A comparison between ICP-MS and AFS detection for arsenic speciation in environmental samples

Performances of two atomic detectors, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Atomic Fluorescence Spectrometry (AFS) have been compared for arsenic speciation in environmental samples. Instrumental couplings, based on the use of high performance liquid chromatography (HPLC), hydride generation (HG), and the two atomic detectors were used for the speciation of arsenite, arsenate, dimethylarsinic acid and monomethylarsonic acid. Optionally, arsenobetaine was also determined using on-line ultraviolet (UV) photooxidation. The detection limits ranging from 0.1 to 0.3 μg l−1 (as As) and the precision >10% RSD obtained with HPLC-(UV)-HG-AFS were comparable with those obtained with HPLC-(UV)-HG-ICP-MS. Both instrumental coupling were applied to the NRCC-TORT-1 and several environmental samples, such as seawater, freshwater, sediments, bivalves and bird eggs, taken from two areas with different degrees of pollution. No influence of the sample matrix was observed on the results using external calibration and standard additions methods, for both coupled techniques.