Rapid determination of lead in infants and young children formula milk powder by direct sample injection-graphite furnace atomic absorption spectrometry

Objective:To establish a method for the determination of lead in formula milk powder for infant and young children by direct dissolution of sample-graphite furnace atomic absorption spectrometry(GFAAS).Methods: The milk powder was dissolved with 0.2% nitric acid,and then lead in the solution was determined by GFAAS with 10%HNO3 as matrix modifier.Results: The linear range of the method was 0 μg/L~50 μg/L and the linear regression equation was Y=2.01×10-3X+4.76×10-6 with the correlation coefficient r=0.9992.The detection limit of the method was 0.015 mg/kg and the RSD was≤7.8% with the recoveries of 94.7%~98.0%.Conclusion: Sample preparation was simple and convenient,and most operation was finished by auto sampler,so the possibility of lead pollution was reduced.The peaktime and type of sample were consistent with the standard,and the background absorption had been eliminated,so the quantitative results were accurate and reliable.