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Ni and Co are determined in triphosphate by adsorptive stripping voltammetry (AdSV) in ammonia buffer at pH 9.5 with addition of dimethylglyoxime (DMG).

Determination of cuprous ions in the presence of ferrous ions in electrochemical copper leaching solutions.

This poster presents a highly reproducible procedure for the determination of the sodium contribution of acid-extractable organic species in Bayer process liquor. The precision of the method is estimated to be 0.2% RSD.

Determination of Fe3+ by iodometric titration. Useful if Fe3+ is accompanied by Al3+, Mg2+, Ca2+ and Fe2+.

Determination of the total sodium content of sodium aluminate liquors, such as Bayer Process liquor. This method is suitable for the analysis of all sodium aluminate solutions down to at least 1 g/L as Na2CO3. The determination may be automated by adding an 814 USB sample processor to an 859 Titrotherm.

As much as the many types of cement may differ from one another, the characteristic that all of them have in common is the presence of the elements calcium, magnesium, iron, aluminum and silicon.Calcium, magnesium, iron and aluminum can be determined using various indicators following digestion of the cement sample using photometric titration with the Optrode at 610 nm. The determination of silicon, on the other hand, is gravimetric.

Determination of nickel, zinc, cobalt, iron(II), and manganese in lithium bromide using cation chromatography with UV/VIS detection (520 nm) after post-column reaction with PAR.

This Application Note treats the photometric titration of nickel using the Optrode (520 nm). Murexide was used as the indicator and EDTA as the titrant.

In order to extract aluminum from bauxite, the aluminum ore is exposed with a caustic soda solution under pressure in the temperature range of 150 to 200 °C. Dilution and pH value setting are implemented by the addition of 170 mmol/L citric acid prior to calcium determination with ion chromatography in the Bayer caustic soda. Doing so establishes a pH value of 4.5 and prevents precipitation of aluminum hydroxide. The IC separation takes place on the Metrosep C 4 - 150/4.0 column with a citric acid eluent.

This Application Note describes the determination of aluminum ion down to approximately 0.5 g/L in acidic solutions containing ferric, ferrous, and other ions whose hydroxides do not dissolve in strongly basic solutions.

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

Cadmium, lead, and copper are determined by anodic stripping voltammetry (ASV) at the HMDE using aqueous nitric acid as supporting electrolyte.

Thiourea forms highly insoluble compounds with mercury. The resulting anodic waves are used for the polarographic determination of thiourea. For the analysis of very small quantities (µg/L), cathodic stripping voltammetry (CSV) is used. Differential Pulse measuring mode is used in both cases.

Determination of zinc, lithium, cobalt, sodium, ammonium, potassium, manganese, magnesium, and calcium in power plant feed water stabilized with 7 ppm monoethanolamine using cation chromatography with direct conductivity detection.

Determination of nickel, zinc, iron(II), and manganese in lithium bromide using cation chromatography with UV/VIS detection (520 nm) after post-column reaction.

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.

Determination of magnesium, manganese, and zinc in a zinc sulfate solution using cation chromatography with direct conductivity detection.

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

Determination of calcium and magnesium in rock extracts using cation chromatography with direct conductivity detection.

Anodic stripping voltammetry (ASV) at the HMDE is used to determine manganese in triphosphate. The sample is first digested and then measured in an alkaline solution.

Automated determination of the zirconium content of zirconium acetate, as well as other zirconium compounds which can be rendered soluble as zirconium acetate.

Germanium can be determined by adsorptive stripping voltammetry (AdSV) at the HMDE using acetate buffer as supporting electrolyte and catechol as complexing agent.

Determination of sulfate, molybdate, and chromate in a plating bath using anion chromatography with conductivity detection after chemical suppression.

Potash is commonly mined from ore, deposited after ancient inland oceans evaporated. The potassium salt is then purified in evaporation ponds. At the end of this process, the potash is typically obtained as potassium chloride. Potash is mainly used as fertilizer, providing potassium—an essential nutrient—to plants. Additionally, it is used in the chemical industry and to produce medicine. Potassium content in potash is typically determined by flame photometry (F-AES) or ICP-OES. However, these techniques have high investment and running costs. By applying the historically used gravimetric precipitation reaction as a thermometric titration, it becomes possible to rapidly and inexpensively determine the potassium content in potash within minutes.

