新鱼腥草素钠水溶液的降解动力学研究

Degradation Kinetics of Sodium Lauroyl-α-hydroxyethyl Sulfonate in Aqueous Solution

采用HPLC法研究了新鱼腥草素钠在不同pH缓冲液中的降解动力学特征。动力学拟合线性分析表明,新鱼腥草素钠在pH4.0～11.0范围内的降解反应均符合二级动力学规律,降解速率K受pH影响显著,pH-K曲线呈钟罩形;在pH7.0～8.0的溶液中降解速率最快,在pH4.0及pH11.0的溶液中新鱼腥草素钠相对较稳定。提示新鱼腥草素钠在水溶液中的降解并非简单的酸碱催化反应,在特定的pH范围内,存在控速的反应步骤。

The HPLC method was used to investigate the degradation kinetic characters of sodium lauroyl-α- hydroxyethyl sulfonate （sodium neohouttuynin） at different pH buffer. With comparative regression analysis of linear fit, the degradation met the second-order kinetics in pH 4.0 - 11.0 phosphate buffer. It showed that the degradation rate （K） was influenced significantly by pH. The pH-K curve was bell-like. The degradation rate was fast at pH 7.0 - 8.0 and sodium lauroyl-α-hydroxyethyl sulfonate was relatively stable in the solution at pH 4.0 or pH 11.0. Therefore, the degradation was not simply an acid-base catalytic reaction. There might be some speed control steps at particular pH.