采用改进的 Tessier 法及王水消解法，以冷原子荧光技术对海南乐东海域10个浅表沉积物中总汞及各形态汞进行了测定。系统考察了高锰酸钾对提取液中汞的氧化条件。样品中各形态汞的检出限范围为0.0003～0.0027μg/g，总汞检出限为0.0021μg/g，各形态汞之和与总汞的百分比范围为92.2%～115%。2个海洋沉积物标准物质（GBW07314，GBW07334）总汞及各形态之和的测量值均与参考值吻合。除离子交换态和碳酸盐结合态因含量太低而导致 RSD 大于10%以外，其他3个态的 RSD 范围均在2.7%～6.7%之间。9个样品总汞含量均未超过我国海洋沉积物质量第1类标准。各形态汞占总汞的平均百分比顺序为：残渣态>铁锰氧化态>有机结合态>碳酸盐结合态>离子交换态，前三个态之和占到94.25%，后两个态仅占5.75%。总汞与铁锰氧化态和残渣态之间均具有显著相关性，后两种形态控制了总汞在不同海水深度下的走势。%Total mercury and mercury species in surface sediments from Hainan Ledong offshore were determined by CV-AFS after aqua regia digestion and extraction with improved Tessier method. The influence of KMnO4 on oxidation of mercury in extraction process was systematically investigated. The results show that the detection limits of mercury species are in the range of 0.000 3 ~ 0.002 7 μg/g and total mercury of 0.002 1 μg/g. The percentages of the sum (of Hg species ) of total Hg are in the range of 92.2%~115%. The measured values (total and sum of species) of mercury in marine reference materials are in good agreement with the recommended values. The RSDs of exchangeable Hg and Hg bound to carbonates are more than 10% due to their lower concentrations, the RSDs of the other three Hg species are in the range of 2.7% ~ 6.7%. The contents of total Hg in nine of the ten samples don’t exceed the national qualityⅠstandard for marine sediment. The average percentages of individual Hg species of total Hg follows: residual Hg > Hg bound to Fe-Mn oxides > Hg bound to organic matter > Hg bound to carbonate > ion exchangeable Hg, the sum of the first three species are 94.25% and the last two species are 5.75%. There are significant correlations between total Hg and Hg bound to Fe - Mn oxide & residual Hg, the last two species control the trend of total mercury in seawater at different depths.
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