Determination of organolead compounds by liquid chromatography with on-line extraction and ultraviolet detection

Detection limits by ultraviolet detection in liquid chromatography (LC) for organolead species are improved by the use of a post-column, on-line, continuous liquid-liquid extraction system. Extraction of the organolead species is followed by membrane separation of the extracts from the aqueous mobile phase. Optimization of the merobrane used in the phase separator, ratios of aqueous-to-organic flow rates, extractor dimensions and shape, aqueous salt content, the detection wavelength, and other operational parameters are described. Improvements of detection limits over conventional LC methods with ultraviolet detection range from a factor of 2 for triethyllead chloride, up to a factor of over 10 for trimethyllead chloride. Calibration plots are linear over several orders of magnitude. Extraction efficiencies as a function of the organic extractant flow rate are discussed. The optimized approach is applied to spiked, distilled-water samples.