溴甲酚紫—十八烷基二甲基苄基氯化铵分光光度法测定水中阴离子表面活性剂

Determination of Anion Surface-Active Agent in water by BCP-SDMBA-Cl Spectrophotometry

建立了溴甲酚紫 ( BCP)—十八烷基二甲基苄基氯化铵 ( SDMBA- Cl)分光光度法测定水中阴离子表面活性剂的方法。实验表明 ,最适合的 p H值为 8左右 ,λmax=588nm,在 1 .0 ml1 .6× 1 0 -4 mol/L SDMBA- Cl存在下 ,十二烷基苯磺酸钠 ( LAS)在 0～ 5.0 mg/L内符合比耳定律 ,其摩尔吸光系数为 4× 1 0 4L· mol-1· cm-1。用此法测定河水和废水中的阴离子表面活性剂 ,相对标准偏差 <3.8% ,样品加标平均回收率为 1 0 0 .3%。

The method of BCP-SDMBA-Cl spectrophotometry is set up to determine anion surface-active agent in water. It shows that LAS content within 0~5 mg/L conforms to Beer's law in pH=8. The major absorptivity is 4×10\+4L·mol\+\{-1\}·cm\+\{-1\} at 588nm. This method has been applied to determine anion surface-active agent in river water and waste water. The relative standard error is lower than 3.8%, The average rate of recovery is 100.3%after adding standard solution into samples.