Application Finder

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

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

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.

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.

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.

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.

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.

1,3,5-trioxane is a heterocyclic compound formed by trimerization of formaldehyde. Trioxane is used for the production of polyformaldehyde plastics such as poly(oxymethylene) (POM) and solid fuels. Aqueous 1,3,5-trioxane solutions frequently contain trace triethylamine that requires quantification. This is performed on the Metrosep C 3 - 250/4.0 column with subsequent direct conductivity detection.

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.

Automatic dilution reduces manual work and improves the reproducibility and accuracy of the results. So far, the Inline Dilution Technique (MIDT) has been tested in a range of max. 1:100. Using a dedicated sample needle this range is enlarged significantly. This AN shows the performance of an Inline Dilution with a factor of 1:2000 as well as a comparison of manual and inline dilution for a dilution factor of 1:1000.

Ammonia is present in tobacco – either naturally or added – and is realesed during smoking. Ammonia increases the appeal of smoking, and is therefore considered to increase the addictive potential. The determination of ammonium in tobacco is performed by acid extraction and ion chromatographic separation followed by non-suppressed 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.

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.

Before the liquefaction process of the natural gas, carbonate and hydrogen sulfide need to be removed through a scrubber solution containing piperazine and N-methyl diethanolamine (MDEA). The concentration ratio of the two components is determined by ion chromatography on a Metrosep C 4 - 150/4.0 column applying direct conductivity detection.

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.

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.

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.

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.

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.

A cardioplegic solution protects the ischemic myocardium from cell death. It is applied together with hypothermia e.g. in open heart surgery. Here the simultaneous determination of aspartic acid, glutamic acid, tris(aminomethyl)aminomethane (TRIS), sodium and potassium in such a solution is given. The two amino acids can be determined as they are partially in the triple protonated ammonium form at the eluent pH. Determination is achieved by 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.

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.

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.

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.

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.

As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium and sodium content in potassium and sodium bicarbonates and citric acid effervescent tablets for oral solution. The present IC method has been validated according to USP General Chapter <621>.

As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium content in potassium bicarbonate and potassium chloride effervescent tablets for oral solution. The Metrosep C 6 - 150/4.0 column (L76) provides the required separation of potassium and magnesium. The present IC method has been validated according to USP General Chapter <621>.

Within the scope of the USP monograph modernization, sodium 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 sodium. 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. See AN-C-182 for the respective determination of potassium. Apllying this method allows to determine sodium and potassium simultaneously according to USP.

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.

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

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.

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.

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.

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.

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.

Calcium carbonate has a wide applicability in the pharmaceutical industry as an excipient and also as an active ingredient, and in the food industry as a major dietary supplement. The U.S. Pharmacopoeia (USP) monographs for calcium and magnesium carbonates tablets as well as calcium carbonate and magnesia chewable tablets currently describe manual titration as the assay procedure for calcium and magnesium. The USP has embarked on a global initiative to modernize many of the existing monographs across all compendia. In response to this initiative, two alternative analytical methods were developed to determine the analytes calcium and magnesium. This Application Note presents ion chromatography (IC) procedures using conductivity detection that provide better accuracy and specificity and are suitable for the intended purpose. These validated IC methods (according to USP General Chapter <1225>) offer a significant improvement to the existing assays because they can simultaneously determine both analytes calcium and magnesium, saving both time and effort.

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

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

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.

The assay of calcium acetate, often used as a phosphate binder for dialysis patients, can be performed with ion chromatography (IC) as per USP <621> and <1225>.

Determination of chloride and sulfate (non-quantified) in a high-viscosity oil sample using combustion digestion and subsequent anion chromatography with conductivity detection following sequential suppression.Keyword: pyrohydrolysis

Determination of fluoride, chloride, bromide and sulfate in residual solvent using combustion digestion as sample preparation and subsequent anion chromatography with conductivity detection following sequential suppression. The analysis is significant for use in dividing waste products into non-halogenated and halogenated solvents.Keyword: pyrohydrolysis

The determination of halogens and sulfur in waste products is important. The inline combination of the Mitsubishi Combustion Module with the Metrohm IC is a suitable method for this type of samples. The recovery rates are analyzed with a certified reference material, e.g., a low-density polyethylene (LDPE).Keyword: pyrohydrolysis

Latex gloves are used in clean room environments in order to prevent contaminations. The use of gloves that release corrosive halogenides or sulfate is forbidden in nuclear power plants. The total content of halogen and sulfur is determined by means of Combustion Ion Chromatography. An eluate test is carried out to check the elutable percentage of halogens and sulfate from gloves. Sample preparation is comprised of preconcentration and matrix elimination (MiPCT-ME), as described in AN-S-304.Keyword: pyrohydrolysis

The iodine content in numerous iodized X-ray contrast media (ICM) is around 50% and is determined with great accuracy using Combustion Ion Chromatography. Large quantities of H2O2 (1,000 mg/L) are required for complete absorption of the iodine. Similarly, the concentration of the internal standard should be 50 mg/L. The water content of the X-ray contrast media is determined by means of Metrohm's Karl Fischer oven method and incorporated in the final calculation.Keyword: pyrohydrolysis

Combustion Ion Chromatography combines pro-hydrolytic sample combustion and the absorption of emerging combustion gases in an oxidizing, aqueous solution that is then channeled to an ion chromatograph for the analysis of halogenides and sulfur (as sulfate). The combustion and analysis of the certified reference materials (ZRM) makes clear the reliability of Metrohm Combustion Ion Chromatography.Keyword: pyrohydrolysis

This application describes the determination of fluoride, chloride, bromide and sulfur (as sulfate) in an ethanol standard solution with halo organic (4-halogen benzoic acids; F, Cl and Br) and sulfur organic compounds (3-(Cyclohexylamino)-1-propanesulfonic acid) by means of Metrohm Combustion Ion Chromatography with flame sensor and Inline Matrix Elimination.Keyword: pyrohydrolysis

Polyisobutene (PIB) is an important raw material for a large range of products. Quality control requires the determination of the fluorine content. This task is easily done by Metrohm Combustion IC applying flame sensor technology and Inline Matrix Elimination.Keyword: pyrohydrolysis

Cyclohexane is an important organic solvent. Recycled cyclohexane must be tested for trace substances, e.g., chloride and sulfate. Metrohm Combustion Ion Chromatography with flame sensor and Inline Matrix Elimination is the method of choice.Keyword: pyrohydrolysis