无火焰原子吸收测定环境样品中的痕量铅

摘要

以琼脂为悬浮体进样,以磷酸二氢铵为基体改进剂,研究了悬浮液的稳定性和基体改进效应对于石墨炉原子吸收法测定环境中痕量铅的影响.结果表明,悬浮液浓度为0.15%,改进剂浓度为1.0%,灰化和原子化温度分别为800℃和2200℃时能精确测定环境样品中的铅含量.在此条件下,用标准加入法测定土壤和藕粉中的铅含量分别为25.47μg/g和0.6μg/g.%Trace lead in the environment was determined by atomic absorption spectrometry using agar as suspending agent and (NH4 )2 HPO4 as matrix modifier.The stability of suspending agent and effect of ma-trix modifier were investigated.The research shows that 0.15% agar and the 1.0% (NH4 )2 HPO4 as a modifier,800 ℃ cineration temperature and 2200 ℃ atomization temperature are in practical use.The analytical results of the standard reference samples are consistent with the certified values.The lead con-tent of the soil and lotus root starch are 25.47 μg/g and 0.6 μg/g separately using standard curve meth-ods.