电感耦合等离子体质谱法测定奶粉中镉含量

Determination of cadmium in milk powder by inductively coupled plasma mass spectrometry

目的建立电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定奶粉中镉含量的分析方法。方法采用微波消解-电感耦合等离子体质谱法测定奶粉中镉的含量,进行方法的检出限、精密度、加标回收、仪器比对、方法比对、不确定度评估等实验,并且以能力验证的反馈结果对方法的准确性进行评价。结果该方法在0.5~50μg/L范围内线性关系良好,回归方程为Y=0.02545C+0.00030,相关系数0.99999,检出限为0.0008mg/kg,加标回收率在96.9%~100.2%范围,仪器比对和方法比对结果满意,能力验证奶粉中镉含量的反馈结果 Z值为-0.06。结论本方法线性关系良好,效率高,准确性好,可用于奶粉中的镉含量的测定。

Objective To establish a method for the determination of cadmium in milk powder by inductively coupled plasma mass spectrometry(ICP-MS).Methods The content of cadmium in milk powder was determined by microwave digestion-inductively coupled plasma mass spectrometry.The limit of detection, precision, standard addition, instrument comparison, method comparison, uncertainty evaluation and other experiments were carried out.The accuracy of the method was evaluated by the feedback results of capability certification.Results This method has a good linear relationship in the range of 0.5-50 μg/L, the regression equation was Y=0.02545C+0.00030, with a correlation coefficient of 0.99999, the limit of detection was 0.0008 mg/kg, the recoveries of standard addition were in the range of 96.9%-100.2%.The instrument comparison and method comparison results were satisfactory.The Z value of the feedback result of capacity verification of cadmium content in milk powder was-0.06.Conclusion This method has good linearity, high efficiency and good accuracy, which can be used for the determination of cadmium content in milk powder.