Comparison of two derivatization reagents for the simultaneous determination of organolead and organomanganese compounds using solid-phase microextraction followed by gas chromatography with atomic emission detection

摘要

Two procedures for the simultaneous determination of organolead (tetraethyllead, triethyllead and trimethyllead) and organomanganese compounds (cyclopentadienyl manganese tricarbonyl (CMT) and methylcyclopentadienyl manganese tricarbonyl (MMT)) are studied. Both procedures involve sample preconcentration by solid-phase microextraction and capillary gas chromatography coupled to atomic emission detection, the main difference being the derivatizing agent used for the ionic alkylated lead species: sodium tetrapropylborate (NaBPr_4) and sodium tetraphenylborate (NaBPh _4). The parameters affecting the derivatization and preconcentration steps, chromatographic separation as well as detection of the compounds were optimized. Higher sensitivity was attained for all compounds with the method involving propylation derivatization. In this case, detection limits ranged between 0.04 and 0.1 ng L~(-1), depending on the compound. Detection limits of between 0.1 and 24.5 ng L~(-1) were obtained, when using phenylation derivatization. A low CMT concentration was found in one of the seawater samples analyzed.