分光光度法测定水中十六烷基三甲基溴化铵

基于甲基橙(MO)在水体中和阳离子表面活性剂发生的褪色反应,采用分光光度法测定十六烷基三甲基溴化铵(CTAB),优化了试验条件,讨论了干扰物质的影响。MO与CTAB在10%乙醇-水溶液中反应形成淡黄色离子缔合物,以MO的最大吸收波长470 nm为测定波长,CTAB质量浓度在0 mg/L～13.1 mg/L范围内遵守朗伯-比尔定律,吸光系数为17.48 L/(g.cm),方法检出限为0.364 mg/L,标准溶液平行测定的RSD为2.3%,样品加标回收率为91.8%～107%。

SpectrophotometricM ethod for Determ ination of Cetyltrimethyl ammonium Brom ideinW ater

Based on a colour retardation of methyl orange with cationic surface active agent in water,Cetyltrimethyl-ammonium bromide was determined by spectrophotometry.The test conditions were optimized and interfering substances were discussed.Methyl orange reacted with cetyltrimethyl-ammonium bromide forming yellow associated ion pairs.Absorptivity was 17.48 L/（g·cm） in solution of cetyltrimethyl-ammonium bromide ranging between 0 mg/L and 13.1 mg/L,and color absorption obeyed lambert-beer＇s law at 470 nm maximum absorption wavelength of Methyl orange.Detection limit of method was 0.364 mg/L.RSD of parallel standard solution was 2.3%.Spiked recoveries of samples were between 91.8% and 107%.