A method is described for the determination of methylmercury and butyltin compounds in marine sediment and tissue using microwave-assisted acid extraction or digestion and solid-phase microextraction (SPME) followed by analysis using gas chromatography with microwave-induced plasma atomic emission spectrometric detection (GC-MIP-AES). Using the SPME-GC-MIP-AES method, enrichment factors for methylmercury and butyltin compounds of 50-100 were achieved, as compared to the typical hexane extraction, and measurements in marine tissue and sediment matrixes were possible at 1-2 microg/kg (methylmercury) and 10-100 ng/kg (butyltins). The SPME-GC-MIP-AES method was validated using several marine sediment and tissue matrix certified reference materials (CRMs) with certified values for methylmercury and butyltin compounds. The SPME-GC-MIP-AES method was used to measure methylmercury in four marine tissue CRMs ranging from oyster tissue at 13.0 +/- 1.0 microg/kg to fish tissue at 397 +/- 13 microg/kg (as Hg dry mass). Results from the SPME-GC-MIP-AES method were used in conjunction with results from other techniques to assign certified values for methylmercury in oyster, mussel, and fish tissue CRMs. Mono-, di-, and tributyltin were measured in three sediment CRMs at concentration levels of (0.08 +/- 0.03)-(0.35 +/- 0.05) mg/kg (as Sn dry mass).
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.
The Bundesanstalt für Materialforschung und -prüfung, BAM (Federal Institute for Materials Research and Testing) continues to establish a system of primary reference materials to meet the demands of metrological traceability. The materials act as national standards in the field of elemental analysis. For all elements of the periodic table-excepting those that are gases or radioactive-two different kinds of reference materials are being certified. The substances are of very high purity and of defined stoichiometry. Pure elements and metals are used as far as possible. They are certified by determining the trace contents of most elements of the periodic table at very low levels using different trace element analysis methods. Recent application of these methods is described and examples of the certification of some pure metals (copper, iron and lead) are given.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.