电感耦合等离子体质谱法与直接测汞仪法测定食品级润滑油中汞含量的比较

Comparison of determination of total mercury content in food-grade lubricant by inductively coupled plasma mass spectrometry and diret mercury vapourmeter method

中文关键词:  电感耦合等离子体质谱法  直接测汞仪  汞  食品级润滑油

英文关键词:inductively coupled plasma mass spectrometry  direct mercury vapourmeter  mercury  food-grade lubricant

中文摘要:

      目的 比较电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)和直接测汞仪法测定食品级润滑油中汞(Hg)含量的结果。方法 采用微波消解仪对样品进行消解, ICP-MS检测, 内标法定量。另采用直接测汞仪法测定待测样无需消解前处理, 直接进样, 外标法定量。结果 在最优仪器条件下, ICP-MS法测定的Hg在0.5~20 μg/L范围内线性关系良好, 相关系数为0.9998, 方法检出限为0.5 μg/kg。重复性相对标准偏差(relative standard deviation, RSD)为4.15% (n=10), 样品加标回收率为95.21%~104.57% (n=7); 直接测汞仪法测定Hg在5.00~200 μg/L范围内线性关系良好, 相关系数为0.9997, 方法检出限为 0.5 μg/kg。重复性相对标准偏差为3.42% (n=10), 样品加标回收率为94.87%~98.40% (n=7)。结论 2种测定方法准确、灵敏度高, 均能测定食品级润滑油中总汞元素。大量检测可选择微波消解-ICP-MS检测法; 如果少量检测可选择直接测汞仪法。

英文摘要:

      Objective To compare the results of determination of total mercury in food-grade lubricant by inductively coupled plasma mass spectrometry (ICP-MS) and direct mercury vapourmeter method. Methods The samples were digested by microwave digestion apparatus, detected by ICP-MS and quantified by internal standard method. In addition, the samples were determined by direct mercury meter method without digestion pretreatment. The samples were directly injected and quantified by external standard method. Results Under optimal instrument conditions, Hg had good linear relationships in the range of 0.5?20 μg/L by ICP-MS. The correlation coefficient was 0.9998, and the limit of detection was 0.5 μg/kg. The relative standard deviation (RSD) of repeatability was 4.15% (n=10) and the recovery rates were 95.21%?104.57% (n=7). Hg elements showed good linear relationships in the range of 5.00?200 μg/L determined by direct mercury analyzer method. The correlation coefficients were 0.9997, and the limit of detection was 0.5 μg/kg. The RSD of repeatability of this method was 3.42% (n=10), and the recovery rates were 94.87%?98.40% (n=7). Conclusion Both of 2 methods are accurate and sensitive, both of which can determine the total mercury in food grade lubricating oil. The microwave digestion-ICP-MS detection method can be selected for a large number of detections, and the direct mercury measurement method can be selected for a small amount of detection.