Determination of Zn, Cd, Pb, Ni, and Co in FeCl3 solution of 40%.

Cr(VI) is determined at the HMDE in an electrolyte containing ethylenediamine and acetate. Because Cr(III) is electrochemically inactive, all Cr has to be oxidised prior to analysis.

Determination of Ni, Sb, Cd, Tl, and Cu in a neutral, highly concentrated zinc solution from the plating industry.

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.

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.

Water chemistry of the water-steam cycle is crucial for maintaining plant reliability and for ensuring optimal plant operational conditions. Impurities such as corrosion products in ionic, colloidal, or oxide forms are ubiquitous in feedwater, condensate, and reactor coolant. This application shows the determination of sub-ppb levels of Cu, Ni, Zn and standard cations (e.g., Na+, NH4+, Mg2+, Ca2+) in the water-steam cycle of a BWR.

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.

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.

Determination of zinc, sodium, calcium, and magnesium in an industrial bath containing cooling lubricants using cation chromatography with direct conductivity detection.

Cobalt can be determined in the presence of high concentrations of gold at the DME using 5-sulfosalicylic acid as supporting electrolyte and DMG as complexing agent.

The concentration of Pb in Sn soldering contacts is determined by anodic stripping voltammetry (ASV) in an electrolyte containing citrate, oxalic acid, HCl, and cetyl trimethyl ammonium bromide.

Water in steel-based cooling systems requires a pH value slightly above 7 to prevent corrosion. Often ammonium or organic amines are applied for pH adjustement. This application shows the separation of typical amines besides inorganic cations. Sample preconcentration applies combined Inline Preconcentration and Matrix Elimination (MiPCT-ME).

Determination of zinc, sodium, ammonium, and manganese in the presence of magnesium and calcium in an extract of a zinc compound using cation chromatography with direct conductivity detection.

Determination of Zn, Cd, Pb, Cu, Ni, Co, and Fe in freeze-dried hops after a wet digestion.

Determination of phosphate content in an acid etching bath.

Determination of sodium, potassium, iron(II), magnesium, and calcium in an extract of monoethylene glycol using cation chromatography with direct conductivity detection.

Determination of sodium, potassium, iron(II), magnesium and calcium in antifreeze (monoethylene glycol) using cation chromatography with direct conductivity detection. Ascorbic acid reduces iron(III) to iron(II). In this way total iron is determined as iron(II).

Simultaneous determination of Zn, Cd, Pb, Cu, Fe, Ni, and Co in 50% NaOH.

The concentration of Fe(total) is determined polarographically in a chromium electroplating bath. The method is suitable for iron in concentrations in the ppm range. Fe(II) and Fe(III) show signals with the same sensitivity.

The concentration of Tl in a cyanidic Au bath is determined by anodic stripping voltammety (ASV) without further addition of electrolyte.

Determination of zinc, sodium, potassium, magnesium, and calcium in an infusion solution using cation chromatography with direct conductivity detection.

Determination of copper, zinc, iron(II), and manganese in red wine using cation chromatography with UV/VIS detection after post-column reaction with PAR.

In pressurized water reactors (PWRs), light water is used as primary coolant. Boron (as boric acid) readily absorbs neutrons and is added to the coolant to control reactivity. Lithium hydroxide assures a pH value greater than 7 to prevent corrosion. This application allows to measure sub-ppb levels of zinc, nickel, calcium, and magnesium besides high boric acid and lithium hydroxide concentrations.

Acidic solutions used as scrubber solutions for ammonium typically have a pH of 2 or lower. This pH value is too low for silica based IC columns typically applied in direct conductivity detection of cations. The Metrosep C Supp 2 - 250/4.0 is polymer based and allows injecting low pH samples. An acidified drinking water sample spiked with ammonium is analyzed. The results indicate that such acidic solutions can be analyzed with conductivity detection after sequential cation suppression.

