Shi Jian-Bo, Liang Li-Na, Jiang Gui-Bin
Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, People's Republic of China.
J AOAC Int. 2005 Mar-Apr;88(2):665-9.
A comprehensive method for simultaneous determination of methylmercury (MeHg) and ethylmercury (EtHg) in rice by capillary gas chromatography (GC) coupled on-line with atomic fluorescence spectrometry was developed. The experimental conditions, including the pyrolyzer temperature and flow rates of the make-up gas and sheath gas, were optimized in detail. The absolute detection limits (3sigma) were 0.005 ng as Hg for both MeHg and EtHg. The relative standard deviation values (n=5) for 10 ng Hg/mL of MeHg and EtHg were 2.5 and 1.3%, respectively. The method was evaluated by analyzing 2 certified reference materials (DORM-2 and GBW08508), and the determined values of MeHg and total mercury concentrations were in good agreement with the certified values. In addition, the recoveries of MeHg and EtHg spiked into a rice sample collected from Jiangsu province in China were 86 and 77%, respectively. The proposed method was applied to analysis of MeHg and EtHg in 25 rice samples cultivated in 15 provinces of China. In all samples, MeHg was detectable and no EtHg was found. The MeHg contents in rice samples ranged from 1.9 to 10.5 ng/g, accounting for 7-44% of the total mercury measured.
建立了一种采用毛细管气相色谱（GC）与原子荧光光谱在线联用同时测定大米中甲基汞（MeHg）和乙基汞（EtHg）的综合方法。详细优化了包括裂解器温度、补充气和鞘气流量在内的实验条件。MeHg和EtHg的绝对检测限（3σ）均为0.005 ng汞。10 ng Hg/mL的MeHg和EtHg的相对标准偏差值（n = 5）分别为2.5%和1.3%。通过分析2种标准参考物质（DORM - 2和GBW08508）对该方法进行了评估，MeHg和总汞浓度的测定值与认证值高度吻合。此外，添加到从中国江苏省采集的大米样品中的MeHg和EtHg的回收率分别为86%和77%。所提出的方法应用于对中国15个省份种植的25个大米样品中MeHg和EtHg的分析。在所有样品中，均检测到MeHg，未发现EtHg。大米样品中MeHg含量在1.9至10.5 ng/g之间，占所测总汞的7 - 44%。
