改进了 Tessier 顺序提取技术，系统优化了分析测试条件，以氢化物发生-原子荧光法同时测定了海洋浅表沉积物中砷锑总量及其各形态量。结果表明，沸水浴蒸发浓缩可有效消除提取液中醋酸、H2O2的影响；砷锑总量及各形态的检出限均远低于样品中相应组分的含量；海洋标准物质 GBW07316中总砷测定值与参考值、总锑测定值及各形态锑之和均与参考值吻合；砷锑各形态之和与其总量的百分比范围分别为84.08%~103.90%及83.62%~103.90%；样品中总砷及各形态砷的 RSD（n=3）为1.19%~7.27%，锑（除离子交换态）为0.80%~5.76%。砷锑的残渣态最高而离子交换态最低，表明两元素在所处海洋环境中生物活性较低。样品中总砷浓度（4.84~12.05μg/g）明显高于总锑（0.34~1.07μg/g）；总砷、总锑随海水深度的变化趋势主要受控于残渣态，两组变量呈显著正相关，且分别在49、81 m 处达到最大；而离子交换态、碳酸盐结合态和有机结合态分别在19、22和45 m 以上及以下时，均呈现相似和相反的走势，砷锑的这些分布特征可能与其再活化能力、迁移转化行为及水中氧化还原条件有关。%Total and species concentration of arsenic and antimony in surface marine sediments were determined simultaneously by HG-AFS after extraction with improved Tessier method under optimized analysis conditions, respectively. The results show that the influence of acetic acid and H2O2 in the extract can be efficiently eliminated by evaporation and concentration in a boiling water bath. Detection limits of total and species of two elements in selected samples are much lower than the contents of corresponding components. The measured values (total and/or sum of species ) of arsenic and antimony in marine reference materials are in good agreement with recommended values. The percentage ranges of ratios of sum to total concentrations for arsenic and antimony are 84.08%~ 103.9% and 83.62%~103.9%, respectively. The RSDs (n = 3) are 1.19%~7.27% for total arsenic and its species, and 0.80%~5.76% for those of antimony(except the ion – exchangeable). There are the highest contents in residual arsenic & antimony and the lowest in ion-exchangeable fraction, indicating that two elements have lower bioavailability in surrounding environments. The content of total arsenic in the samples is significantly higher than that of total antimony, both of which are lower than the national quality standards for marine sediment and soil, respectively. The trends of total arsenic and antimony in sediments with depth are mainly controlled by residual forms, and there are significantly positive correlation between two sets of variables, and the maximum values are present at the depths of 49,81 m, respectively. The total arsenic and antimony are positively correlated with carbonate bound state and Fe-Mn oxide state, respectively. When depths are above and below 19 , 22 and 45 m, all fractions of exchangeable, bound to carbonates and bound to organic matter have similar and opposite trends, respectively, suggesting that the distribution, reactivation and transportation-transformation of arsenic and antimony are related to redox conditions in waters.
展开▼
