Determination of available cadmium in soil by inductively coupled plasma mass spectrometry
LI Yuan, ZI Yushu, LIU Chao, LIU Jinliang, YUE Zhonghui
Research Institute No. 230, CNNC, Changsha 410007, China
摘要：建立电感耦合等离子体质谱（ICP-MS）仪测量土壤样品中有效态镉的方法。为了提高ICP-MS法测量的稳定性和准确度，优化样品粒度、称样量、振荡时间等条件，以二乙三胺五乙酸-三乙醇胺-氯化钙混合溶液（DTPA）为提取剂（固液比为1∶12.5），元素铑为内标，ICP-MS仪测定有效态镉的含量。有效态镉的线性范围为0～0.200 mg/L，线性相关系数为0.999 8，检出限为0.000 9 mg/kg。测定结果的相对标准偏差为1.56%～3.16%（n=6）。用该法测定国家标准物质土壤中的有效态镉，测定值与标准值基本一致，相对误差为-2.92%～3.13%。该方法减少了样品的浪费，提高了工作效率，增加了测量稳定性，测定结果准确可靠，在检测大批量土壤有效态镉时更具有优越性。
Abstract：The method for determination of available cadmium in soil samples by inductively coupled plasma mass spectrometer (ICP-MS) was established. In order to improve the stability and accuracy of ICP-MS measurement, the weighing and oscillation time of samples were optimized. Diethylenetriamine pentaacetic acid-triethanolamine-CaCl2 mixed solution was used as extractant (solid-liquid ratio was 1∶12.5), Rh was used as internal standard, and available cadmium was determined by ICP-MS. The linear range of available cadmium was 0-0.200 mg/L with the linear correlation coefficient of 0.999 8, the detection limit was 0.000 9 mg/kg, and the relative standard deviation was 1.56%-3.16%(n=6). The determination result of available cadmium in the national standard substance soil determined by using this method was nearly in accord with standard values with the relative errors from -2.92% to 3.13%. The method reduced the waste of samples, improved the work efficiency, increased the stability of measurement, and the results were accurate and reliable which applicable for detecting available cadmium in large quantities of soil sample.
Keywords：inductively coupled plasma mass spectrometry; available cadmium; soil; diethylenetriamine pentaacetic acid-triethanolamine-CaCl2 mixed solution
李源，字雨姝，刘朝，等.电感耦合等离子体质谱法测定土壤中有效态镉[J].化学分析计量，2019，28(5)：14-18. LI Y，ZI Y S，LIU C，et al. Determination of available cadmium in soil by inductively coupled plasma mass spectrometry[J]. Chemical analysis and meterage，2019，28(5)：14-18.