In this study, the hydrolysis of amisulbrom in buffer solutions and natural water samples were investigated. Effects of pH and temperature were tested in buffer solutions. Amisulbrom was stable in acidic and neutral aqueous solutions at 25°C, while quickly hydrolyzed with a half-life of 4.5 days (25°C) at pH 9.0. The kinetics rate equation was determined as k = 1.0234 × 10¹⁰ exp (−61.3760/R·T) (R² = 0.9642) for hydrolysis of amisulbrom at pH 9.0. The pH, ionic strength, and solubility were important factors influencing the hydrolysis of amisulbrom in natural water samples. Furthermore, three hydrolysis products were separated and identified in buffer solution (pH 9.0) and natural water samples. A tentative transformation mechanism of amisulbrom was proposed to rationalize the formation of HPs (hydrolysis products) based on their structural identification, DFT (density functional theory), and hydrolysis profiles. Toxicity prediction using the quantitative structure–activity relationship model revealed that the HP-I, and HP-II were more toxic than the parent amisulbrom. This investigation was the first to evaluate the behavior of amisulbrom hydrolysis in aquatic systems.

中文翻译：

---

缓冲溶液和天然水样品中氨磺胺的水解：动力学和产物鉴定。

在这项研究中，研究了缓冲液和天然水样品中amululbrom的水解。在缓冲溶液中测试了pH和温度的影响。Amisulbrom在25°C的酸性和中性水溶液中稳定，而在pH 9.0时，其半衰期为4.5天（25°C），可快速水解。动力学速率方程确定为k  = 1.0234×10 ¹⁰ exp（-61.3760 / R·T）（R ² = 0.9642）在pH 9.0时水解羊膜。pH，离子强度和溶解度是影响天然水样品中amululbrom水解的重要因素。此外，在缓冲溶液（pH 9.0）和天然水样品中分离并鉴定了三种水解产物。根据其结构鉴定，DFT（密度泛函理论）和水解曲线，提出了一种变形性的变形蛋白机制来合理化HPs（水解产物）的形成。使用定量结构-活性关系模型进行的毒性预测表明，HP-1和HP-2的毒性要比母体amululbrom更大。这项研究是第一个评估水生系统中氨溴铵水解行为的研究。