Determination of lead in atmospheric aerosols by electrothermal atomisation atomic absorption spectrometry with direct introduction of filters into the graphite furnace

Abstract

An electrothermal atomisation atomic absorption spectrometric (ETA-AAS) procedure for the determination of lead in atmospheric aerosols has been evaluated, in which small discs (2 mm diameter) cut from a filter, on which atmospheric aerosols had been collected by classical equipment, were introduced into the graphite furnace without any previous treatment. The pyrolysis and atomisation temperatures were fixed at 350/750 °C (15/40 s) and 2080/2080 °C (0/10 s). The 283.3-nm line was used for the determination of lead. Under these conditions, the procedure gave the following results for the determination of lead (expressed as mass per filter area): range, up to ca. 25 ng cm–2; detection limit, ca. 0.7 ng cm–2; precision (RSD), 9.3% at 7.3 ng cm–2 and 6.3% at 10.2 ng cm–2. The accuracy of the procedure was confirmed by the acceptable agreement of parallel results obtained by the described procedure and by ETA-AAS determinations on liquid samples prepared by wet digestion of larger pieces of the same filters.