Application Finder

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 lithium, sodium, ammonium, zinc, potassium, magnesium, and calcium impurities in syringe filters 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.

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.

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 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.

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

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.

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.

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

Determination of cationic surfactants in hair conditioner by potentiometric titration with dioctyl sodium sulfosuccinate using the «Ionic Surfactant electrode.

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.

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.

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

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.

Long-term determination of standard cations with automatic inline eluent preparation using Dosino and Level Control instruments and 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.

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.

Determination of the cationic surfactant «cetrimide» in an antiseptic disinfectant by potentiometric titration with sodium dodecyl sulfate using the «Ionic Surfactant» electrode.

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.

The analytical challenge treated by the present work consists in detecting sub-ppb concentrations of low-molecular-weight amines in the presence of strongly retained cationic drugs by using ion chromatography (IC) with upstream inline coupled-column matrix elimination (CCME). In contrast to direct-injection IC, where the late elution of strongly retained drugs requires eluents with added acetonitrile, the CCME technique uses two preconcentration columns in series. In an «inverse matrix elimination step, cationic drug and target amines are trapped on a high-capacity and a very-high-capacity preconcentration column, respectively. During amine determination, a rinsing solution flushes the drug to waste. This significantly shortens the analysis time and improves sensitivity as well as selectivity. Besides the determination of monomethylamine in Nebivolol hydrochloride discussed here, the CCME technique is a promising tool for detecting further low-molecular-weight amines in a wide range of drugs.

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.

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

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.

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).

In power plants, corrosion is the primary factor leading to costly and critical downtimes. In a nuclear power plant, a separate water circuit known as the Pressurized Water Reactor (PWR) ensures radioactive material stays contained while still transferring heat and energy to the other circuits. Boric acid and lithium hydroxide are added specially to the PWR circuit in amounts which can complicate other analytical measurements. Lithium prevents corrosion and must be monitored, along with other cations such as zinc, nickel, and ammonium. In order to measure these cations online at sub-µg/L range in a single analysis, the 2060 IC Process Analyzer is offered with combined Inline Preconcentration and Inline Matrix Elimination. Several cations can be analyzed in a single injection, with automated sample preparation making precise and reliable measurements easier.

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

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.

Determination of cationic surfactants in a household cleaner by potentiometric two-phase titration with sodium dodecylsulfate using the «Surfactrode Resistant» electrode.

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

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

This white paper presents IC-MS as powerful analysis technique. This multiparameter method determines various analytes such as inorganic cations and amines in one run.

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

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

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.

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 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.

N-methyldiethanolamine and piperazine are used in scrubber solutions, e.g., in the natural gas process. Testing this type of samples by ion chromatography requires a good resolution and the separation of amines from standard cations. The separation is achieved on a Metrosep C 4 - 150/4.0 column applying direct conductivity detection.

This Application Note describes the determination of N,N-diethylhydroxylamine (DEHA), triisopropanolamine (TIPA) and a cationic color developing component (CDC) in a developer solution. The analysis is performed on a high-capacity column such as Metrosep C - 250/4.0 with subsequent direct conductivity detection. To reduce the residence time of the strongly retained color developer components, the column flow rate is increased after the elution of the amines.

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.

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 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 zinc, sodium, potassium, magnesium, and calcium in an infusion solution 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.

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.

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

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.

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.

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.

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

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.

Determination of lysine as well as sodium, ammonium, potassium, and calcium in bulk lysine using cation chromatography with direct conductivity detection.

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.

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

Determination of 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).

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.

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

Determination of sodium, potassium, calcium, and magnesium in the water soluble fraction of a washing powder using cation chromatography with direct conductivity detection.

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

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

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

The concentrations of toxic, biogenic amines in foods, particularly in fish and wine, are an important quality characteristic. The present Application Note shows the separation of putrescine, cadaverine and histamine in addition to the standard cations. Separation takes place on a Metrosep C Supp 1 - 250/4.0 with Dose-in Gradient; quantification via conductivity detection following sequential suppression.

