沉积物中重金属元素钴、铜、铅的酸溶–电感耦合等离子体质谱测定方法

Simultaneous Determination of 3 Heavy Metal Elements (Co, Cu, and Pb) in Sediment by Acid Dissolution-ICP/MS

摘要: 沉积物记录着水体环境变化的丰富信息，其中重金属的含量是评价水体环境的重要指标。文章应用酸溶–电感耦合等离子体质谱法建立了沉积物中常见金属元素钴、铜和铅的检测方法，以内标法定量，计算出3种元素的方法检出限分别为0.01 mg∙kg⁻¹、0.19 mg∙kg⁻¹和0.27 mg∙kg⁻¹，线性方程相关系数分别是0.9997、1和1，利用该方法分析了3种沉积物有证标准物质GBW07308a (GSD-8a)、GBW07365 (GSD-22)和GBW 07362 (GSD-19)，测定值与参考值吻合较好，均在相应标准物质不确定度范围内。精密度实验中钴、铜、铅的相对标准偏差分别为3.93%~6.45%、2.22%~5.34%和2.58%~5.18%，正确度范围为 0.35%~3.69%，方法的精密度和准确性良好、检出限低。用建立的方法测定了某区域内50个沉积物样品，结果表明，本方法符合沉积物中3种重金属元素含量的测试要求，能满足实际环境中水系沉积物中3种重金属元素含量快速、准确测试的需要。方法高效、快速、可行。

Abstract: Sediments record plentiful information about changes in the water environment. The content of heavy metals in the sediment is an important index to evaluate the water environment. The article developed a detection method for common metal elements Co, Cu, and Pb in sediments using acid dissolution-inductively coupled plasma mass spectrometry (ICP-MS), quantifying the elements with the internal standard method. The detection limits for these three elements were calculated to be 0.01 mg∙kg⁻¹ for Co, 0.19 mg∙kg⁻¹ for Cu, and 0.27 mg∙kg⁻¹ for Pb, with correlation coefficients for the linear equations being 0.9997, 1, and 1, respectively. The method was applied to analyze three sediment certified reference materials, GBW07308a (GSD-8a), GBW07365 (GSD-22), and GBW07362 (GSD-19), yielding values that were in good agreement with the reference values and within the uncertainty range of the corresponding standard materials. In the precision experiment, the relative standard deviations for Co, Cu, and Pb were 3.93%~6.45%, 2.22%~5.34%, and 2.58%~5.18%, respectively, with accuracy ranging from 0.35% to 3.69%. The method demonstrated good precision and accuracy with low detection limits. It was used to test 50 sediment samples from a certain area, indicating that the method meets the testing requirements for the content of these three heavy metals in sediments and fulfilling the need for rapid and accurate testing of these heavy metal contents in aquatic sediments in real environmental situations. The method is efficient, rapid, and feasible.