Analysis of Lead(II) in Human Blood Using Dispersive Liquid-Liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry

Abstract

This paper established a new, rapid and sensitive method for the determination of lead in human blood samples preconcentrated by dispersive liquid-liquid microextraction (DLLME) prior to graphite furnace atomic absorption spectrometry. In the proposed approach, diphenylthiocarbazone (dithizone) was used as a chelating agent, and carbon tetrachloride and ethanol were selected as extraction and dispersive solvents. Important factors that would affect the extraction efficiency had been investigated including the kind and volume of extraction solvent and dispersive solvent, sample pH, the amount of chelating agent, extraction time and centrifugation time. The results showed that the coexisting ions contained in human blood samples had no obvious negative effect on the determination of lead. In the optimum experimental conditions, the limit of detection and enrichment factor were 0.04 ng mL -1 and 123, respectively. The relative standard deviation (RSD) for ten replicate determinations of 10 ng mL -1 was 2.87%. The linearity of method was between 0.10-200 ng mL -1 . The method was successfully applied for the analysis of lead in human blood samples. Keyword: Lead, Graphite furnace atomic absorption spectrometry, Dispersive liquid-liquid microextraction, human blood