为研究镉元素在中毒尸体内的分布情况,提出了电感耦合等离子体质谱(ICP-MS)-标准加入法测定中毒尸体中镉元素含量的方法。收集镉中毒尸体的生物体液(心脏全血、胆汁、胸腔积液)和固体组织(心、脾、肺、肾、脑、胃),取6份250μL生物体液或组织匀浆,各加入6个浓度水平的镉标准溶液系列(以铟为内标)和硝酸,在最高消解温度170℃下消解10min,用2%(体积分数)硝酸溶液定容至10mL,采用ICP-MS测定,以镉含量为横坐标,镉与铟的信号强度比值为纵坐标进行线性回归,工作曲线延长线与x轴交点的绝对值为样本中镉的含量。结果显示:中毒尸体中镉含量分布不均匀,肾中镉的质量分数为7200.32ng·g^-1,而脑中镉的质量分数仅为24.88ng·g^-1;镉回收率为82.5%~94.1%,日内和日间测定值的相对标准偏差(n=6)均小于10%。

In order to research the distribution of cadmium in the poisoned corpse, a method for the determination of cadmium in poisoned corpse by inductively coupled plasma mass spectrometry (ICP-MS) with standard addition method was proposed. The biological fluids (including whole heart blood, bile and pleural effusion) and solid tissues (including heart, spleen, lung, kidney, brain and stomach) from cadmium-poisoned corpse were collected. The six biological fluids or solid tissues of 250 μL each were taken, and cadmium standard solution series with 6 concentration levels (indium as the internal standard) and nitric acid were added into each of the above samples. The samples were digested at the highest digestion temperature of 170 ℃ for 10 min, and the digested solutions were made up to 10 mL by 2% (φ) nitric acid solution. ICP-MS was used for the determination, with the content of cadmium as the horizontal coordinate and the signal strength ratio of cadmium to indium as the vertical coordinate for linear regression. The absolute value of the intersection between the extension line of the working curve and the x-axis was the content of cadmium in the sample. It was shown that the cadmium content in poisoned corpse was not evenly distributed, and the mass fraction of cadmium in kidney was 7 200.32 ng·g^-1, while that in brain was only 24.88 ng·g^-1. The recoveries of cadmium were in the range of 82.5%-94.1%, and RSDs (n=6) of the determined values for intra-day and inter-day were less than 10%.