Optimization of methods to assess levels of As, Bi, Sb and Se in airborne particulate matter by FI-HG-ICP OES

A study was undertaken to assess the level of selected trace elements namely, As, Bi, Sb and Se in airborne particulate matter collected on ash-free glass-fibre filters from urban and industrial areas of Argentina. For sample digestion, a simple acid treatment with HCl + HF is proposed with the aim to minimize contamination and reduce sample treatment steps. A flow injection-hydride generation system in combination with inductively coupled plasma optical emission spectrometry was used. While, Se and Bi could be determined directly from the digest, As and Sb needed a pre-reduction with KI, and H3BO3 to avoid the interference of F- ions that may cause losses via volatile compounds such as AsF3 and Sb(V) complexes. Limits of detection (3 sigma) of 0.3 ng m(-3) for As; 0.09 ng m(-3) for Bi, and 0.1 ng m(-3) for Sb and Se were achieved. Precision resulted in better than 6.1% accuracy for all the elements determined. Accuracy test was assessed by means of the certified reference material, NIST 1648 (urban particulate matter).