Arsenic speciation by liquid chromatography coupled with ionspray tandem mass spectrometry

Abstract

Ionspray mass spectrometry, a well established organic analysis technique, has been coupled to high-performance liquid chromatography for speciation of organic arsenic compounds. The ionspray source and differentially pumped interface of the mass spectrometer were operated in dual modes for elemental and molecular analysis. Tandem mass spectrometry was employed to increase selectivity. Dual mode detection was applied to demonstrate the utility of the technique for analysis of nine organoarsenic standards, including four dimethylarsinylriboside derivatives (arsenosugars). Structural fragmentation patterns showing molecular dissociation through an expected common product ion were obtained for the four arsenosugars. Molecular mode detection was utilized for qualitative verification of speciation analysis by high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry of organoarsenicals in plaice and for analysis of an arsenosugar in extracts of oyster and mussel.