AN148: Determination of Bethanechol by Ion Chromatography.

Instrument Type: IC

Bethanechol chloride is a quaternary ammonium compound that is structurally and pharmacologically related to acetylcholine. A method in the USP 24 NF 19 recently proposed that the gravimetric assay for bethanechol chloride be replaced with a more specific and rugged ion chromatography assay. The proposed method specifies the use of a Dionex IonPac CS14 separator column using methanesulfonic acid (MSA) eluent and suppressed conductivity detection. Here, we applied electrolytic on-line generation of MSA to optimize reproducibility, convenience, and method transfer between laboratories.

AN144: Determination of Perchlorate in High Ionic Strength Fertilizer Extracts by Ion Chromatography.

Instrument Type: IC

This application note provides a procedure for preparing aqueous leachates of fertilizers, inorganic salts, and other materials. The perchlorate anion in these extracts can be determined in 15 min by using a Thermo Scientific Dionex IonPac AS16 column, EG40-generated hydroxide eluent, a 500-μL injection, and suppressed conductivity detection. IonPac AS16 column is a high capacity, hydroxide-selective anion exchange column with ultra low hydrophobicity designed for the isocratic separation of polarizable anions including perchlorate, iodide, and thiosulfate.

AN138: Determination of Thiosulfate in Refinery and Other Wastewaters

Instrument Type: IC

Natural gas can contain hydrogen sulfide (H2S) and carbon dioxide (CO2). These gases are corrosive and must be removed before the natural gas is fed into pipelines. This is usually accomplished by treating the gas with an amine solution. Anions introduced during this process can form heat-stable salts with the amine. Thiosulfate and sulfate are two anions commonly found in these solutions. This Application Note shows that thiosulfate can be determined in refinery and other waste waters using an IonPac AS16 column, EG40-generated eluent gradients, and suppressed conductivity detection.

AN137: Determination of Trace Anions in High-Nitrate Matrices by Ion Chromatography.

Instrument Type: IC

A direct injection method has been developed to address the need to determine trace anions in samples containing high concentrations of nitrate ion using a microbore IonPac AS15 column. Conditions are optimized for sensitive determination of anions at trace levels with the EG40 Eluent Generator. This application note describes the theoretical background, setup, and analytical procedure for a method to determine chloride, sulfate, and phosphate to low-µg/L (ppb) levels in 0.7% (v/v) nitric acid and other matrices that contain high concentrations of nitrate ion.