Determination of thallium in sea-water by flow injection hydride generation isotope dilution inductively coupled plasma mass spectrometry

A simple and inexpensive laboratory-built vapor generator was used with ind uctively coupled plasma mass spectrometry (ICP-MS) for the determination of Tl in sea-water samples. The application of vapor generation (VG) ICP-MS a lleviated the non-spectroscopic interferences encountered when the conventi onal pneumatic nebulizer was used for sample introduction. The concentratio n of Tl was determined by the isotope dilution method. The isotope ratio of Tl was calculated from the peak area of each injection peak. The repeatabi lity of the peak area and isotope ratio determinations of seven consecutive injections of 1 ng ml(-1) Tl solution was 2.8% and 2.4%, respectively. Thi s method has a detection limit of 0.01 ng ml(-1) for Tl in sea-water. This method was applied to determining Tl in CASS-3 nearshore sea-water referenc e sample, NASS-4 open ocean sea-water reference sample and sea-water sample s collected from the Kaohsiung area. The result for the reference sample CA SS-3 agreed satisfactorily with the reference value. Results for other samp les analyzed by different quantitation methods agreed satisfactorily. Preci sion was better than 10% for most of the determinations.