石墨消解-微波消解法测定乳粉中总砷、总汞、铅和镉

目的建立石墨消解-微波消解法测定乳粉中的总砷、总汞、铅和镉含量的分析方法。方法样品经石墨加热预消解,采用微波消解法前处理,并采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定乳粉中的总砷、总汞、铅和镉含量。结果总砷、总汞、铅和镉的平均加标回收率为94.4%?108.3%,精密度的相对标准差(relative standard deviation,RSD)为1.1%?4.6%,方法检出限分别为4.4、4.8、4.9、0.6?g/kg。乳粉质控样和考核样中总砷、总汞、铅和镉的测定结果均在参考值范围内,结果均为满意。结论该方法操作简便,重现性良好,测定结果准确、可靠,适用于乳粉中总砷、总汞、铅和镉的含量测定。

Determination of total arsenic, total mercury, lead and cadmium in milk powder by graphite digestion-microwave digestion

Objective To establish a method for the determination of the total arsenic, total mercury, lead and cadmium in milk powder by graphite digestion-microwave digestion. Methods The samples were dealt with microwave digestion after graphite heating digestion, and the total arsenic, total mercury, lead and cadmium in milk powder were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Results The recovery rates of total arsenic, total mercury, lead and cadmium were from 94.4% to 108.3%, and the relative standard deviations (RSDs) of the precision were from 1.1% to 4.6%. The detection limits were 4.4, 4.8, 4.9 and 0.6 ?g/kg, respectively. The determination results of the total arsenic, total mercury, lead and cadmium in quality control material and test materials of milk powder were in the ranges of reference values, which were satisfactory. Conclusion This method is convenience for the operation, with good reproducibility, accuracy and precision, which is suitable for the determination of total arsenic, total mercury, lead and cadmium in milk powder.