Determination of arsenic species by microwave-assisted extraction followed by ion-pair chromatography-ICPMS: analysis of reference materials and fish tissues

A high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) method for the determination of primary arsenic species in seafood products is described. A low-power microwave is used for efficient extraction of arsenic species from seafood products. The separation of arsenic species is accomplished on an ODS column by gradient elution at pH 9.3. Arsenobetaine (AB), arsenite (As^III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and arsenate (As^V) were separated in less than 7 min. The detection limits are in the range of 44-66 ng As L⁻¹ for all five arsenic species based on 3 (N = 6) of the blank. The analysis of two reference materials (DORM-2 dogfish muscle and TORT-2 lobster tissue) showed good agreement with the certified values for total As. In the case of AB, the experimental results agreed well with those reported for DORM-2. For the other species mentioned above, for which there was no certification in the two reference materials, the values obtained by the proposed method were compared with those reported by other authors. In addition, samples of shrimp, fish and oyster were also analyzed by the proposed method and AB was found to be the dominant species in the range of 5.5-32.2 mg As kg⁻¹ in these samples.