Flow injection solid phase extraction with Chromosorb 102: determination of lead in soil and waters by flame atomic absorption spectrometry

A flow-injection, solid-phase extraction, preconcentration method was devel oped for the determination of lead in soil and water samples by flame atomi c absorption spectrometry. Lead, in the form of the diethyldithiocarbamate complex, was retained on a miniature column of Chromosorb 102 from buffered sample solutions. Several parameters governing the efficiency and throughp ut of the method were evaluated including pH, eluent composition, volume an d flow rate. The complex retained from pH 9.0 (ammonium acetate) solutions was eluted with 176 mu l of ethanol, at 4.2 ml min(-1) into the nebulizer-b urner system of the spectrometer. The detection limit was 2 mu g 1(-1) for preconcentration at 2.2 ml min(-1) for 120 s. The relative standard deviati on (R.S.D) was less than 4% for concentrations down to 400 mu g 1(-1) The p rocedure was validated by the analysis of NIST standard reference material 2711 (Montana Soil) which contains lead at a concentration of 1162 mu g g(- 1). Recoveries of spike additions (100-400 mu g 1(-1)) to artificial sea wa ter and tap water were quantitative. (C) 2000 Elsevier Science B.V. All rig hts reserved.