Determination of trace bismuth by flow injection-hydride generation collection-atomic absorption spectrometry

Bismuth hydride gas was collected on-line and determined via a new flow injection-hydride generation collection-flame atomic absorption spectrometry system. The performance of the gas-liquid separator, hydride gas collection time, acidity of the sample solution, NaBH(4) concentration, and the effects of concomitant interferents were investigated to optimize the conditions of this new method. Interferences from concomitant elements were investigated, and recoveries of 94.7-105.3% for 10 ng mL(-1) Bi were obtained after the addition of 0.2% ascorbic acid-thiourea masking reagents. The sensitivity of this new method was one order of magnitude higher than the continuous flow-hydride generation-flame atomic absorption method with a detection limit of 0.25 ng mL(-1) and a precision of 2.3%. The method was evaluated by determining trace bismuth in standard biological reference material human hair GBW07601, and the results were consistent with the certified value. The proposed method was then employed to determine trace bismuth in ten colored gelatin samples; recoveries of 94.2-105.8% were obtained.