同位素稀释-电感耦合等离子体质谱法测定沉积物中铬和汞

发布时间：2018-05-08 15:00

本文选题：铬 + 汞　；参考：《质谱学报》2017年06期

【摘要】：采用同位素稀释-电感耦合等离子体质谱法(ID-ICP-MS)测定沉积物中铬和汞,分别以铬、汞单元素溶液标准物质标定53 Cr和202 Hg浓缩同位素,将稀释剂与样品混合均匀后,加酸进行消解。对质谱测定过程的数据采集参数进行优化,探究基体效应以及H2和He两种模式对铬测定的影响。为防止汞的记忆效应干扰比值的测定,采用5mg/L EDTA、2.5mg/L Au溶液和3%硝酸交替冲洗管路系统,分别测定了200 Hg/202 Hg和199 Hg/202 Hg两组比值,并比较测定结果。结果显示:积分时间为0.5s时,同位素比值的测定精密度较好,对测定样品进行稀释能够消除质谱及基体效应干扰。H2和He模式均适用于该类样品中铬的测定,200 Hg/202 Hg和199 Hg/202 Hg两组比值对汞的测定结果无显著性差异,沉积物中铬和汞含量分别为81.7 mg/kg和0.471 mg/kg,相对标准偏差分别为0.35%和0.99%。采用美国NIST2709a标准物质进行方法验证,验证结果与标准值一致。该方法准确度高、精密度良好,适用于沉积物、土壤等基体样品中铬和汞的高准确度测定。
[Abstract]:The isotopic dilution and inductively coupled plasma mass spectrometry (ID-ICP-MS) were used to determine chromium and mercury in sediments. The concentrated isotopes of 53 Cr and 202 Hg were calibrated with standard materials of chromium and mercury, and the diluents and samples were mixed uniformly. Add acid for digestion. The data acquisition parameters of mass spectrometry were optimized to explore the matrix effect and the effects of H2 and he on the determination of chromium. In order to prevent the memory interference ratio of mercury, the ratio of 200 Hg/202 Hg and 199 Hg/202 Hg was determined by 5mg/L EDTA 2.5 mg / L au solution and 3% nitric acid alternately flushing pipe system, and the results were compared. The results show that when the integral time is 0.5 s, the precision of isotopic ratio is better. Dilution of samples can eliminate mass spectrometry and matrix effect interference. H2 and he models are suitable for the determination of chromium in this kind of samples. There is no significant difference in the determination results of mercury between 200 Hg/202 Hg and 199 Hg/202 Hg. The contents of Cr and Hg in sediments were 81. 7 mg/kg and 0.471 mg / kg, respectively. The relative standard deviations were 0. 35% and 0. 99%, respectively. The NIST2709a standard material was used to verify the method, and the result was in agreement with the standard value. The method is suitable for the determination of chromium and mercury in sediment, soil and other matrix samples.
【作者单位】：北京化工大学化学工程学院;中国计量科学研究院;山西省计量科学研究院;
【基金】：中国计量科学研究院基本业务费(21-AKY1324)资助
【分类号】：O657.63;X832

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