Ruiz-de-Cenzano Manuela, Rochina-Marco Arancha, Cervera M Luisa, de la Guardia Miguel
Department of Analytical Chemistry, University of Valencia, 50th Dr. Moliner St., E-46100 Burjassot, Valencia, Spain.
Ecotoxicol Environ Saf. 2014 Sep;107:90-6. doi: 10.1016/j.ecoenv.2014.05.015. Epub 2014 Jun 11.
Sample thermal decomposition followed by mercury amalgamation and atomic absorption has been employed for the determination of methylmercury (MeHg) in fish. The method involves HBr leaching of MeHg, extraction into toluene, and back-extraction into an aqueous l-cysteine solution. Preliminary studies were focused on the extraction efficiency, losses, contaminations, and species interconversion prevention. The limit of detection was 0.018µgg(-1) (dry weight). The intraday precision for three replicate analysis at a concentration of 4.2µgg(-1) (dry weight) was 3.5 percent, similar to the interday precision according to analysis of variance (ANOVA). The accuracy was guaranteed by the use of fortified samples involving 83-105 percent recoveries, and certified reference materials TORT-2 (lobster hepatopancreas) and DORM-3 (dogfish liver), providing 107 and 98 percent recovery of certified values. The greenness of the method was also evaluated with the analytical eco-scale being obtained a final score of 73 points which means an acceptable green analysis. The method was applied to fifty-seven market samples of different fish acquired from local markets in several sampling campaigns. The content of MeHg found varied between 0.0311 and 1.24µgg(-1) (wet weight), with values that involve 33-129 percent of the total mercury content. Some considerations about food safety were also done taking into account data about Spanish fish consume and Tolerable Weekly Intake (TWI) established for MeHg.
采用样品热分解，随后进行汞齐化和原子吸收法来测定鱼类中的甲基汞（MeHg）。该方法包括用氢溴酸浸出甲基汞，萃取到甲苯中，然后反萃取到l-半胱氨酸水溶液中。初步研究集中在萃取效率、损失、污染以及防止物种转化方面。检测限为0.018µg g⁻¹（干重）。在浓度为4.2µg g⁻¹（干重）时进行三次重复分析的日内精密度为3.5%，与根据方差分析（ANOVA）得到的日间精密度相似。通过使用加标样品保证了准确性，回收率为83 - 105%，以及有证标准物质TORT - 2（龙虾肝胰腺）和DORM - 3（角鲨肝），其认证值的回收率分别为107%和98%。还使用分析生态尺度对该方法的绿色度进行了评估，最终得分为73分，这意味着是可接受的绿色分析。该方法应用于在几次采样活动中从当地市场采集的57个不同鱼类的市场样品。所发现的甲基汞含量在0.0311至1.24µg g⁻¹（湿重）之间，其值占总汞含量的33 - 129%。还考虑了一些关于食品安全的因素，同时考虑了西班牙鱼类消费数据以及为甲基汞确定的每周可耐受摄入量（TWI）。
