电感耦合等离子体串联质谱与电感耦合等离子体质谱法测定蜂蜜中微量硒的对比研究

The Comparison of ICP-MS/MS and ICP-MS for Determination of Selenium in Honey

利用微波消解-电感耦合等离子体串联质谱(ICP-MS/MS)技术,建立了一种快速测定蜂蜜中微量Se的方法。在MS/MS模式下设置Q1为(m/z)78、80、82,使用O2作为池气体,设定流速为0.40mL/min,Se^+与O_2反应后生成SeO+,再将Q2分别设置为(m/z)94、96、98,然后进行测定。研究表明:Q1=78/Q2=94的质量对在0.041~5μg/L范围内线性关系良好(R=0.9999),检出限为0.013μg/L,样品加标回收率为89.3%~106.7%,相对标准偏差(RSD)为1.1%~3.6%。另外,比较MS/MS模式和MS模式(Q1作为离子导杆)下消除Ca、K元素产生的多原子离子干扰的差异性以及对Se含量测定的影响。与ICP-MS相比,ICP-MS/MS下采用两级质谱进行质量筛选,并结合O2反应,通过质量转移法能获得良好的灵敏度、更低的检测限、更低的背景等效浓度(BEC)和更准确的检测结果,为类似物质的分析提供了参考。

A rapid method for the determination of trace selenium（Se）in honey was established by microwave digestion-inductively coupled plasma tandem mass spectrometry（ICP-MS/MS）.Oxygen was selected as the cell gas in MS/MS mode,and the flow rate was set at 0.40 mL/min.Q1 of three main kinds of Se isotopes was set to（m/z）78,80 and 82,respectively.When Se reacted with O2 to form SeO~＋,Q2 was set to（m/z）94,96 and 98,respectively.The results showed that analytical calibration curves ranging from 0.041μg/L to 5μg/L for selecting the set of mass pairs of Q1=78/Q2=94 was obtained with good linear correlation coefficient（0.9999）in MS/MS mode.The limits of detection（LOD）was 0.013μg/L.The recoveries for Se at two spiked levels were89.3%-106.7% with relative standard deviations ranging from 1.1% to 3.6%.Furthermore,when the operation condition of MS mode（Q1 as an ion guide rod）was set on ICP-MS/MS mode,the influence on Se content and the difference of eliminating polyatomic interference from Ca and K elements in honey were compared between the two modes.Compared with ICP-MS,the proposed O2 mass shift method of ICP-MS/MS can obtain good sensitivity,lower detection limit,lower background equivalent concentration（BEC）and more accurate result.