Vortex-assisted Dispersive Liquid-Liquid Microextraction of Pb (II) as 2-hydroxypyridine-3-carboxylic Acid Chelates From Food and Water Samples Prior to Flame Atomic Absorption Spectrometric Determination

摘要

A vortex-assisted dispersive liquid-liquid microextraction method for the preconcentration and separation of lead(H) as 2-hydroxypyridine-3-carboxylic acid chelates is presented. CCl4 as the extraction solvent and ethanol as the dispersive solvent were used. The analytical parameters optimized included pH, amount of 2-hydroxypyridine-3-carboxylic acid, type and volume of extraction solvent, type and volume of dispersive solvent, sample volume, etc., which affect the extraction efficiency of lead(II). The influence of some matrix ions was also investigated. The detection limit for lead(II) was 8.30 mu g L-1 for liquid samples and 0.49 mu g g(-1) for solid samples. The preconcentration factor of the method was 30. The validation of the method was checked by the analysis of the certified reference materials TMDA-64.2, TMDA 53.3, and SPS-WW2 Waste-water and GBW07425 soil, BCR-146 R Sewage Sludge, HR-1 Harbour Sediment, and DC73349 Bush Branches and Leaves. The proposed microextraction method was applied to the determination of lead in some natural water, food, soil, and sediment samples.