Determination of free acid in copper refining solutions.

Silver and nitric acid are determined in silver electrolyte solutions by means of thermometric titration. The method provides accurate results in a short time and is ideally suited for routine process control.

Determination of palladium(II) by potentiometric titration with hexadecylpyridinium chloride using the «Ionic Surfactant» electrode.

Determination of magnesium, cadmium, and iron in phosphoric acid using cation chromatography with direct conductivity detection.

Determination of chloride in Bayer process liquor.

Determination of mixtures of sulfuric, phosphoric, and nitric acids. The procedure is suitable for automated analysis using an 814 Sample Processor.

Calibration of lithium, sodium, ammonium, zinc, potassium, magnesium, and calcium using the partial loop technique and cation chromatography with direct conductivity detection. 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 e.g. 2 μL of a 10 mg/L solution corresponds to the highest calibration level (100 μg/L) while 200 μL of a 1 μg/L solution corresponds to the lowest calibration level.

Determination of nitrate, phosphate, sulfate, and chromate in a cataphoretic paint bath using anion chromatography with conductivity detection after chemical suppression.

Determination of Cr(VI) and Cr(III) in chromium baths by iodometric potentiometric titration with thiosulfate using the combined Pt electrode.

Determination of lithium, sodium, ammonium, zinc, potassium, magnesium, and calcium impurities in syringe filters using cation chromatography with direct conductivity detection.

This Bulletin describes potentiometric titration methods for checking sulfuric acid and chromic acid anodizing baths. In addition to the main components aluminum, sulfuric acid, and chromic acid, chloride, oxalic acid, and sulfate are determined.

Wastewaters often contain high loads of sodium, making the determination of minor cations quite a challenge. In the present wastewater study, the determination of lithium, ammonium, zinc, strontium, and barium is requested. If the sodium concentration exceeds 2 g/L, this negatively influences the peak shape of closely eluting peaks. Applying a appropriate dilution factor to the sample enables the quantification of minor cations. Therefore zinc and barium can be properly quantified with a dilution ratio of 1:2, while lithium and ammonium require minimum dilution factors of at least 1:10 and 1:100, respectively.

Determination of aluminum in acidic, basic, and neutral solutions; including aluminum chloride, aluminum chlorohydrate (also in anti-perspirant formulations), alum, etching solutions, and aluminate solutions.

Determination of Cr and Se in a silver plating bath.

Determination of Sn and Pb in an organo plating bath.

Cobalt is analyzed in aqueous solutions using direct titration with EDTA at a pH value of 9. The indicator is murexide. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Nickel analysis can be carried out conveniently in alkali media using photometric titration. Murexide is used as the indicator for visualization of the endpoint. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Determination of hydrofluoric acid in mixed acid etchant solutions.

Simultaneous determination of cyanide and silver in a silver plating bath by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of total basicity of extractable organic compounds of acidic character in Bayer process refinery liquors.

Determination of sulfate in hydrochloric acid digest of gypsum using anion chromatography with direct conductometric detection.

This Application Note describes the fully automated complexometric determination of total iron in cement with a copper ion-selective electrode.

Thiourea measurement during copper electrorefining can be complicated by high chloride levels. Voltammetric analysis overcomes this issue, improving copper quality.

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.

Two separate titration sequences are required to analyze the mixture:- titration of the HF content with Al(NO3)3 (the «elpasolite» reaction)- titration of the H2SO4 with BaCl2 followed by titration with NaOH to determine the «total acids» contentThe HF, H2SO4, and «total acids» contents are converted to a HNO3 equivalent, with the HNO3 content found by subtracting the HF and H2SO4 from the «total acids» content.

Determination of chloride, sulfate, chromate, methanesulfonic acid (MSA), methanedisulfonic acid (MDSA), and ethanedisulfonic acid (EDSA) in a chromium plating bath using anion chromatography with conductivity detection after chemical suppression.

Determination of Fe and Zn in a nickel sulfate bath containing surfactants after UV digestion.

