Determination of Trialkyllead Species in Water Samples

Abstract

An analytical compound procedure is described for the determination of trimethyl- and triethyllead in water samples like rain, melted snow, and surface waters. The method consists of an enrichment step (adsorption onto and elution from silica gel), a chromatographic separation with column switching (HPLC including pre-column enrichment). and a spectrophotometric detection (chemical reaction detector). The detection limits for the whole procedure, starting with 500ml sample volume, are 15pg/ml and 20pg/ml for trimethyl- and triethyllead resp. The standard deviation for repeated analysis of a sample containing 90pg Et₃Pb⁺/ml is calculated to ±4%. The method also covers the analysis of the chemically mixed trialkyllead species Me₂EtPb⁻ and MeEt₂Pb⁻. The investigation of several water samples taken from different locations shows the presence of trimethyl- and triethyllead in the concentration range of 20–100 pg/ml.