Simultaneous Speciation of Arsenic and Selenium Compounds by ION-Chromatography with Inductively Coupled Plasma Mass Spectrometry as Elemental Specific Detector

Abstract

The feasibility of simultaneous speciation of arsenic and selenium compounds after ion chromatographic separation was investigated using inductively coupled plasma mass spectrometry (ICP-MS) as multielement specific detector. Separation conditions were optimized. Under the optimized conditions, six arsenic species: arsenous acid [As (III)], methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenic acid [As(V)], arsenobetaine (AsB), arsenocholine (AsC), and four selenium species: selenous acid [Se(IV)], trimethylselenonium cation (TMSe⁺), selenocystine (SeCys), selenomethionine (SeMet), can be separated in the same injection within 8 minutes and determined at environmental concentration levels. The detection limits are estimated in the range of 0.04–0.6 μg/L for arsenic compounds and 0.18–0.35 μg/L for selenium compounds.