Identification of trimethyllead in urine by high-performance liquid chromatography with column switching and chemical reaction detection and by liquid chromatography-mass spectrometry.

Incorporated tetraalkyllead compounds are metabolized in the liver and the highly toxic trialkyllead species are excreted via the urine. The procedure for the determination of these metabolites in urine consists of solid-phase enrichment, reversed-phase pre-column high-performance liquid chromatography (HPLC) and chemical reaction detection. As urine is a very complex matrix, it must be questioned whether the retention time alone is a sufficient criterion for the identification of the analytes. For the trimethyllead ion the validity of the results was examined by selectivity checks of the chemical reaction detector, by the application of different stationary and mobile phases in single and dual pre-column HPLC systems and by the use of thermospray LC-mass spectrometry as an independent method. The results demonstrated that the recommended method is accurate for the determination of trimethyllead in urine samples.

Determination of trialkyllead species in water samples.

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 500 ml sample volume, are 15 pg/ml and 20 pg/ml for trimethyl- and triethyllead resp. The standard deviation for repeated analysis of a sample containing 90 pg 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.