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.

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

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

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 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.

Hydrogen peroxide is available in different purity grades depending on its use. High purity H2O2 (electronic grade) requires very low contamination levels, e.g., less than 1 μg/L of trimethylamine (TMA). This application describes the determination of trimethylamine in a high-purity H2O2 solution (30%). Analysis is performed using Inline Preconcentration with Matrix Elimination (MiPCT-ME) applying conductivity detection after sequential cation suppression.

Drinking water analysis is strongly regulated by standards. In this Application Note, the cation determination according to ISO 14911 is shown. The Metrosep C 4 - 150/4.0 is the optimum separation column for this purpose.

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.

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.

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.

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

Partial loop injection is a well known way of sample introduction to HPLC. In ion chromatography, it is not yet used to a large extent. Liquid handling with Metrohm's Dosino technology now enables to use partial loop injection on a highly reproducible and accurate level. It includes multi-level calibration out of one standard solution. This Application Note shows its use for parallel anion and cation determination in tap water applying one single Sample Processor. The anion results are shown in Application Note S–287.

With the advent of electric automobiles, the demand for lithium batteries and with it the demand for lithium material will increase sharply. Brine lakes and hard silicate minerals are numbered among the most important sources of lithium. This Application Note addresses cation determination in seepage water from lithium minerals. Alkali and earth alkali metals are separated in the lithium digestions on the Metrosep C Supp 1 - 250/4.0 column, with subsequent conductivity detection after sequential suppression.

The high-capacity Metrosep C 6 - 150/4.0 cation column convinces with outstanding separations, narrow peaks, and a multitude of available eluents. In this Note, the selectivity for alkali, earth alkali, and certain transition metals, in addition to methyl and ethanol amines, is shown using a nitric acid eluent and direct conductivity detection.

Determination of traces of chloride in a quaternary ammonium hydroxide using anion chromatography with conductivity detection after chemical suppression and inline cation exchange to remove the matrix cations.

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.

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

The column temperature influences the duration of the cation separation on the high-performance Metrosep C 6 - 150/4.0 column. The retention times of lithium, sodium, ammonium, magnesium, and calcium remain practically constant with increasing column temperature, whereas those of potassium, strontium, and barium are considerably shortened. This means that the temperature can be used to reduce analysis time considerably on the Metrosep C 6 - 150/4.0.

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.

Determination of melamine in milk, diary products, eggs, and egg-based foodstuffs using cation chromatography.

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

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.

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

Bicine (2-(Bis(2-hydroxyethyl)amino)acetic acid) is a corrosive component. It has to be avoided in acidic gas sweetening solvents. These solvents are based on organic amines. Bicine is amphoteric, holding a carboxylic and an amine group. Under the applied conditions, the amine groups are at least partially protonated and therefore may be separated by cation chromatography. The detection mode is direct conductivity detection.

Sequential suppression in cation chromatography significantly improves detection limits. The determination of the blank value of the sample vial being used is thus essential for being able to achieve such low detection limits. The leaching tests of various sample vials proceed with the intelligent Preconcentration Technique with Matrix Elimination on the Metrosep C Supp 1 - 250/4.0 column with conductivity detection following sequential suppression. The 50 mL Corning® Cell Culture Flasks from Sigma-Aldrich (CLS430168) exhibit the lowest blank values.

The exploration and processing of lithium ores is gaining importance with the growing demand for lithium hydroxide. Lithium hydroxide is a key component in the manufacturing of rechargeable batteries for use in various applications including electric vehicles, home storage systems, power tools and consumer electronics. To ensure the efficiency for advanced processing of high purity lithium hydroxide, a fast and reliable quantitative detection technique is required. This application has been developed to monitor the lithium, sodium, and calcium content in the lithium processing samples and mineral concentrates.

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.

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

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.

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.

