摘要
本文将原子荧光光谱检测技术与吹扫捕集/气相色谱检测技术联用,结合优化的碱性法消解前处理技术,建立了碱性法消解-吹扫捕集/气相色谱-原子荧光光谱(PT-GC-AFS)联用技术测定土壤和沉积物中烷基汞含量的方法,能够在一次分析中同时获得样品中甲基汞和乙基汞的含量.本文分别用酸性法和碱性法处理了沉积物标准样品ERM-CC580、沉积物实际样品和土壤实际样品,重点比较了本方法提出的碱性法消解和使用率较高的酸性法消解两种前处理方式.采用本方法处理实际样品进行了色谱分离研究,对低浓度的实际土壤样品进行了检出限实验,用3种不同浓度的沉积物和3种不同浓度的土壤样品验证了精密度,对沉积物标准参考物质ERM-CC580进行了测定,并用两种实际土壤样品和两种实际沉积物样品进行了加标回收率试验.实验表明,碱性法消解精密度和准确度优于酸性法消解,且步骤少、耗时短,使用的试剂种类少、毒性小,方法稳定性高、可操作性强,适用于分析测试实验室大量土壤/沉积物样品的烷基汞测定.采用碱性法消解土壤/沉积物样品,目标物实现完全分离,甲基汞、乙基汞的线性相关系数分别为0.9999、1.0000,最低检出限分别为0.02μg·kg-1、0.10μg·kg-1(取样量为0.50 g),样品分析甲基汞、乙基汞的RSD范围分别为1.0%—4.7%、2.5%—6.0%,加标回收率范围分别为85.1%—109%、90.3%—96.3%.
A method for the determination of alkyl mercury in soils and sediments by purge and trap/gas chromatography coupled with atomic fluorescence spectrometry(PT-GC-AFS) was established by using alkaline digestion. Atomic fluorescence spectrometry was combined with purge and trap/gas chromatography, and the optimized alkaline digestion pretreatment was used. The simultaneous determination of methyl mercury and ethyl mercury in soils and sediments was achieved. In this paper, the standard sediment sample ERM-CC580, the sediment samples and the soil samples were treated by acidic digestion and alkaline digestion respectively to compare the acidic digestion and the alkaline digestion. The actual samples were treated by alkaline digestion for chromatographic separation test. The method detection limit experiment was carried out with the soil samples of low concentration. The precision was tested with three different concentrations of sediments and soils. The standard sediment sample ERM-CC580 was determined. Two kinds of soil samples and sediment samples were used to test the recovery. The experimental results showed that the alkaline digestion demonstrated better precision and accuracy. Moreover, the alkaline digestion had the advantages of less steps, less time, less reagents, less toxicity, better stability and easier to operate. This method was suitable for the determination of alkyl mercury in laboratory with large sample size. Under the optimal experimental conditions, the alkyl mercury could be completely separated. The linear correlation coefficients of methyl mercury and ethyl mercury were 0.9999 and 1.0000, respectively. The method detection limit(MDL) were 0.02 μg·kg-1 and 0.10 μg·kg-1(sample quantity 0.50 g), respectively. The relative standard deviation(RSD) were 1.0%—4.7% and 2.5%—6.0%, respectively. The recoveries of the method respectively were 85.1%—109% and 90.3%—96.3%.
作者
龙雯琪
朱日龙
林海兰
魏凤
童若辉
刘丽
张霖琳
LONG Wenqi;ZHU Rilong;LIN Hailan;WEI Feng;TONG Ruohui;LIU Li;ZHANG Linlin(Hunan Ecological and Environmental Monitoring Center,State Environmental Protection Key Laboratory of Monitoring for Heavy Metal Pollutants,Changsha,410019,China;China National Environmental Monitoring Centre,State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring,Beijing,100012,China;College of Chemistry and Chemical Engineering,Hunan University,Changsha,410082,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第7期1934-1940,共7页
Environmental Chemistry
基金
国家环保公益性行业科研专项(201309050)
首都科技条件平台科研项目(Z181100009518003)资助
关键词
碱性法消解
吹扫捕集/气相色谱
原子荧光光度法
烷基汞
alkaline digestion
purge and trap/gas chromatography
atomic fluorescence spectrometry
alkyl mercury
