PRECONCENTRATION AND DETERMINATION OF SN-ORGANIC AND PB-ORGANIC SPECIES IN ENVIRONMENTAL-SAMPLES BY SPME AND GC-AED

A new sample preparation and preconcentration technique - solid phase microextraction (SPME) - is reported for the application of several ti norganic compounds and tetrabutyllead in aqueous samples. The solvent- free procedure is rapid in comparison with liquid-liquid extraction or SFE but also sensitive. Analytical variables of the extraction such a s adsorption and desorption time, stirring rate and temperature has be en investigated. The determination has been performed by GC coupled wi th atomic emission detection (AED). After optimization of the conditio ns of SPME a calibration was realized on the basis of a multicomponent standard solution, prepared by ethylation of organotin salts directly in the sample using sodium tetraethylborate (NaBEt(4)) without prior separation of the analytes from the matrix. The method permits preconc entration. Values of about 10 can be reached. A detection limit of 0.0 9 pg Sn and 0.08 pg Pb can be achieved under optimized conditions. The proposed procedure has been successfully applied to the analysis of o rganotin compounds in various slurry samples.