罗丹明B在十二烷基硫酸钠上的Langmuir吸附研究及应用

Langmuir Aggregation of RB on Ionic Surfactant Cetyl Trimethylammonoum Bromide

利用微相吸附 光谱修正(MPASC)技术研究了十二烷基硫酸钠(SLS)与罗丹明B(RB)的结合反应,分析表面活性剂在微量分析中的增效机理。通过在pH=2.0的介质中对RB SLS反应的光谱分析,结果表明:RB SLS间作用符合Langmuir单分子层吸附,产物结合比1∶1,30°C结合常数K=1.0×106;50°C结合常数K=5.03×105。在阳离子表面活性剂存在下,聚集产物中SLS灵敏脱附,籍此定量分析了理发店染发废水和生活污水中阳离子清洁剂,回收率分别为103.3%和95.7%,RSD分别为5.2%和4.7%。

The microphase adsorption-spectral correction (MPASC) technique was applied to the study of the interaction of sodium dodecyl sulfate (SLS) with RB in basic solution. The synergism mechanism of micelle was discussed. The aggregation of RB on SLS surface obeys the Langmuir monolayer adsorption at pH 2.0. Results showed that large micellar aggregates were formed, whese binding constant is 1.0×10~6 at (30°C) and 5.03×10~5 at (50°C)。 The desorption of RB from its SLS aggregate was observed in the presence of cetyltrimethyl ammonium bromide(CTMAB) and the sensitive reaction was used in the determiniation of trace anionic detergent(AD) in water. The recovery is between 103.3% and 95.75% with a relative standard deviation less than 5.2%.