Determination of cadmium and lead in aqueous environmental samples after complexation and microextraction onto the surface of an empty solvent-impregnated polypropylene fibre coupled with electrothermal AAS

A procedure based on polypropylene hollow-fibre preconcentration coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for the determination of cadmium and lead in seawater, wastewater, tap water and lake water samples. The n-octanol was immobilised in the pores of the polypropylene hollow fibre, which was used as the liquid sorption membrane negating the need for acceptor liquid phase in the lumen. The metal ions were extracted from water samples onto the impregnated fibre, as ammonium pyrrolydine dithiocarbamate (APDC) complexes, and then back-extracted into a small volume of 0.1 mol L⁻¹ HNO₃. The main extraction-related parameters were properly evaluated and an interference study was carried out. Linear regression lines were plotted and replicate analyses of real samples revealed that the proposed method is precise and accurate, able to be applied in routine analysis with detection limits of 4 ng L⁻¹ and 12 ng L⁻¹ for Cd and Pb, respectively.