Direct Determination of Lead in Mouse Blood by Graphite Furnace Atomic Absorption Spectrometry Optimized by Response Surface Methodology

[Objective] To explore a method for direct determination of lead in mouse blood by graphite furnace atomic absorption spectrometry(GFAAS) with optimization using response surface methodology. [Methods] After blood samples were diluted with 0.5% Triton X-100 solution, lead in blood was directly determined by GFAAS using a mixture solution of 0.05% PdCl2 and 0.1% HNO3 as modifier. The effects of matrix modifier dosage, ashing temperature, and atomization temperature on absorbance were examined by central composite design and response surface methodology. [Results] The optimum extraction conditions were as follows: ashing temperature, 760.85℃; atomization temperature, 2 486.80℃; and dosage of matrix modifier, 0.97 mL. Under the optimal conditions, the value of detection limit for Pb was 0.204 μg/L, and the relative standard deviation(RSD) for six replicate determinations of Pb was 1.76%. Lead in blood of mice was successfully detected at a concentration of 82.1 μg/L, and the recoveries were 96.5%-98.4%. [Conclusion] The method is simple, rapid, and accurate by direct injection without digestion or centrifugation, which can be applied to lead determination in mouse blood.