title: Speciation of alkyllead in aqueous samples with application of liquid membrane probe for extraction and preconcentration.
abstract: Lead is known to be toxic, especially in its organic forms (organolead, OL). In the environment tetraalkyllead species are rapidly degraded by sunlight and atmospheric constituents like ozone or hydroxyl radicals. Such breakdown yields the soluble forms such as trialkyllead and dialkyllead and finally ionic lead species. The liquid membrane extraction probe (LMP) device has been developed and used as an extraction and preconcentration tool for the speciation analysis of organolead compounds by GC/MS. It allows analysis of OL species at low concentrations in complicated matrices of environmental samples. The effect of pH, stirring rate, and time that influence the extraction efficiency of OL extraction by the LMP method were optimized. The transformation of tetramethyllead in aqueous media at different concentrations of major ions K(+), Na(+), Ca(2+), Mg(2+), Cl(-), SO(4)(2-) and the application of LMP to environmental samples are presented. It was found that degradation of tetramethyllead takes between 24 and 37 days. The detection limit (LOD) of the method for all organolead species investigated is around 4.7 microg/L, with a limit of quantitation of 15 microg/L.
authors.affiliation: School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa. ewa.cukrowska@wits.ac.za
authors.forename: Ewa M
authors.initials: EM
authors.lastname: Cukrowska
authors.forename: Hermogène
authors.initials: H
authors.lastname: Nsengimana
authors.forename: Luke
authors.initials: L
authors.lastname: Chimuka
mesh_terms: D000478:Alkylation; D008401:Gas Chromatography-Mass Spectrometry; D007854:Lead / Q000737:chemistry* / Q000302:isolation & purification; D015335:Molecular Probes; D012995:Solubility; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D015335:Molecular Probes; D014874:Water Pollutants, Chemical; D007854:Lead