目的 建立微波消解-ICP-MS(电感耦合等离子体质谱)法同时测定食用淡水螺中铬(Cr)、镍(Ni)、砷(As)、镉(Cd)、铅(Pb)5种污染物元素含量。方法 以硝酸为消解液,取适量样品,经微波消解处理后稀释定容,联合ICP-MS,直接上机分析食用淡水螺中5种污染物元素,通过内标元素⁴⁵Sc、⁸⁸Y、¹¹⁵In、²⁰⁹Bi校正基体干扰和漂移,根据标准曲线定量待测元素含量。结果 微波消解-ICP-MS法测定Cr、Ni、As、Cd、Pb 5种污染物元素在0~100 μg/L范围内呈良好的线性关系,标准曲线相关系数(r)均≥0.999 4,方法检出限≤1.63 μg/kg,定量限≤4.95 μg/kg,相对标准偏差(RSD)≤4.24 %,各元素加标样品加标回收率在85.71%~115.00%之间。结论 微波消解-ICP-MS法操作简单快速、灵敏度高、重现性及稳定性良好,适用于食用淡水螺中Cr、Ni、As、Cd、Pb 5种污染物元素含量的同时测定。

Objective To establish a microwave digestion-ICP-MS (inductively coupled plasma mass spectrometry) method for the simultaneous determination of Cr,Ni,As,Cd and Pb pollutant element in edible freshwater snails. Methods Take an appropriate amount of sample with nitric acid as the digestion solution,and dilute it to volume after microwave digestion treatment.Direct on-line analysis of five contaminant elements in edible freshwater snails by combined ICP-MS.Correction for matrix interference and drift by internal standard elements ⁴⁵Sc,⁸⁸Y,¹¹⁵In and ²⁰⁹Bi.Quantify the content of the element to be measured according to the standard curve. Results The microwave digestion-ICP-MS method demonstrated a good linear relationship for the determination of five pollutant elements (Cr,Ni,As,Cd,Pb) within the range of 0 μg/L to 100 μg/L.The correlation coefficients (r) of the standard curves were all≥0.999 4.The detection limits of the method were ≤1.63 μg/kg,and the quantification limits were≤4.95 μg/kg.The relative standard deviations (RSD) were≤4.24%.The spike recovery rates for each element in the spiked samples ranged from 85.71% to 115.00%. Conclusion The microwave digestion-ICP-MS method is simple and fast to operate,with high sensitivity,good reproducibility,and stability.It is suitable for the simultaneous determination of the content of five pollutant elements (Cr,Ni,As,Cd,Pb) in edible freshwater snails.