The determination of cations 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-S-302 describes the corresponding anion determination.

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.

The determination of the total causticizer, sodium carbonate and aluminum oxide contents in (Bayer) process liquors can be accomplished with high precision and speed by using the 859 Titrotherm in a thermometric acid-base titration. A complete titration takes approximately 5 minutes.The procedure is an automated adaptation of the traditional Watts-Utley method, and is similar to the VanDalen-Ward thermometric titration method, but with the added advantage that the analysis can also be performed for the carbonate content of the liquor.

This Application Note describes the determination of the free and total hydroxide and aluminum oxide content in Bayer process and other aluminate liquors. The method is not subject to interference by carbonate ions. An aliquot of sodium aluminate liquor is titrated with potassium hydrogen carbonate solution to yield the free hydroxide ion content of the liquor.

Determination of chromate in cement using anion chromatography with conductivity detection after chemical suppression.

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.

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.

The concentration of Cr(VI) in cement is determined in tartrate electrolyte after acid extraction of the sample.

Determination of Cu and Cr in an etching bath. Due to the high concentrations of Mn and Ni, Cu is determined as the EDTA complex and Mn as DTPA complex.

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

This Application Bulletin describes the voltammetric determination of the elements antimony, bismuth, and copper. The limit of detection for the three elements is 0.5 ... 1 µg/L.

Determination of traces of gadolinium, samarium, neodymium, cerium, and lanthanum using cation chromatography with direct conductivity detection after Metrohm Inline Filtration.

In this Application Note, stepwise dissolution measurement (SDM) is applied to aluminum samples coated with different materials, in order to gain insights in corrosion protection. The combination of the Autolab PGSTAT204 with the 1 L Autolab corrosion cell and the NOVA software provides the suitable setup to perform SDM and other corrosion experiments.

This Application Note describes the determination of aluminum in samples containing silicon dioxide using thermometric titration and EDTA as the titrant. Excess EDTA is titrated with a Cu2+ solution of known concentration. The initial, uncomplexed Cu2+ ions react immediately with the H2O2 present in the solution, leading to a recognizable sudden increase in temperature.

Barium is analyzed in alkali media using direct titration with EDTA. Phthalein purple is used as the indicator; the equivalence point is determined with the Optrode at a wavelength of 574 nm.

Palladium is determined at a pH value of 4 to 5 using back titration with zinc sulfate. Xylenol orange is used as the indicator for visualization of the endpoint. The equivalence point is determined with the Optrode at a wavelength of 610 nm.

Thallium is titrated in slightly acidic medium as Tl(III). Xylenol orange is used as the indicator to determine the endpoint. The equivalence point is determined with the Optrode at a wavelength of 574 nm.

Cadmium can be determined in aqueous solutions using back titration with zinc sulfate. Eriochrome black T is used as the indicator for this procedure. The equivalence point is determined with the Optrode at a wavelength of 610 nm.

In this Application Note, the electrochemical properties of electrodes with a micrometer-size surface area are compared with the electrochemical properties of electrodes with millimeter-size surface area. The comparison is made through cyclic voltammetry in a Fe3+/Fe2+ (ferro/ferri) solution, and the differences in the voltammograms are explained with the different diffusion profiles at the electrode-electrolyte interface.

This Application Note outlines the determination of total acidic active surface sites in zeolites with thermometric titration.

This Application Note shows that the parameter of surface basicity of zeolites can be measured by thermometric titration.

Determination of boron in ores of the element such as borax and ulexite.

Determination of hydrofluoric and nitric acid in etching baths by potentiometric titration.a) Determination of the total acid content using the combined Sb electrode and NaOH as titrant.b) Determination of hydrofluoric acid using the F-ISE and the titrant La(NO3)3.The concentration of nitric acid is then determined by calculation.

Determination of the sum of calcium and magnesium in cement by photometric titration with EDTA using the 610 nm Spectrode.

