石墨炉原子吸收光谱法测定食盐中的铅

Method for Determination of Lead in Salt by Graphite Furnace Atomic Absorption Spectrometry

目的:以1%磷酸二氢铵+1%抗坏血酸为基体改进剂,建立石墨炉原子吸收光谱法测定食盐中铅的方法。方法:食盐用1%硝酸直接溶解,以1%磷酸二氢铵+1%抗坏血酸为基体改进剂,石墨炉原子吸收光谱法测定。结果:铅标准溶液浓度为0~20μg/L,标准曲线的线性相关系数r为0.999 2,方法检出限为0.012 mg/kg,样品加标回收率为92%~96%,相对标准偏差<5.0%。结论:本方法方便快捷,检出限、回收率、精密度均满足食盐中铅的检测。

Objective： To establish a method for the determination of lead in salt by graphite furnace atomic absorption spectrometry with 1% ammonium dihydrogen phosphate ＋ 1% ascorbic acid as matrix modifier. Methods： Salt was directly dissolved in 1% nitric acid and determined by graphite furnace atomic absorption spectrometry with 1% ammonium dihydrogen phosphate ＋ 1% ascorbic acid as matrix modifier. Results： The concentration of lead standard solution was 0～ 20 μg/L. The linear correlation coefficient r of the standard curve was 0.999 2. The detection limit of the method was 0.012 mg/kg. The recoveries of the standard addition were 92%～96%, and the relative standard deviation was〈5.0%. Conclusion： The method is convenient and rapid, and the detection limit, recovery rate and precision are all suitable for the detection of lead in salt.