高效液相色谱-氢化物发生-原子荧光光谱联用技术测定水中烷基汞

摘要

A method for the determination of Mercury species in both surface water and waste water was established by highrnperformance liquid chromatography ( HPLC ) -hydride generation ( HG) -atomic fluorescence spectrophotometry ( AFS). Samplernwas extracted by dichloromethane, subsequently back-extracted by mixed extractant containing cysteine and ammonium acetaternbefore HPLC-HG-AFS detection. Under the optimized conditions, both methyl mercury and ethyl mercury responded linearly inrnthe concentration of 1-50μg/L. The recoveries for both standard samples and actual samples were 80%-110%. The relativernstandard deviations for the determination of methyl and ethylmercury with the concentration of 1μg/L were 5. 2% and 3. 9% ,rnrespectively. The detection limits for them were 0.4 ng/L and 0.7 ng/L, respectively with the American EPA methord. Thernproposed method is of good accuracy, high repeatability, precision, less interferences from impurities and low cost, which isrnbenefit for expanding and applying in the common laboratory.%建立了高效液相色谱(HPLC)-氢化物发生(HG)-原子荧光光谱(AFS)联用技术分析地表水及废水中甲基汞和乙基汞的方法.样品经二氯甲烷萃取,再以半胱氨酸+乙酸铵溶液反萃取富集,并进入高效液相色谱分离,经形态分析预处理装置后,借助原子荧光光谱法检测.在优化分离条件下,甲基汞和乙基汞在1 ～ 50 μg/L范围内呈现良好的线性关系,对于标准水样、地表水和废水实际水样,加标平均回收率均为80％ ～ 110％.平行进样7次1μg/L的汞混合标准溶液,甲基汞和乙基汞的色谱峰面积的相对标准偏差分别为5.2％和3.9％,检出限则分别为0.4 ng/L和0.7 ng/L.该检测方法前处理简单、回收率稳定、灵敏度和准确度高、检出限低、杂质干扰少、监测费用低,便于在普通实验室推广和应用.