Sensitive speciation analysis of lead in environmental waters by capillary gas chromatography microwave-induced plasma atomic emission spectrometry
Résumé
Optimization of microwave-induced plasma atomic emission detection for the speciation of organolead compounds in water samples is described. The absolute detection limits achieved vary from 0.02 to 0.1 pg (as Pb) and are dependent on the volatility of the species determined. Two procedures for the separation and enrichment of organolead in water samples were evaluated. Ionic organolead species were extracted as their diethyldithiocarbamate complexes either with one portion of hexane at pH 8 or twice with pentane at pH 9, with preconcentration in the latter instance by rotary evaporation of the solvent. The detection limits obtained were down to 2 and 0.1 ng l-1, respectively for 100-ml samples. Propylation and butylation were compared for derivatization of organolead species in the extracts. Examples of results for rain and tap water analyses are given.