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41.
Parvaneh Hajeb Abu B. Fatimah Bakar Jamilah 《International journal of environmental analytical chemistry》2013,93(10):812-820
The study evaluated methylmercury concentrations, the methylmercury to total mercury ratio (%MeHg) and their correlations in ten fish species from different trophic levels. Methylmercury levels in fish studied were in the range of 0.007 to 0.914 µg g?1 wet wt. Muscle tissue of predatory fish contained significantly (p < 0.05) higher content of methylmercury than non-predatory fish. The methylmercury to total mercury ratio ranged from 49.1% to 87.5%, with the highest ratio in predatory fish. This ratio was always higher in muscle tissue compared to the liver tissues, indicating tissue-specific binding and accumulation of methylmercury in the muscle. All the fish species showed strong positive correlation between methylmercury and total mercury levels (R 2> 0.86). Except for long tail tuna and short-bodied mackerel, all fish species showed lower methylmercury levels and estimated weekly intake as compared to the maximum values established by US FDA (of 0.5 µg g?1) and by FAO/WHO (1.5 µg kg?1 bodyweight), respectively. This study showed that the percentage of methylmercury is rather high in fish and fish represents the major source of this toxic mercury form to the local population. 相似文献
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A precise and accurate method has been developed for the determination of methylmercury in biological material using capillary gas chromatography with electron-capture detection. Homogenized fish or mussel samples were digested with acid, spiked with ethylmercury chloride as an internal standard and extracted with toluene. After treatment of the solvent extract with sodium thiosulphate and cupric bromide the alkylmercurials were extracted into benzene as their bromide derivatives and analyzed using an OV-275 coated glass capillary column. The detection limit of the method for methylmercury was 5 g/kg tissue. 相似文献
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Methylmercury as well as mercury (II) were found to be effective inhibitors of the catalytic activity of alcohol dehydrogenase
from baker’s yeast in the reaction of ethanol oxidation by nicotinamide adenine dinucleotide. It was stated that the methylmercury
inhibitory action belonged to the non-competitive type, whereas Hg(II) inhibited the enzyme according to the mixed type. The
inversely proportional dependence of the indicator reaction rate on the concentration of methylmercury allowed to develop
an enzymatic procedure for its determination with a detection limit of 3 nM. The possibility of methylmercury determination
in presence of mercury (II) and mercury (II) determination in presence of methylmercury (concentration ratios CH3Hg+:Hg(II) were 1:1 and 1:10, respectively) was shown. In the first case masking reagents, DEDTC or thiourea, were used to form
stable complexes with Hg(II).
Received February 9, 2001; accepted August 10, 2001; published online June 24, 2002 相似文献
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