增敏剂改进超级微波消解-电感耦合等离子体质谱(ICP-MS)法测定食品中硒元素

合适比例增敏剂会对超级微波消解-电感耦合等离子体质谱法(ICP-MS)测定食品中硒元素含量具有一定的优化效果。本文采用超级微波消解仪对1.0 g食品样品进行全消解，采用碰撞池模式规避质谱干扰，内标校正非质谱干扰，选择甲醇、乙醇、乙酸、异丙醇、丙三醇作为增敏剂，并调整测试过程中的添加比例，用电感耦合等离子体质谱法测定。结果表明：2%异丙醇存在时硒元素各同位素响应值最高，其中78Se具有低至0.0003 mg·kg-1的方法检出限；用以上方法对食品标准物质（GSB-8、GSB-9、GSB-24、GSB-30）及实际样品进行分析，标准物质测定值均在其认定值及不确定度范围内，相对误差小于-5.4%；实际样品测定值的相对标准偏差（n=7，RSD）为0.3~1.7%，加标回收率为99.2~105%。本方法操作简便，精密度好，准确度高，可以作为各类食品样品中硒含量测试方法。

Determining of Selenium in Food by Sensitizer Improved Supermicrowave Digestion-inductively Coupled Plasma Mass Spectrometry

A sensitizer with a suitable proportion will have a certain optimization effect on the determination of selenium content in food by super microwave digestion-inductively coupled plasma mass spectrometry. In this paper, the super microwave digestion instrument was used to fully digest 1.0 g food samples, the collision cell mode was used to avoid mass spectrometry interference, the internal standard was corrected for non-mass spectral interference, methanol, ethanol, acetic acid, isopropanol, and glycerol were selected as sensitizers, the addition ratio during the test process was adjusted, as well as inductively coupled plasma mass spectrometry was used. The results showed that the response value of selenium was the highest in the presence of 2% isopropanol, and the method limit of detection was 0.0003 mg·kg-1. The above methods were used to analyze food standard substances (GSB-8, GSB-9, GSB-24, GSB-30) and actual samples; the measured values of the food standard substances were within the range of their identified values and uncertainties, and the relative error was less than -5,4%. The relative standard deviation (n=7, RSD) of the actual sample measurement value was 0.3~1.7%, and the recovery rate of spiking was 99.2~105%. The method is simple, precise and accurate, and can be used for the determination of selenium content in various food samples.