小浪底水库鱼体汞的污染现状

Mercury contents in the muscle tissue of fish species in Xiaolangdi Reservoir

采用混酸消解-冷原子荧光(CVAFS)方法和氢氧化钾甲醇溶液消解-水相乙基化衍生-气相色谱-冷原子荧光方法(GC-CVAFS)分别测定了小浪底水库中常见的6种鱼类肌肉组织中的总汞和甲基汞含量.结果表明,小浪底水库鱼体总汞平均含量为(99.2±42.6)ng·g-1,变化范围为31.6—210 ng·g-1.甲基汞的平均含量为(83.6±42.1)ng·g-1,变化范围为20.0—194 ng·g-1.甲基汞占总汞比例平均值为(82.5±9.3)%.鱼体汞含量表现为肉食性鱼、杂食性鱼高于植食性鱼的趋势.只有鳙鱼体内总汞、甲基汞含量与其体长体重呈显著的正相关关系,其他几种鱼总汞、甲基汞含量与其体长体重的相关性不显著.本研究鱼肌肉样品中甲基汞含量均低于国家相关标准,但与国内相关研究相比,小浪底水库鱼肉组织中汞含量处于较高水平.敏感人群应该限制小浪底水库中鳙鱼、黄颡鱼、鲤鱼这些甲基汞含量较高的水产品的食用量和食用频率.

Six fish species were sampled from Xiaolangdi Reservoir, a newly built reservoir located in Henan Province. Total mercury （THg） and methylmercury （MeHg） contents in the fish muscle tissues were determined using acid digestion-purge and trap-cold vapor atomic fluorescence spectrometry （CVAFS） and KOH/methanol digestion-aqueous phase ethylation-purge and trap-gas chromatography-CVAFS methods, respectively. THg in the fish muscle tissues varied from 31.6 ng.g-1 to 210 rig-g-1（average （99.2 ＋ 42.6） ng.g-1）, and MeHg varied from 20.0 ng·g-1 to 194 ng-g-1（average （83.6 ＋42. 1） ng.g-1）. Piscivores and omnivores had significantly correlated with fish higher Hg contents than herbivores. size, however, this correlation was not Mercury contents in bighead carp significant for all the other fish species （P 〉 0. 05）. Mercury contents in the muscle tissue of fish samples met the requirement of Chinese National Standard-Maximum Levels of Contaminants in Foods（GB2762--2012）. However, they were relatively high in comparison to previously studies in other geographic regions. Thus it was suggested that sensitive populations should pay attention to the consumption amount of fish species including bighead, carp and yellow-head catfish.