超级微波消解-碰撞反应池电感耦合等离子体质谱法测定蔬菜中21种元素含量

Determination of 21 kinds of elements content in vegetables by inductively coupled plasma mass spectrometry with super microwave digestion and collision reaction cell

中文关键词:  超级微波消解  电感耦合等离子质谱法  蔬菜  元素

英文关键词:super microwave digestion  inductively coupled plasma mass spectrometry  vegetables  elements

中文摘要:

      目的 建立超级微波消解-碰撞反应池电感耦合等离子体质谱法同时测定蔬菜中铅、砷、镉、铬等21种元素的方法。方法 选择超级微波消解法进行样品预处理, 以硝酸为消解液, 运用具有八极杆反应池系统的电感耦合等离子体质谱仪, 以铂锥作为采样锥, 使用He气碰撞模式(5 mL/min), 通过动能歧视和碰撞诱导解离进行干扰的消除。此外, 选择包括低、中、高质量范围的6Li、45Sc、72Ge、103Rh、115In、159Tb、175Lu、209Bi元素作为内标, 使用在线添加内标的方式进行干扰消除, 并在数据分析时采用虚拟内标校正模式。结果 在优化后的实验条件下, 21种元素在一定的质量浓度区间内, 其对应的信号强度与质量浓度呈线性关系。标准曲线线性良好, 相关系数在0.999~1.000之间。方法的检出限在0.005~1.200 mg/kg, 定量限在0.015~3.600 mg/kg。方法通过加标回收测定回收率, 加标回收率在85.2%~119.9%之间。对处理后的蔬菜样品加入低、中、高3种不同浓度的标准, 每份平行测定7次, 测定值的相对标准偏差在1.03%~4.60%之间。结论 通过本研究方法对蔬菜样品中21种元素进行测定, 满足国家标准对各项技术指标参数的要求。该方法检出限低, 选择性好, 结果准确可靠, 为蔬菜样品中多种元素分析测定提供了新的参考方法。

英文摘要:

      Objective To establish a method for the simultaneous determination of 21 kinds of elements including lead, arsenic, cadmium and chromium in vegetables by inductively coupled plasma mass spectrometry with a super microwave digestion-collision reaction cell. Methods Super microwave digestion was selected for sample pretreatment, nitric acid was used as the digestion solution, an inductively coupled plasma mass spectrometer with an octopole reaction cell system was utilized, a platinum cone was used as the sampling cone, and the He gas collision mode (5 mL/min) was used for the elimination of interferences through kinetic energy discrimination and collision-induced dissociation. In addition, elements including 6Li, 45Sc, 72Ge, 103Rh, 115In, 159Tb, 175Lu and 209Bi in the low-, medium-, and high-mass ranges were selected as internal standards, and interference elimination was carried out by using on-line additions of the internal standards, and the virtual internal standard correction mode was used in data analysis. Results Under the optimized experimental conditions, the corresponding signal intensities of the 21 kinds of elements were linearly related to the mass concentrations in a certain mass concentration interval. The standard curves were linear and the correlation coefficients were in the range of 0.999–1.000. The limits of detection of the method were in the range of 0.005–1.200 mg/kg, and the limits of quantitation were in the range of 0.015–3.600 mg/kg. The recoveries of the method were determined by spiked recoveries, and the spiked recoveries were in the range of 85.2%–119.9%. The treated vegetable samples were spiked with three different concentrations of standards, low, medium and high, and each of them was measured in parallel for seven times. The relative standard deviations of the determined values were in the range of 1.03%–4.60%. Conclusion The determination of 21 kinds of elements in vegetable samples by the method of this study meets the requirements of the national standards for each technical index parameter. The method is characterized by low limit of detection, good selectivity, accurate and reliable results, and provides a new reference method for the analysis and determination of various elements in vegetable samples.