This Application Note is based on the ASTM standard G150, developed to test the resistance of stainless steel, and otheralloys related to stainless steel, on pitting formation at elevated temperature. This is achieved by determining the potential-independent critical pitting temperature (CPT), defined as the lowest temperature at which pitting evolution occurs. The CPT experiment consists of applying a potential to the specimen while the cell temperature is raised and recording the current.

Determination of Zn, Cd, Pb, Ni, and Co in Javelle water.

An automatic titration method is described using biamperometric endpoint indication for the determination of antimony in antimony-alloyed cable lead (approx. 1% Sb). A 0.01 mol/L KBrO3 solution is used as the titrant.

Determination of fluoride and chloride in gypsum using anion chromatography and subsequent direct conductometric detection.

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

This Application Note describes the digestion of a cement sample and the photometric determination of iron in accordance with DIN EN 196-2 by means of Optrode at 610 nm. Sulfosalicylic acid is used as the indicator and EDTA as the titrant for the determination.

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

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 automated complexometric determination of copper with the Cu ISE.

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.

Mercury can be determined in alkali media using back titration with zinc sulfate. Eriochrome black T is used as the indicator for this procedure. The Optrode is used for indication at a wavelength of 502 nm.

Zirconium is titrated directly with EDTA in acidic aqueous solution (buffer, pH 1). Eriochrome cyanine R is used as the indicator for this procedure. The equivalence point is determined with the Optrode at a wavelength of 520 nm.

Results from three separate single endpoint titrations are used to calculate the results. The mixture of H2SO4, HF, and NH4F/HF contains H+ from H2SO4, HF, and NH4F/HF, SO42- from H2SO4, and F- from HF and NH4F/HF. Analysis of total H+ («total acids») by NaOH titration, F- by titrating with Al(NO3)3 («total fluoride») and SO42- by titrating with BaCl2 provides the information required to determine the composition of the mixture.

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

This Application Note describes the polarographic determination of cadmium in electroplating baths used in the production of copper indium gallium diselenide (CIGS) or copper indium diselenide thin-film solar cells (CIS). Cadmium sulfide (CdS) from the electrolyte solution is deposited as a thin film on the CIS or CIGS absorber layer via chemical bath deposition (CBD).

Electrochemical methods provide an alternative to traditional methods used to determine the rate of corrosion. For example, corrosion rates, the rates at which a specimen corrodes, can be calculated from simple electrochemical measurements like a linear sweep voltammetry (LSV).

The potassium (or ammonium) ion is precipitated with sodium tetraphenyl borate, and the excess of this reagent back-titrated against the thallous(I) ion, using biamperometric endpoint detection. Ammonium can either be titrated together in an acid solution, or driven off by previous boiling in an alkaline solution. Methods are given for determining potassium in the presence of large excesses of sodium, ammonium, calcium, and magnesium.

In this Application Note, EIS is applied on three coated aluminium samples, before and after the stepwise dissolution measurement (SDM). This technique has been reviewed in the Application Note AN-COR-08.

The water content of lime is determined according to Karl Fischer using the oven method (150 °C).

This Application Note documents the suitability of hand-held Raman spectrometers, e.g., the Mira M-1, for the identification and differentiation of salts such as carbonates, phosphates, and sulfates. The focus of the work was the rating of the influence of the cationic part and of the crystal water on the Raman spectroscopy identification of the salts.

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

Determination of Ni, Co, and Fe in a PTA solution containing HCl.

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.

Determination of Zn, Cd, Pb, Ni, and Co in hydrochloric acid (37.8%).

This Bulletin describes the fully automated determination of uranium according to the method of Davies and Gray: Uranium(VI) is reduced in concentrated phosphoric acid solution with iron(II) to form Uranium(IV). With molybdenum as a catalyst, the excess iron(II) is oxidized with nitric acid. The nitrous acid that is formed is destroyed with sulfamic acid before uranium(IV) is titrated with a potassium dichromate solution in the presence of a vanadium catalyst.

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.

This Application Note covers the photometric determination of calcium in cement using the Optrode (610 nm). After digestion of the cement sample, calcium is titrated with EDTA to the murexide endpoint.

