Antimony speciation in road dust and urban particulate matter in Valparaiso, Chile: Analytical and environmental considerations

In this study we develop an analytical methods for the determination of total Sb, Sb(V) and Sb(III) in road dust and airborne particulate matter (APM) by HPLC-HG-AFS. For total Sb determination, samples were digested with 6 mL of HNO3 and 2 mL of HBF4 in closed microwave digestion system at 200 °C in 30 min, trueness was determined by using APM certified reference material NIST 1648a. For Sb(V) and Sb(III) determination, oxalic acid 100 mmol L-1 in 1% w/v ascorbic acid at 70 °C in closed vessel microwave extraction was chosen as extraction procedure. Analytical methods were applied to airborne particulate matter (< 10μm), and road dust (< 37 μm) samples. An enrichment of antimony from 4 to 10 times higher was detected in road dust in Valparaiso, Chile, which correlates with the enrichment reported by our group in 2009 in the blood. On the other hand up to 70% of total antimony extracted from road samples was Sb(III) indicating an anthropogenic origin of this element.