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 presented IC system with inline sample preparation allows the determination of traces of lithium and sodium (ppt) in the presence of ppm quantities of ammonium and ethanolamine.

Special brighteners are used in electroplating baths in order to provide the refined surfaces with greater brightness. The concentration of brighteners must be kept constant at all times in order to ensure uniform end product quality. This Application Note describes how brighteners are determined in parallel with IC and CVS. The corresponding CVS application can be found under AN-V-183.

Methylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) in methylpyrrolidone using Metrohm Inline Matrix Elimination.

Chipped wood and sawdust may be used in production of feed e.g., for ruminants. Melamine, a raw material for resins in wood adhesives, is limited to be used in feed. Therefore, the melamine concentration in sawdust has to be analyzed. Melamine determined after ion chromatographic separation with UV/VIS detection.

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

Ammonium determination after sequential suppression frequently exhibits non-linear calibration curves. The reason for this is the ammonium hydroxide that arises and that is present in a form characterized by low dissociation. The sequential cation suppression forms the more highly dissociated ammonium hydrogen carbonate. Ammonium and the other standard cations exhibit linear calibration curves (R > 0.9997).

This Application Bulletin describes methods for checking the condition of electrodes for surfactant titration. For testing electrodes used for ionic surfactant titration (Ionic Surfactant electrodes), sodium dodecyl sulfate (SDS) is determined using TEGO®trant. Conversely, for testing electrodes used for cationic surfactant titration (Cationic Surfactant electrodes), TEGO®trant is titrated with SDS.For non-ionic surfactant electrodes (NIO surfactant electrode), PEG 1000 is titrated with sodium tetraphenylborate (STPB).For testing Surfactrode Resistant and Surfactrode Refill electrodes, titrations of SDS with TEGO®trant are performed. Suitable criteria for the test are the height of the potential jump and the shape of the titration curve.Key word: NaPh4B

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 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.

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

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.

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 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 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 betaine in the presence of standard cations in an Echinacea product using cation chromatography with direct conductivity detection.

This poster describes a simple and sensitive method for the determination of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in water samples by suppressed conductivity detection. Separation was achieved by isocratic elution on a reversed-phase column thermostated at 35 °C using an aqueous mobile phase containing boric acid and acetonitrile. The PFOA and PFOS content in the water matrix was quantified by direct injection applying a 1000 μL loop. For the concentration range of 2 to 50 μg/mL and 10 to 250 μg/mL, the linear calibration curve for PFOA and PFOS yielded correlation coefficients (R) of 0.99990 and 0.9991, respectively. The relative standard deviations were smaller than 5.8%.The presence of high concentrations of mono and divalent anions such as chloride and sulfate has no significant influence on the determination of the perfluorinated alkyl substances (PFAS). In contrast, the presence of divalent cations, such as calcium and magnesium, which are normally present in water matrices, impairs PFOS recovery. This drawback was overcome by applying Metrohm`s Inline Cation Removal. While the interfering divalent cations are exchanged for non-interfering sodium cations, PFOA and PFOS are directly transferred to the sample loop. After inline cation removal, PFAS recovery in water samples containing 350 mg/mL of Ca2+ and Mg2+ improved from 90…115% to 93…107%.While PFAS determination of low salt-containing water samples is best performed by straightforward direct-injection IC, water rich in alkaline-earth metals are best analyzed using Metrohm`s Inline Cation Removal.

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

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.

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

Determination of trace levels of cations and amines in hydrogen peroxide is important in quality determination of high-grade semiconductor chemicals. In particular, some manufactures look for 1 ppb trimethylamine or less in hydrogen peroxide samples. Ion chromatography after MiPCT-ME* with conductivity detection after sequential cation suppression is applied.

Bethanechol is a pharmaceutical compound which is used to treat urinary retention. This API (active pharmaceutical ingredient) can be determined by cation chromatography with direct conductivity detection. A good separation is achieved between bethanechol and its degradation product 2-hydroxy-propyl-trimethyl ammonium (HPTA) and the standard cations. Peak shape and resolution meet the USP requirements for bethanechol.

