METHOD VALIDATION FOR DETERMINATION OF LEAD IN WATER BY ATOMIC ABSORPTION SPECTROSCOPY WITH ION IMPRINTED POLYMER MATERIAL

Abstract

The procedure for the determination of lead in water samples by atomic absorption spectroscopy using flameless atomization technique GF-AAS combined with Pb²⁺ ions imprinted polymer (IIP) material has been successfully validated. The Pb²⁺ ions imprinted polymer material was synthesized using 1-mercaptoctane; methacrylic acid; Pb(NO₃)₂; AIBN and EDGMA 60 ^oC in 5 hours under nitrogen atmosphere. The characteristics of the materials were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction techniques. Pb²⁺ ions in water samples were re-imprinted into the IIP material, then desorbed with HNO₃ solution and determined by the GF-AAS techniques. Under optimized parameters of GF-AAS instrument, the linear calibration graph was in the range of 5÷120 µg/L with R²=0.9977. The limit of detection and limit of quantification were 1.11 µg/L and 3.32 µg/L, respectively. Repeatability of 10 µg/L, 20 µg/L, 30 µg/L concentrations was 9.75%; 9.07%; 7.22%, respectively. The reproducibility performed on different days with above three concentrations was 8.69%, 8.32%; 7.38%, respectively. The recovery efficiency of the method was in the range of 89.69 ÷ 92.97%. The research method was applied to analyze the trace of lead content in water samples in HoChiMinh City, Long An Province and evaluated according to the standards of the Ministry of Health and the Ministry of Natural Resources and Environment.