Graphite furnace atomization behaviour of lead contained in clinical and environmental materials in the presence of palladium-induced isoformation and citric acid

A simple stabilized temperature platform furnace (STPF)-electrothermal atomic absorption spectrometric (ETAAS) method was developed for the determination of lead in complex samples using a composite palladium-citric acid isoformer. Analyte isoformation solutions contained 0.5 mg palladium per litre and 2 per cent m/v citric acid, 0.6 per cent m/v ammonium hydrogen phosphate, 0.3 per cent m /v magnesium nitrate and 8 per cent m/v citric acid. An appearance time of 1.56 seconds was obtained for atomic lead in samples and aqueous standards when 200 ug (for palladium) and 800 ug (for phosphate-magnesium) of citric acid were used. Data are presented for the elucidation of the mechanism of atomization of lead in real materials. The limit of detection was 0.1 ug lead per litre for a 10 ul injection of test solution and the characteristic mass was 13 pg. Recoveries of lead from human serum, freeze dried urine, blood, pond sediment, Chlorella, tea leaves, vehicle exhaust particulates and Sargasso reference materials ranged from 94-104 per cent. The proposed method was used to establish the lead levels of 40 healthy adults from Maracaibo City. These were 148, 326, 10.2 and 7.8 ug per litre, respectively, for whole blood, red blood cells, urine and bone. The lead content of the city's drinking water supply was 0.1 ug per litre or less. There are 50 references.