Speciation of eight arsenic compounds in human urine by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection using antimonate for internal chromatographic standardization

Erik Huusfeldt Larsen, G. Pritzl, S. H. Hansen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Four anionic and four cationic arsenic compounds in urine were separated by anion- and cation-exchange high-performance liquid chromatography and detected by inductively coupled plasma mass spectrometry (ICP-MS) at m/z 75. The species were the anions arsenite, arsenate, monomethylarsonate and dimethylarsinate and the cations arsenobetaine, trimethylarsine oxide, arsenocholine and the tetramethylarsonium ion. Hexahydroxyantimonate(III) was co-chromatographed with the arsenic anions but detected at m/z 121 and used as an internal standard for their qualitative analysis. Arsenite was prone to oxidation to arsenate in urine but was stable after at least 4-fold dilution of the urine with water. Arsenite was unstable in both urine samples and standard mixtures when diluted with the basic (pH 10.3) mobile phase used for anion chromatography. This could not be prevented by adding ascorbic acid as antioxidant. The argon chloride interference at m/z 75 was eliminated by chromatographic separation of the chloride present in the sample from the arsenic analytes. The ClO+ ion detected at m/z 51 and 53 was used to monitor the retention time of chloride in the anion-exchange system. The chloride eluted about 100 s after the last analyte peak and the intensity of ArCl+ was negligible even after injection of a 1% NaCl solution (less than 200 ions s–1). The recovery of all arsenic species in urine was close to 100%. The chromatographic peaks were evaluated by their peak heights and calibration was carried out by the method of standard additions. The calibration graphs were linear for all species (r > 0.999). The limits of detection were 3–6 ng cm–3 for the cations and 7–10 ng cm–3 for the anions in urine.
Original languageEnglish
JournalJournal of analytical atomic spectrometry
Volume8
Pages (from-to)557-563
ISSN0267-9477
DOIs
Publication statusPublished - 1993

Fingerprint Dive into the research topics of 'Speciation of eight arsenic compounds in human urine by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection using antimonate for internal chromatographic standardization'. Together they form a unique fingerprint.

Cite this