2-amino-N-(2,2,2-trifluoroethyl)-acetamide is a organic building block for synthesis of pharmaceutical products. Its purity is crucial for the success of the respective synthesis step. 2,2,2-trifluoroethylamine, glycine, and inorganic cations are of interest. Their total peak area is required to be < 2 % of the peak area of all peaks above the reporting level. Separation and quantification is achieved on a Metrosep C 4 - 250/4.0 cation column.

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).

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.

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

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

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.

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

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.

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

Choline is important for the biosynthesis of numerous molecules, e.g., the neurotransmitter acetylcholine, and exists as an intermediate product in the human metabolism. Concentration determination takes place after microwave digestion. Separation is performed on the Metrosep C Supp 1 - 250/4.0 column following sequential suppression. Separation from the standard cations is outstanding.

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

Lithium is a soft alkali metal that is typically obtained from salt lake brines. Lithium is used for many applications, but especially for production of lithium-ion batteries in electric cars, mobile phones, and more. This Process Application Note presents a method to monitor lithium as well as other cations in brines by online process ion chromatography (IC), a multiparameter analytical technique that can measure ionic analytes in a wide range of concentrations.

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.

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

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.

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

According to the described method, NTA and EDTA can be determined in mass concentrations of 0.05 mg/L up to 25 mg/L in polluted water and wastewater.At first NTA and EDTA are converted to the corresponding Bi complexes by addition of Bi3+ ions at a pH value of 2.0. As these Bi complexes have significantly different peak potentials, they can be determined simultaneously by DP polarography. The interfering anions nitrite, sulfite, and sulfide are removed from the sample by acidification and purging. Interfering cations are removed by cation exchange; any NTA or EDTA heavy metal complexes present in the sample are disintegrated during this procedure. To remove surfactants and other organic components interfering with the analysis, the sample solution is run through a column filled with non-polar adsorber resin.

In natural gas production, the removal of contaminants, and in particular acidic gases such as H2S and CO2, is exceptionally important. These acidic gases are removed in the amine wash through chemical treatment with amines or alkanol amines. This application shows a convenient and precise analysis with the separation of various amines and standard cations on a column of the Metrosep C 6 - 250/4.0 type with subsequent direct conductivity detection.

Abrasive machining of e.g., metal parts requires a cooling lubricant. Their purpose besides cooling and lubrication is to inhibit corrosion. Amines are added to the emulsion to keep the pH high. In the actual application, DCHA and MDCHA have to be analyzed besides other amine components and inorganic cations. To avoid oil contamination on the IC system, Inline Dialysis is applied. The detection is performed by direct conductivity detection.

The concentration of Se(IV) in zinc plant electrolyte is determined by cathodic stripping voltammetry (CSV) in ammonium sulfate electrolyte containing EDTA and Cu. The Cu concentration has to be adapted to the sample and the deposition time. With voltammetry only free selenium is determined, therefore it has to be taken into consideration that selenium forms sparingly soluble compounds with numerous cations (e.g. Fe2(SeO3 )3 with Ks = 2·10-31).

Sorbic acid and benzoic acid and their salts are used as food preservatives (E200, E201, E201, E203 and E210, E211, E212, E213 respectively). The content of such preservatives in flavored bottled water may easily be analyzed by ion exclusion chromatography. This method determines the concentration of the respective acid and does not allow differentiating between the counter cations. The determination of sorbic acids and benzoic acid is achieved by conductivity detection after inverse suppression.

This poster presented jointly with USP at AAPS meeting shows, that we successfully developed and validated a single IC procedure for potassium assay and identification in potassium bicarbonate and potassium chloride for effervescent oral suspension. The optimized chromatographic conditions could be used for other cationic impurities, such as magnesium, calcium, sodium, and ammonium in potassium bicarbonate and potassium chloride for effervescent oral suspension. Single chromatographic method for assay and identification simplifies the overall QA/QC workflow.

