Evaluation of the three most commonly used analytical methods for determination of inorganic arsenic and its metabolites in urine.

This work compares the three most common analytical methods for determination of inorganic arsenic and its metabolites in urine: high performance liquid chromatography coupled to either inductively coupled plasma mass spectrometry or atomic fluorescence spectrometry via hydride generation (high performance liquid chromatography-hydride generation-inductively coupled plasma mass spectrometry (HPLC-HG-ICPMS) and HPLC-HG-atomic fluorescence spectrometry (AFS), respectively) and atomic absorption spectrometry coupled to HG (HG-atomic absorption spectrometry (AAS)). This was done with the focus to find alternatives to ICPMS, the investment and running costs of which are rather high. Between-laboratory comparison of HPLC-HG-ICPMS and HPLC-HG-AFS showed good agreement for inorganic arsenic, methylarsonate (MA) and dimethylarsinate (DMA) (R(2)=0.91, R(2)=0.92 and R(2)=0.90, respectively, N=86). Within-laboratory comparisons of HPLC-HG-AFS, HPLC-HG-ICPMS and HG-AAS showed good agreement for all arsenic species and the sum of inorganic arsenic and its metabolites in urine (HPLC-HG-ICPMS versus HPLC-HG-AFS: R(2)=0.95; HG-AAS versus HPLC-HG-AFS: R(2)=0.95 and HPLC-HG-ICPMS versus HG-AAS: R(2)=0.97; N=89). HPLC-HG-AFS was found to be a simple, but high quality alternative to HPLC-HG-ICPMS for the speciation and quantification of inorganic arsenic and its metabolites in urine at arsenic concentrations above 10microgL(-1). Because of its considerably lower costs compared to HPLC-HG-ICPMS, it may be a good alternative in laboratories where the high cost of ICPMS is not justified in relation to the intended use of the instrument.