摘要
目的比较超级微波消解-电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)和测汞仪法测定茶叶中总汞(Hg)的含量情况。方法第一法采用超级微波进行消解, ICP-MS检测,外标法定量。第二法为测汞仪法,无需消解前处理,采用直接进样方式,外标法定量。结果在最优仪器条件下,超级微波消解-ICP-MS法测定的Hg在0~2 ng/mL范围内线性关系良好,相关系数为1.0000,方法检出限为1μg/kg。方法成功用于40个茶叶样品(包括红茶、绿茶、白茶、黄茶、花茶、乌龙茶、袋泡茶、紧压茶和黑茶)中Hg的测定,样品加标回收率在95.5%~106.4%之间,相对标准偏差(relative standard deviation,RSD)均不超过3.86%。测汞仪法测定Hg在0~20 ng范围内线性关系良好,相关系数为0.9997,方法检出限为0.05μg/kg。测汞仪法同样用于40个茶叶中Hg的测定,样品加标回收率在93.2%~103.7%之间,RSD不超过6.65%。结论两种测定方法简便快速、准确、灵敏度高,均能为快速测定茶叶中总汞元素提供有效的分析方法。测汞仪法相对波动较大,但是能满足检验检测需求。
Objective To compare the determination of total mercury in tea by ultra microwave digestion-inductively coupled plasma mass spectrometry(ICP-MS) and mercury vapourmeter method.Methods In the first method, the sample was digested by ultra microwave, detected by ICP-MS and quantified by external standard method.The second method was mercury vapourmeter method, which did not need digestion pretreatment and injected the sample directly, with quantification by external standard method.Results Under optimal instrument conditions, Hg had good linear relationships in the range of 0~2 ng/mL by ultra microwave digestion-inductively coupled plasma mass spectrometry with the correlation coefficient was 1.0000, and the limit of detection was 1 μg/kg.This method was successfully applied to the determination of Hg in 40 tea samples(including black tea, green tea, white tea, yellow tea, flower tea, oolong tea, teabag, squeeze tea and dark tea), and the recoveries were between 95.5%-106.4% with the relative standard deviations no more than 3.86%.Hg elements showed good linear relationships in the range of 0-20 ng by mercury vapourmeter method with the correlation coefficients was0.9997, and the limit of detection was 0.05 μg/kg.This method was also used for the determination of Hg in the same40 tea samples, and the recoveries were 93.2%-103.7% with RSD less than 6.65%.Conclusion This two methods are simple, rapid, accurate and sensitive, which can provide effective analytical methods for the rapid determination of total mercury in tea.Mercury vapourmete method fluctuates greatly, but it can meet the requirements of inspection and detection.
作者
李琼
林毅韵
李樑
霍霈霖
何霜
LI Qiong;LIN Yi-Yun;LI Liang;HUO Pei-Lin;HE Shuang(National Centre for Quality Inspection of Processed Food(Guangdong),Guangzhou Inspection and Certification Group Co.,Ltd.,Guangzhou 510000,China)
出处
《食品安全质量检测学报》
CAS
2019年第13期4261-4265,共5页
Journal of Food Safety and Quality
关键词
超级微波
电感耦合等离子体质谱法
测汞仪
汞
茶叶
ultra microwave
inductively coupled plasma mass spectrometry
mercury vapourmeter
mercury
tea