This Application Note is devoted to the photometric determination of magnesium in cement using the Optrode (610 nm). After digestion of a sample aliquot, the magnesium content is determined using EDTA titration.

Determination of Zn, Cd, Pb, Cu, and Cr in triglyceride.

Determination of Zn, Pb, Cu, and Fe in sugar after wet digestion.

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

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

Determination of sodium, potassium, calcium, and magnesium in a drip feeding formula using cation chromatography with direct conductivity detection and dialysis as sample preparation.

Determination of traces of zinc and iron(II) in the presence of lithium, sodium, ammonium, potassium, calcium, and magnesium in boiler water using cation chromatography with direct conductivity detection.

Determination of Fe, Pb, Cd, and Cu in Co(Ac)2 solution using the MME.

This Application Note describes the polarograhic determination of copper in electroplating baths used in the production of thin-film copper indium gallium diselenide solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate.Copper analysis is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.

Determination of sodium, potassium, calcium, and magnesium in instant baby milk powder using cation chromatography with direct conductivity detection and dialysis for sample preparation.

As a rule, brine samples are diluted extremely in order to avoid overloading the column. Manual dilution is very error-prone, which is why this application relies on injection with a 0.25 µL internal loop, thus saving an additional dilution step. Sodium, potassium, magnesium and calcium in brine are determined on a Metrosep C 6 - 150/4.0 column with subsequent direct conductivity detection.

Iron ore is an important resource for steel production. Its natural content of halogens is a quality characteristic due to the corrosiveness of the respective halogenides. Combustion IC applying the sacrificial vial technology is used for the analysis of fluorine and chlorine in ore. WO3 usually is added to improve the release of SO2 and therefore sulfur recovery. In this application, it also significantly improves the recovery of fluoride.

This Application Note describes a method for the determination of causticizer, carbonate and aluminum oxide in used Bayer process liquors. The method is based on processes that were developed by Watts-Utley and VanDalen-Ward.

Determination (after digestion) of zinc, cadmium, lead, copper, nickel, and cobalt in fabrication powder of vitamin tablets.

A direct thermometric titration (TET) with 2 mol/L NaOH is used to determine the HF, NH4F, and maleic acid (C4H4O4) contents of acid cleaning solutions. Three endpoints (EPs) are obtained, which may be assigned as follows:EP1: C4H4O4 (pKa1 = 1.9), HF (pKa = 3.17)EP2: C4H4O4 (pKa2 = 6.07)EP2: NH4F (pKa = 8.2)The HF content is determined by subtracting the difference (EP2-EP1) from EP1.

Halides interfere with most determinations of mercury or silver. However, if mercury or silver is titrated with sulfide ions, extremely insoluble sulfides are formed.A simple method is described that allows the direct titration of mercury(II) or silver(I) compounds in the presence of halides. The potentiometric titration takes place under alkaline conditions using thioacetamide as the titrant after formation of the EDTA complex.Organic compounds that are insoluble in alkaline EDTA can also be titrated after a Schoeniger digestion.

Determination of sodium, potassium, magnesium, and calcium in orange juice using cation chromatography with direct conductivity detection applying automated dilution and subsequent Metrohm Inline Ultrafiltration.

Long-term determination of standard cations with automatic inline eluent preparation using Dosino and Level Control instruments and cation chromatography with direct conductivity detection.

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.

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

Potentiometric titration methods for the analysis of acid and alkaline tin plating baths are presented. The following methods are described: tin(II) / tin(IV) / total tin, free fluoroboric acid, or free sulfuric acid, chloride in acidic tin baths, free hydroxide, and carbonate in alkaline tin baths.

Determination of hypophosphite, phosphite, tartrate, tungstate, phosphate, citrate, and pyrophosphate in an electroplating bath using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

A method for the potentiometric determination of CaCO3 in cement raw meal is described, in which the accurately weighed-out sample is treated with HCl, heated to boiling and the excess HCl is then back-titrated with NaOH.

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

Determination of lithium, sodium, potassium, magnesium, and calcium in lake water using cation chromatography with direct conductivity detection.