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

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

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

The analytical challenge treated by the present work consists in detecting sub-ppm quantities of bromide, sulfate, aliphatic monocarboxylic acids and several alkaline earth metals in the presence of very high concentrations of sodium and chloride. Bromide, sulfate, acetate and butyrate can be reliably determined by suppressed conductivity detection. Due to matrix effects, propionate can only be detected qualitatively. This drawback can be overcome by coupling the ion chromatograph (IC) to a mass spectrometric (MS) detector. This results in reduced matrix interferences and significantly enhanced sensitivities. The cations magnesium, barium and strontium are determined by non-suppressed conductivity detection.

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

Lanthanum (La) is a transition metal which oxidizes easily in air to lanthanum(III) oxide. This oxide, as well as salts resulting from its dissolution in acid and recrystallization, is a component of different catalysts. Here, a lanthanum(III) acetate solution prepared by dissolution of lanthanum(III) oxide in acetic acid, has to be tested for a sodium contamination. The high concentration of La3+ is complexed by the dipicolinic acid in the eluent and forms anionic complexes. These complexes are eluted in the front and therefore do not interfere with the sodium impurity as well as other cations such as ammonium and calcium.

Potassium citrate and citric acid oral solutions act as systemic alkalizers. Potassium assays, validated per USP <621> and <1225>, use IC with L76 cation-exchange columns.

Determination of diethylamine and trimethylamine using cation chromatography with MS detection.

Determination of 3-dimethylamino-1-propylamine in cocoamidopropyl betaine using cation chromatography with direct conductometric detection.

Determination of trans-4-methylcyclohexylamine in a pharmaceutical product using cation chromatography with direct conductivity detection.

Determination of sodium and potassium in toothpaste using cation chromatography with direct conductivity detection.

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

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

Determination of ammonium, magnesium, and calcium in a fertilizer using cation chromatography with directconductivity detection.

Determination of tributylamine in a pharmaceutical product (gabapentine) using cation chromatography with direct conductivity detection.

Determination of Bethanechol chloride and calcium in tablets using cation chromatography with direct conductivity detection.

Determination of strontium and barium in monoethylene glycol using cation chromatography with direct conductivity detection.

Determination of magnesium, strontium, and barium in produced water using cation chromatography with direct conductivity detection.

Determination of calcium and magnesium in a dolomite sample using cation chromatography with direct conductivity detection.

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

Determination of calcium and magnesium in high-purity sodium chloride using cation chromatography with direct conductivity detection.

Determination of traces of methylamine, dimethylamine, and trimethylamine in methylpyrrolidone using cation chromatography with direct conductivity detection.

Determination of ammonium, potassium, magnesium, and calcium in a liquid fertilizer using cation chromatography with direct conductivity detection..

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

Determination of choline in infant milk powder using cation chromatography with direct conductivity detection applying Metrohm Inline Dialysis.

Determination of sodium, ammonium, methylamine, guanidine (Gu), and aminoguanidine (Agu) in wastewater using cation chromatography with direct conductivity detection.

Determination of N-methylpyrrolidone (N-MP) in a pharmaceutical product (Cefepime Hydrochloride) using cation chromatography with direct conductivity detection.

Determination of dimethylamine in Metformin (N,N-dimethylimidodicarbonimidic diamide, anti-diabetic drug) using cation chromatography with direct conductivity detection.

Determination of aluminum in phosphoric acid using cation chromatography with UV detection after post-column reaction with catechol violet.

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

Determination of sodium, potassium, DMEA (dimethylethanolamine), calcium, choline, and magnesium in a saline solution using cation chromatography with direct conductivity detection.

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

Determination of Bethanechol Chloride and HPTA (2-hydroxy-propyl-trimethyl ammonium chloride) besides sodium and calcium using cation chromatography with direct conductivity detection.

