of zinc(II) in aqueous solutions with a copper ion-selective electrode.

This Application Note describes automatic sulfate determination using a combined ion-selective calcium electrode. Sulfate is precipitated with an excess of barium chloride solution. Excess barium is subsequently back-titrated with a standard EGTA solution.

Aluminum and magnesium ion mixtures are analyzed using back-titration at different pH values. The ion-selective copper electrode is used here as the indicator electrode. First, the aluminum is determined in acidic solution and then the magnesium in alkali solution.

Zinc and magnesium ion mixtures are analyzed using back-titration at different pH values. The ion-selective copper electrode is used here as the indicator electrode. First, the zinc is determined in acidic solution and then the magnesium in alkali solution.

Manganese in aqueous solution can be determined using back titration in alkali solution. The ion-selective copper electrode is used here as the indicator electrode.

This application note shows the use of an ion-selective copper electrode to measure the indium concentration in an aqueous solution.

Thallium in aqueous solution can be determined using back titration in a weak acidic solution. The ion-selective copper electrode is used here as the indicator electrode.

Zirconium can be analyzed quickly and easily in slightly acidic solutions with back titration. The ion-selective copper electrode is used in this Application Note to determine zirconium in aqueous solution.

Copper can be determined using photometric titration with EDTA at a wavelength of 520 nm.

This application note describes the analysis of cadmium in aqueous solution using a copper ion-selective electrode with Cu-EDTA complex used as an indicator.

This application note describes the fast, accurate determination of cobalt with a copper ion-selective electrode (Cu ISE) and Cu-EDTA complex as an indicator.

This Application Note describes the automated complexometric determination of copper with the Cu ISE.

Magnesium can be determined with the Cu ISE. A small amount of Cu-EDTA complex is used as an indicator, as the Cu ISE is not selective for magnesium itself.

Nickel can be determined with the Cu ISE. A small amount of Cu-EDTA complex is used as an indicator, as the Cu ISE is not selective for nickel itself.

Lead can be analyzed with the Cu ISE. Diammonium tartrate is added to the solution to prevent the precipitation of lead hydroxide in the alkali titration medium.

Barium acetate is used as titrant for conductometric sulfate determination. It can be standardized with desiccated sodium sulfate.

Lead is determined at pH 4 to 5 using back titration with zinc sulfate. Xylenol orange is used as an indicator for visualization of the equivalence point. The equivalence point is detected with the Optrode at a wavelength of 574 mm.

Manganese is determined as Mn(II) in aqueous solutions at pH 10 with Eriochrome Black T as indicator. Ascorbic acid is added to ensure that manganese is present in its bivalent form. The precipitation of water-insoluble manganese hydroxide is prevented by adding triethanolamine (TEA). The Optrode is used for detection at a wavelength of 610 nm.

OMNIS is the ideal system for quick and accurate determination of aluminum in aluminum chloride using complexometric back titration with an ion-selective copper electrode (Cu-ISE). Copper sulfate is used as the titrant.

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.

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

The Metrosep C 4 columns are mainly used for the separation of alkali and alkaline earth metal cations including ammonium and organic amines. Additionally transition metals may be determined.

The determination of amino acid is an important task in pharmaceutical and biochemical applications. A binary gradient separates in this example 17 amino acids of a commercially available standard solution. The post-column reaction with ninhydrin requires a temperature of 120 °C, while the samples need to be cooled for stability.

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 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.

Determination of 1-methyl-nicotinamide hydrochloride in a standard using Na2CO3 as electrolyte.

Accurate determination of Fe(II) and Fe(III) in water is crucial for many industries. Cathodic sweeping voltammetry (CSV) offers a robust, cost-effective solution.