Tobacco additives may contain cations like ammonium (see AN-C-168) as well as other cations as counter ions of organic acids. These additives include components to retain moisture and flavor of the tobacco. Ammonium is added to increase the appeal of smoking, and is therefore considered to increase the addictive potential. The determination of cations in tobacco additives is performed by ion chromatographic separation followed by non-suppressed conductivity detection.

Whey is the remaining liquid after cheese production. It is mainly used as feed. It is also used as dietary supplement as a beverage or in powder form. This application determines lactic acid as well as cations in one determination. The Metrosep C 6 - 250/4.0 column separates sodium, potassium, magnesium, and calcium by ion exchange. It also acts as an ion-exclusion column, which separates lactic acid. Both lactic acid and the cations can be determined in the same run applying direct conductivity detection. While cations typically elute as negative peaks, lactic acid elutes as an early positive peak. MagIC Net shows both in the usual positive direction.

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

Determination of Cr, Mn, and Ti in a PTA solution containing HCl.

Determination of manganese, iron, and molybdenum (after digestion) in fabrication powder of vitamin tablets.

Determination of sodium, ammonium, potassium, calcium, and magnesium in 4% boric acid using cation chromatography with direct conductivity detection.

Determination of sodium, potassium, calcium, magnesium, putrescine, cadaverine, and histamine in a wine sample using cation chromatography with direct conductivity detection.

Determination of potassium, magnesium, and calcium in biodiesel using cation chromatography with direct conductivity detection applying automated extraction and subsequent Metrohm Inline Dialysis.

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

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).

The determination of low ammonium concentrations besides excess sodium is demanding due to the small retention time difference of these two cations. This Application Note shows direct conductivity detection as an ideal means to detect ammonium in a wastewater sample containing 400 mg/L sodium. AN-S-313 shows the analysis of nitrite traces.

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.

Determination of sulfide in mining wastewater using anion chromatography with UV detection.

Determination of sodium, ammonium, potassium, calcium, and magnesium in a grapefruit soft drink using cation chromatography with direct conductivity detection after advanced dialysis for inline sample preparation.

Determination of sodium, ammonium, potassium, calcium, and magnesium in a functional fruit juice using cation chromatography with direct conductivity detection after advanced dialysis for inline sample preparation.

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.

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.

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.

Lithium hexafluorophosphate (LiPF6) is used as an electrolyte in rechargeable batteries. Its high solubility in non-polar solvents and its non-coordinating character in particular make lithium hexafluorophosphate the ideal salt for use in lithium-ion cells. This Application describes the determination of cation traces in LiPF6 with conductivity detection following sequential suppression.

Trace cation analysis in high purity water (sub-μg/L range) requires cation chromatography after sequential suppression and intelligent Preconcentration Technique (MiPCT). Trace cations in deionized water (DI) are determined and the method detection limit (MDL according to US EPA) as well as the limit of detection (LOD = 3 x S/N) is calculated. MDL and LOD are very similar in the lowest ng/L range for this setup with 6 mL preconcentration volume.

Determination of Cd, Pb, Cu, Ni, and Co in soybean oil after extraction by boiling with HCl under reflux.

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

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

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

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

NTA in a cyanidic gold bath is determined as Bi-NTA complex by polarography. For standard addition a Bi-NTA standard solution is used.

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.

Determination of trace levels of lithium, sodium, ammonium, potassium, magnesium, and calcium in boiler feed water using cation chromatography with direct conductivity detection.

Determination of sodium, ammonium, potassium, magnesium, and calcium in an ambient aerosol (PM2.5) using aerosol sampling with the PILS (Particle Into Liquid Sampler) and cation chromatography with direct conductivity detection.

Maritime pore water contains sodium in the percentage range. The analysis of ammonia in this kind of sample requires a high column capacity and an exceptionally good separation of sodium and ammonia. These requirements are completely fulfilled by a 2 µL injection to the high-capacity Metrosep C 6 - 250/4.0 column.

