On-line preconcentration and determination of lead in iron and steel by flow injection-flame atomic absorption spectrometry

A flow injection method has been developed for the determination of lead in steel samples by coupling on-line preconcentration on a lead selective resin, PbSpec(TM), with flame atomic absorption spectrometry. The sample prepared as a nitric acid solution is passed through a column packed with Pb.Spec(TM) The lead retained on the column is then eluted with ammonium oxalate solution and introduced directly into the nebulizer of a flame atomic absorption spectrophotometer. The proposed method was successfully applied to the determination of lead in pure iron certified reference material [0.19 +/- 0.01 ppm (n=6); certified value: 0.2 ppm] and lead-free cutting steel certified reference material [0.0952 +/- 0.0008 % (n=3); certified value: 0.097 %]. The detection limit (3 sigma) was 0.05 mu g of lead.