石墨炉原子吸收法测定食用油中铅的方法研究

Research on the determination of lead in edible oil by graphite furnace atomic absorption spectrometry

目的建立并优化微波消解-石墨炉原子吸收光谱法测定食用油中铅的方法。方法应用优化微波消解方法处理食用油样品,优化基体改进剂加入条件,调整横向塞曼石墨炉原子吸收光谱法测定的最好状态直接测定样品中痕量铅。结果选定了最佳测量条件,该方法灵敏度、精密度均能满足检测工作的需要。本法线性方程为：y=0.010 39x＋0.014 0,相关系数为0.998。对铅的最低检出量为1.5 pg,在加标5μg/kg和10μg/kg时其回收率为89.0%~101.2%。用该法测杭州市售10份食用油中铅含量,1份超标;测定3份多次使用后的食用油中铅含量,均超标。结论本法简便、快速、准确,灵敏度和精密度高,分析结果可靠。适用于食用油中痕量铅的测定。用本法测定杭州市售食用油显示整体状况良好,多次使用后的食用油存在问题。

Objective To establish and optimize a new method for the determination of lead in edible oil by microwave digestion-graphite furnace atomic absorption spectrometry. Methods Optimization microwave digestion method was applied for processing edible oil samples,to optimiz the matrix modifier join condition,and adjust the best state of Zee- man GFAAS. determination for the direct determination of trace lead. Results Under the best condition,the sensitivity and precision were suitable for the determination. Act linear equation was y = 0. 010 39 x ＋ 0. 014 0,correlation coefficient was 0. 998. The minimum detectable amount of lead was 1. 5 pg,and when spiked 5 μg / kg and 10 μg / kg,recoveries rates was of 89. 0%- 101. 2%. The method was used to detect lead content in 10 cases of market- sale edible oil,there was 1 case of lead contents over standard,and all cases of three times used edible oil were all contents over standard. Conclusion This method is simple,quick,accurate,sensitive with high precision and reliable results. It is suitable for measuring lead in edible oil. The hygienic index situation of lead in edible oil sold is good in Hangzhou with this method,and the used edible oil is disappointed.