Speciation of inorganic and organic arsenic forms using HPLC-ICP-MS technique in aqueous matrices

The aim of the study was to develop, optimize and validate an analytical method for the simultaneous detection and quantification of As species (As (III), dimethylarsinate (DMA), monomethylarsonate (MMA) and As (V)) from various water matrices (drinking water, surface water and groundwater) using the technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The separation of the species was achieved using an Agilent G3154-65002 precolumn, 4.6 mm x 10 mm, and an Agilent G3154-65001 column, 4.6 mm x 150 mm, at ambient temperature. The mobile phase used was 1M NaH2PO4 and 0.1 mM EDTA-2Na solution at a flow rate of 1 mL/min. Linear regression lines were drawn in the range 10-50 µg/L, the coefficients of determination (R2) obtained for each species were higher than 0.99. The quantification limits (LOQ) varied in the range 1.8 µg/L As(V) to 2.0 µg/L As(III), and in the range 3.9 µg/L DMA to 4.1 µg /L MMA for all studied matrices. These limits allow the quantification of As species in drinking water samples, surface water and groundwater at the trace level.