超声萃取-冷蒸气-原子荧光光谱法测定沉积物和土壤样品中甲基汞  

CV-AFS Determination of Methyl Mercury in Sediment and Soil Samples with Ultrasonic Extraction

作　　者：张少庆[1] 王起超[2] 崔俊涛[1] 孙晓静[2,3] 郑冬梅[2,3] 

机构地区：[1]吉林农业大学,长春130118 [2]中国科学院东北地理与农业生态研究所,长春130012 [3]中国科学院研究生院,北京100049

出　　处：《理化检验（化学分册）》2009年第11期1273-1275,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-437)

摘　　要：样品中甲基汞用6 mol·L^(-1)盐酸超声提取2 h,离心分离后,上层清液用二氯甲烷萃取。取出有机相,加适量去离子水,于60℃吹氮赶去二氯甲烷,甲基汞保留在水相中。水溶液用9 mol·L^(-1)硫酸酸化后,加入溴化钾和溴酸钾混合溶液将甲基汞转化为无机汞离子,并用冷蒸气-原子荧光光谱法测定其含量。方法的检出限(3S/N)为0.1 pg·g^(-1),所提出的方法用于土壤及沉积物样品中甲基汞的测定,测定结果的相对标准偏差(n=6)均小于5%。用标准加入法测定了方法的回收率,结果达93.6%。Methyl mercury in the sample was extracted ultrasonically with 6 mol·L^-1 HCl for 2 h. After centrifugation, the supernatant extract was extracted with dichloromethane. The organic phase was taken and deionized water was added. Dichloromethane was expelled by evaporation with N2-blowing at 60 ℃ and methyl mercury was retained in the water phase. The water solution was acidified with 9 mol·L^-1 H2SO4 and treated with mixed solution of KBrOs and KBr to transform the methyl mercury into inorganic mercury ion, which was determined by CV-AFS. Detection limit （3S/N） of the method found was 0. 1 pg · g^-1. The proposed method was used in determination of methyl mercury in samples of soil and sediment, giving values of RSD＇s （n=6） less than 5%. Average recovery found by standard addition method attained to a value of 93. 6%.

关 键 词：冷蒸气-原子荧光光谱法 超声提取 沉积物 土壤 甲基汞 

分 类 号：O657.31[理学—分析化学]