Abstract
In Dowex 50 column chromatography, arsenate, arsenite and methylarsonate (MAA) were quantitatively recovered in the unadsorbed fraction, dimethylarsinate (DMA) and arsenobetaine (AB) in the NH4OH fraction and arsenocholine (AC) in the HCI fraction. These arsenic compounds were subjected to HPLC using ion-exchangers and specifically monitored with an inductively coupled argon plasma emission spectrometer (ICP). Mutual separation of arsenate, arsenite, MAA and DMA was achieved on Nucleosil 10SB (anion exchanger) with 0.02M phosphate buffer (pH 7.0) and that of DMA, AB and AC on Nucleosil 10SA (cation exchanger) with 0.1M pyridineformate buffer (pH 3.1). A linear relationship between the peak height and the arsenic amount was obtained for each arsenic compound. Based on these results, a HPLC-ICP method combiped with the pre-treatment on Dowex 50 was postulated for the determination of the six arsenic compounds. By this HPLC-ICP method, it was found that the major arsenic compound in the shellfishes analyzed was AB regardless of their feeding habits. In the mid-gut gland of the carnivorous gastropod C. sauliae, AC was also detected as a minor component.
