ON THE CHEMICAL FORM OF MERCURY IN EDIBLE FISH AND MARINE INVERTEBRATE TISSUE
ON THE CHEMICAL FORM OF MERCURY IN EDIBLE FISH AND MARINE INVERTEBRATE TISSUE
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DOI：
10.1139/f92-113
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发表时间：
1992-05-01
影响因子：
2.4
通讯作者：
BLOOM, NS
中科院分区：
文献类型：
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作者：
BLOOM, NS
采用超净技术对7种淡水鱼、8种咸水鱼和几种海洋无脊椎动物的229个样品中的总汞、一甲基汞(CH3)和二甲基汞((CH3)2HG)进行了检测。总汞的测定采用HNO_3/H_2SO_4/BrCL热消化、SnCl2还原、金净化、冷原子荧光光谱分析等方法。甲基汞的测定采用氢氧化钾/甲醇消解，水相乙基化、低温气相色谱和电感耦合等离子体原子荧光检测。所有样品的总汞和CH3汞浓度从0.011至2.78mU·g·g-1(湿重基，以汞表示)，而没有样品含有可检测到的(CH3)2HG(<；0.001-mU·g·g-1以汞表示)。观测到的总汞比例(以CH3Hg计)从69%到132%不等，五重分析的相对标准偏差约为10%；几乎所有这种变化都可以用总汞和CH3Hg的分析变异性来解释。均匀性差的样品表现出更大的变异性，主要是因为总汞和CH3汞是在不同的等分线上测量的，这些等分线的汞浓度不同，而不是形态。我的结论是，对于所研究的所有物种，几乎所有(95%)存在的汞都是以CH3Hg的形式存在的，过去关于CH3Hg组分显著较低的报道可能受到分析和同质性变异性的影响。
Total mercury, monomethylmercury (CH3Hg), and dimethylmercury ((CH3)2Hg) in edible muscle were examined in 229 samples, representing seven freshwater and eight saltwater fish species and several species of marine invertebrates using ultraclean techniques. Total mercury was determined by hot HNO3/H2SO4/BrCl digestion, SnCl2 reduction, purging onto gold, and analysis by cold vapor atomic fluorescence spectrometry (CVAFS). Methylmercury was determined by KOH/methanol digestion using aqueous phase ethylation, cryogenic gas chromatography, and CVAFS detection. Total mercury and CH3Hg concentrations varied from 0.011 to 2.78-mu-g.g-1 (wet weight basis, as Hg) for all samples, while no sample contained detectable (CH3)2Hg (< 0.001-mu-g.g-1 as Hg). The observed proportion of total mercury (as CH3Hg) ranged from 69 to 1 32%, with a relative standard deviation for quintuplicate analysis of about 10%; nearly all of this variability can be explained by the analytical variability of total mercury and CH3Hg. Poorly homogenized samples showed greater variability, primarily because total mercury and CH3Hg were measured on separate aliquots, which vary in mercury concentration, not speciation. I conclude that for all species studied, virtually all (> 95%) of the mercury present is as CH3Hg and that past reports of substantially lower CH3Hg fractions may have been biased by analytical and homogeneity variability.