DETERMINATION OF LEAD IN AEROSOL SAMPLES COLLECTED ON GLASS FIBER FILTERS BY AN IMPROVED ATOMIC ABSORPTION SPECTROMETRY METHOD

This paper presents a simple, reliable, economical, safe, accurate and reproducible method for atmospheric aerosol lead determination in glass fiber filters, consisting on an acid digestion procedure and atomic absorption spectrometry quantification. The acid digestion is accelerated by the use of a microwave oven with capped Teflon PFA vessels, and a two steps power and time program. The mixture of 10 mL HNO₃ and 1 mL HF was selected between many tries, for both economic and environmental reasons. The use of direct standards for quantification is proposed instead of added standards on filters, using background correction (deuterium lamp). The filter lead content quantification was carried out through blank analyses. Lead determinations were carried out then in 2629 samples of atmospheric aerosol at three sampling points in the city of Cartagena (Spain), from 1990 to 1994. We present the annual average of these values for each year and sampling location.