Automated Continuous-flow Hydride Generation with Inductively Coupled Plasma Mass Spectrometric Detection for the Determination of Trace Amounts of Selenium(iv), and Total Antimony, Arsenic and Germanium in Sea-water

An automated continuous-flow hydride generation system was developed for the determination of trace amounts of Se IV and total Sb, As and Ge in sea-water using ICP-MS detection. Since the same responses can be obtained between the Sb species Sb V and Sb III , among the As species As V , As III , monomethylarsonic acid and dimethylarsinic acid, and between the Ge species Ge IV and monomethylgermanium, a single Sb, As and Ge species can be used for calibration. A sensitivity enhancement was observed when methanol was used for matrix modification. Matrix modification was also useful for achieving recoveries close to 100% in recovery tests performed on a sea-water sample. Detection limits of 2.2 ng l -1 for Sb as Sb III , 6.5 ng l -1 for As as As V , 2.4 ng l -1 for Ge as Ge IV and 0.5 ng l -1 for Se IV were obtained. For replicate determinations in both a standard solution and a real sea-water sample, the repeatabilities were within 7% (as RSD). The proposed method is rapid (15 samples can be analysed per hour) and sufficiently sensitive to allow trace amounts of Se IV and total Sb, As and Ge to be directly determined in surface sea-water samples taken at a high latitude of the North Pacific Ocean from Japan to Canada.