Simultaneous determination of arsenic species and chromium(VI) by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry

The simultaneous determination of As(III), As(V), monomethylarsenic acid (M MA), dimethylarsinic acid (DMA) and Cr(VI) in fresh water has been carried out by coupling an anion-exchange column to an inductively coupled plasma-m ass spectrometer. Optimisation of chromatographic conditions led to baselin e separation of signals from the five species in approximately 9 min using gradient elution. Detection limits were 0.02-0.05 mug As 1(-1) and 5.5 mug Cr 1(-1). Repeatability was 2-3% for arsenic species and higher, i.e., 8%, for Cr(VI) due to the higher background for this species. Arsenic species a nd hexavalent chromium stability in surface water samples was evaluated, an d storage conditions were set to 1 day at 4 degreesC in polyethylene flasks (without acidification) in order to avoid As(III)-As(V) conversions. The m ethod was applied to the analysis of surface water. (C) 2001 Elsevier Scien ce B.V. All rights reserved.