高效液相色谱-原子荧光光谱法应用于不同营养级鱼肌中汞的形态分析

汞是环境中最具威胁的元素之一，各形态汞的毒性不同，并且会随食物链的传递积累. 因此，同时检测鱼肌中不同形态的汞含量，并分析其在不同生境及营养级的差异性具有相当重要的研究价值. 通过高效液相色谱-原子荧光光谱联用法改变流动相中甲醇的浓度、光电倍增管负高压、空心阴极灯电流、还原剂及载流的浓度等条件，优化了不同汞形态组分的分离程度和响应值. 在优化的试验条件下，将鱼肌样品经离心、过柱、洗脱等步骤处理后，由液相色谱分离，最终通过原子荧光法检测提取溶液中3种汞形态. 结果表明，二价汞、甲基汞、乙基汞在0.2~10.0 μg/L质量浓度范围内线性关系良好，相关系数均大于0.999 9，方法检出限在0.39~0.82 μg/kg之间，平行样品相对标准偏差(RSD)均小于4.0%. 方法前处理简单，准确度高，适用于鱼肉中汞的形态分析. 方法应用于不同生境、不同营养级的鱼肌样品检测，可观察到不同营养级样品结果明显的差异性及同类样品间的相关性.

Application of High Performance Liquid Chromatography-Atomic Fluorescence Spectrometry to Speciation Analysis of Mercury in Fish Muscle of Trophic Levels

Mercury is one of the most threatening elements in the environment. The toxicity of different forms of mercury is different. Among them, methyl mercury is the most toxic one, which is harmful to human cardiovascular and cerebrovascular system, nervous system and so on. At the same time, methyl mercury will accumulate with the transmission of food chain. Fish is a common human food. Therefore, it is necessary to detect the mercury content of different forms in fish muscle simultaneously. It is of great research value to analyze the differences in different habitats and trophic levels. By changing the concentration of methanol in the mobile phase, negative high voltage of photomultiplier tube, current of hollow cathode lamp, reducing agent and carrier current, the separation degree and response value of different mercury speciation components were optimized. After optimized the experimental conditions, the fish muscle samples were treated by centrifugation, passing through the column, elution and other steps. Then the extract was added and centrifuged twice. After adjusting the pH, the extract was purified in a C18 column, and then eluted twice by the mobile phase. The fish samples were separated by liquid chromatography, and the three mercury forms in the extraction solution were detected by atomic fluorescence spectrometry. The results showed that the linear range of divalent mercury, methyl mercury and ethyl mercury was 0.2~10.0 μg/L respectively, the correlation coefficients were more than 0.999 9, the detection limit was 0.39~0.82 μg/kg, and the relative standard deviation (RSD) of parallel samples was less than 4.0%. The method is accurate, efficient, and is suitable for the speciation analysis of mercury in fish. If the method is applied to fish muscle samples from different habitats and different trophic levels, obvious differences of the results of different trophic levels and the correlation between the similar samples could be observed.