Cation content in snow is greatly dependent on sampling site. Samples from remote areas are expected to exhibit lower cation concentrations. This application shows the analysis of a snow sample from an open field in an agricultural zone. Separation is performed on a microbore Metrosep C 6 - 100/2.0 column with direct conductivity detection. The relatively high ammonia content can be explained by animal husbandry in the vicinity of the sampling site.

Cation content in snow is greatly dependent on sampling site. Roadside samples are likely to exhibit a high sodium content caused by the use of road salt. This application shows the analysis of a snow sample from a roadside. Separation is performed on a microbore Metrosep C 6 - 250/2.0 column with direct conductivity detection. The 250 mm column was selected due to the large difference in concentrations between sodium and ammonia. This condition enables a baseline separation of the two cations.

Isopropylamine and dicyclohexylamine are used as emulsifiers and need to be determined in emulsions along with standard cations. However, emulsions must not be injected directly into the ion chromatograph as the organic components may damage the ion exchanger stationary phase in the separation column. Inline Dialysis as sample preparation is the perfect tool for such samples. The ions of interest are separated from the organic phase by diffusion through the hydrophilic membrane, thus protecting the column. Full automation makes the analyses even easier and more efficient for the user.

Determination of traces of lithium, sodium, ammonium, potassium, calcium, and magnesium in ethanol using cation chromatography with direct conductivity detection after Metrohm Inline Matrix Elimination.

Determination of lithium, sodium, potassium, calcium, and magnesium in tap water using cation chromatography with direct conductivity detection.

Reducing the analysis time is a demanding task because it is accompanied by a parallel reduction of peak resolution. With a Microbore column 100 mm in length, standard cations in tap water can be determined in only 5 minutes. Strontium can also be determined by simply extending the run time to 6.5 min.

Biogenic amines and trimethylamine N-oxide (TMAO) are indicators for the quality of grape fermentation. The consumption of amine-rich wines often leads to headaches, which is why the amine concentrations in wine must be monitored. This Application Note describes the determination of trimethylamine N-oxide, putrescine, cadaverine and histamine, in addition to various standard cations, with the aid of the Metrosep C 6 - 100/4.0 column and subsequent direct conductivity detection.

Cation analysis in drinking water is a routine task in ion chromatography and can be achieved with a variety of separating columns. The use of a microbore Metrosep C 6 - 250/2.0 column with a high eluent concentration makes it possible to reduce analysis time to less than 12 minutes. Very symmetrical peaks with high sensitivity for the divalent cations are also achieved. Direct conductivity detection is applied.

Electrochemical impedance spectroscopy or EIS has been used effectively to measure the polarization resistance for corrosion systems and for the determination of corrosion mechanisms.

Biogenic amines are released during the winemaking process. In wine, they are present as odorless salts. However, in the mouth their flavor is partially liberated, influencing the appearance for the wine taste. Besides this, biogenic amines have been related to lack of hygiene or poor manufacturing practices. The biogenic amines are determined applying suppressed cation chromatography.

Succinylcholine is a short-term paralyzing agent used e.g., for tracheal intubation. Choline is a building block of the drug and needs to be determined as an impurity. USP applies cation chromatography with conductivity detection after suppression. Eluent composition and column type do not exactly comply with the USP method. However, the results fulfill the respective requirements. The choline concentration of the sample is out of USP specifications.

Cation analysis by IC in wastewater is a proven method. Limiting factor is often the Na/NH4 separation. High sodium concentrations may make ammonium determination impossible due to peak overlapping. The use of sequential suppression and a Dose-in gradient improve the Na/NH4 separation and enables determination of low ammonium concentrations.

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

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

The concentration of Fe(total) is determined by polarography in alkaline electrolyte containing triethanolamine (TEA) and KBrO3. All reagents typically contain Fe impurities. Therefore a subtraction of the reagent blank is recommended.

Fast and handsome IC! Outstanding peak shapes on columns with the standard flow rate and a strong eluent. When the high-capacity Metrosep C 6 - 250/4.0 is used, this usually means long retention times. A strong eluent allows however the determination of the cations in drinking water in a short run time with very symmetrical peaks.