溶解有机质（dissoved organic matter, DOM）的荧光组分可有效调控锑（Sb）在地下水中的运移。然而，其分子组成对Sb环境行为的影响还不明晰。为此，采集了湖南锡矿山锑矿区10组高低Sb地下水样品，通过对比分析DOM分子组成的差异，揭示了DOM分子组成对高Sb地下水形成的调控机制。研究结果表明高低锑地下水中DOM的含量分别为2.24 ~ 10.45 mg/L（均值5.19 mg/L）和3.22 ~ 3.23 mg/L（均值3.23 mg/L）。相比低Sb地下水，高Sb地下水拥有较高的高度不饱和烃类和多酚，较低浓度的脂肪类化合物、饱和烃类和多环芳烃。高O/C > 0.50和低H/C < 1.20的高度不饱和烃类和多酚与Sb浓度密切正相关。大分子芳香族DOM可通过与Sb（V）竞争吸附沉积物界面的吸附点位，与Fe和Sb（V）形成DOM-Fe-（V）络合物，以及增强Fe（Ⅱ）和Sb（Ⅲ）共氧化速率来促进高Sb地下水的形成。

The fluorescence components of dissolved organic matter (DOM) is a crucial controlling factor in mobilizing antimony in groundwater. However, the effect of molecular composition of DOM on Sb behaviors is still unclear. A total of 10 samples were collected from high-and low-Sb groundwater in the Xikuangshan mine to compare the molecular composition of DOM and to determine the roles of DOM in Sb mobility. The results show that the DOM content in high-and low-Sb groundwater was 2.24 ~ 10.45 mg/L(mean 5.19 mg/L) and 3.22 ~ 3.23 mg/L(mean 3.23 mg/L), respectively. Compared with low-Sb groundwater, high-Sb groundwater has more highly unsaturated and phenolic compounds and polyphenols, and lower aliphatic compounds, saturated compounds and polycyclic aromatics. Sb positively associated with high O/C ratio (O/C > 0.5) and low H/C ratio molecules (H/C < 1.2), which mainly grouped as highly unsaturated and phenolic compounds and polyphenols. Complexing agents with Fe and Sb(V), competitive adsorption with Sb(V), and accelerating the rate of Sb(Ⅲ) and Fe(Ⅱ) co-oxidation were considered as the formation mechanisms for DOM on Sb migration at a molecular level.