Determination of monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) 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.

Natural liquefied petroleum gas (LPG) is a mixture of hydrocarbon gases (e.g. propane and butane), but it also contains acidic contaminants (e.g. carbon dioxide or hydrogen sulfide). These gases need to be scrubbed from the petroleum gas as they are highly corrosive. This purification step, referred to as «sweetening», is often performed by using alkaline amine solutions. Thereby the amine solution absorbs the acidic gases, while the raw LPG is neutralized. To guarantee that amine residues in the sweetened gas do not influence the gas quality, the amines in the final LPG are determined by scrubbing the gas with acetic acid as described in UOP 936-96. The recent method enables the quantification of the amines dimethylamine (DMA), diethylamine (DEA), dipropylamine (DPA), and dibutylamine (DBA) by separation from standard cations.

Determination of trimethylamine in hydrogen peroxide (31 %) using cation chromatography with direct conductivity detection after inline matrix elimination, inline preconcentration, and inline calibration.

Determination of dimethylamine (DMA), trimethylaminoxide (TMAO), trimethylamine (TMA), putrescine, cadaverine, and histamine in a fish sample 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 hypophosphite, phosphite, and phosphate in a nickel bath using anion chromatography with conductivity detection after chemical suppression and inline cation exchange.

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

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

Determination of benzylamine in a beta blocker (Nebivolol) using cation chromatography with direct conductivity detection. A step gradient for fast elution of the main component is applied.

Determination of aluminum in an acidic extract containing metals (e.g., alkali, alkaline earth, iron, chromium, molybdenum, etc.) using cation chromatography with UV detection after post-column reaction with Tiron.

Determination of citrate in mineral water drinks by potentiometric titration with copper sulfate using the Cu-ISE. Before the determination, the sample is degassed and passed through a cation-exchange resin.

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

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

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

Within the scope of the USP monograph modernization, potassium is determined in potassium bicarbonate effervescent tablets for oral suspension applying cation chromatography with direct conductivity detection. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). All acceptance criteria are fulfilled.

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

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.

Harmful industrial flue gases like H2S and CO2 cause corrosion of pipes and damage the environment. Adding the correct amount of amines in scrubber solutions, e.g. ethanolamines and methylamines, will neutralize these gases («gas sweetening»). Non-suppressed cation analysis with direct conductivity detection is a straightforward and robust technique for the quantification of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), monomethylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) via ion chromatography. Thanks to the high capacity of the Metrosep C 6 column, large volumes can be injected without compromising the peak shapes. The analytical technique can be used at laboratory scale but also for process analysis.

Within the scope of the USP monograph modernization, potassium is determined in potassium bitartrate applying cation chromatography with direct conductivity detection. The USP41 monograph for “Potassium bitartrate” does not yet mention an assay for potassium. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). The assay of potassium is performed with two commercially available products according to USP definitions. All acceptance criteria are fulfilled.

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.

Within the scope of the USP monograph modernization, potassium is determined in potassium sodium tartrate applying cation chromatography with direct conductivity detection. The USP41 monograph for “Potassium sodium tartrate” does not yet mention an assay for potassium. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). The assay of potassium is performed with two commercially available products according to USP definitions. All acceptance criteria are fulfilled.

Tris(hydroxymethyl)aminomethane (TRIS) is often used in life science applications and its purity must be monitored. This analysis is possible with ion chromatography.

The titrimetric determination of nonionic surfactants on the basis of polyoxyethylene adducts (POE adducts) is described in the Bulletin. The basis for the determination is the transfer of the nonionic surfactant into a pseudo-cation compound and its precipitation titration with sodium tetraphenylborate (Na-TPB). The NIO electrode is used for the indication of the potentiometric titration. This Bulletin describes determinations in raw products, formulations and wastewater and draws attention to special features, possibilities, limits and disruptions.