title: Coupled ion chromatography for the determination of chloride, phosphate and sulphate in concentrated nitric acid.
abstract: A coupled ion chromatography (IC) system was used for the determination of chloride, sulphate and phosphate in high-purity nitric acid. Such a high ionic strength matrix causes a selectivity problem in single IC systems. The first part of the system is used for a pre-separation of the analytes from the nitrate matrix. A specially designed high-capacity anion exchanger with low retention for the analytes and high retention for nitrate was developed. The eluent stream containing the analytes was transferred to the second part of the system via a heart-cut valve and a pre-concentration column. The second system utilizes a high performance anion exchanger and is used to quantify the analytes. Recoveries of the analytes are 80-100% for phosphate, and around 100% for sulphate and chloride. Detection limits for chloride, sulphate and phosphate in concentrated nitric acid (69% w/w) are 0.1, 1 and 5 mg/l, respectively.
authors.affiliation: Laboratory for Flow Analysis and Chromatography, Department of Chemistry, Warsaw University, Pasteura 1, Warsaw 02-093, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Biesaga
authors.forename: Nicole
authors.initials: N
authors.lastname: Schmidt
authors.forename: Andreas
authors.initials: A
authors.lastname: Seubert
mesh_terms: D000837:Anion Exchange Resins; D002712:Chlorides / Q000032:analysis*; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D017942:Nitric Acid / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis*; D012680:Sensitivity and Specificity; D013431:Sulfates / Q000032:analysis*; D013997:Time Factors
chemical_list: D000837:Anion Exchange Resins; D002712:Chlorides; D010710:Phosphates; D013431:Sulfates; D017942:Nitric Acid