Preconcentration and determination of Sn- and Pb-organic species in environmental samples by SPME and GC-AED

Abstract

A new sample preparation and preconcentration technique - solid phase microextraction (SPME) - is reported for the application of several tinorganic 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 as adsorption and desorption time, stirring rate and temperature has been investigated. The determination has been performed by GC coupled with atomic emission detection (AED). After optimization of the conditions 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 preconcentration. Values of about 10 can be reached. A detection limit of 0.09 pg Sn and 0.08 pg Pb can be achieved under optimized conditions. The proposed procedure has been successfully applied to the analysis of organotin compounds in various slurry samples.

Determination of Organotin Compounds in Environmental Samples

“…There are some novel approaches useful for the analysis of organotins compounds. For example, an alternative technique, SPME, a solvent free analytical process 63,64 and a coupling of multicapillary GC 99 with sensitive element-selective detection have been reported to be successful to the analysis of organotin compounds in environmental samples.…”

“…Solid-phase microextraction (SPME) techniques were applied by Moens et al 63 and Tutschku et al 64 to determine butyltin compounds in aqueous samples. The in situ derivatized compounds with NaBEt4 were sorbed on SPME fiber and determined by GC coupled with AED or ICP-MS.…”

“…The in situ derivatized compounds with NaBEt4 were sorbed on SPME fiber and determined by GC coupled with AED or ICP-MS. Detection limits were 0.09 pg Sn with AED and between 0.34 -2.1 ng Sn/l with ICP-MS. 64 Multicapillary column GC/MIP-AES was attempted by Pereiro et al 65 for the fast speciation of butyl-and phenytin compounds in sediments and biological materials. Ethylated butyltin compounds could be separated isothermally within 30 s. Careful optimization of the pressure and temperature programming allowed a comprehensive organotin speciation including phenyltin compounds within 2.5 min, as shown in Fig.…”

Applications of solid phase microextraction for the determination of metallic and organometallic species

“…Tutschku et al [35] preconcentrated and determined organotin and organolead species in environmental samples by SPME and GC-AED. Analytical variables of the extraction such as adsorption and desorption time, stirring rate, and temperature were investigated.…”

“…The fiber was immersed for 30 min in the sample solution with constant stirring to assure proper extraction of the analytes. It is reported that organotins can also be analyzed in the presence of other metals [15,21,24,26,29,32,35,37,38,49].…”