基于荧光光谱技术对常用洗衣粉中表面活性剂含量的测定

Detection of the Surfactant Content in Washing Powder Based on Fluorescence Spectroscopy

十二烷基苯磺酸钠(Sodium Dodecyl Benzene Sulfonate,SDBS)是一种通用的阴离子表面活性剂,其洗涤性能优良,配伍性能好,可与其他无助剂以不同比例配比,且价格便宜,被广泛应用于洗衣粉中。应用FS920荧光光谱仪分析了不同浓度的十二烷基苯磺酸钠水溶液和不同品牌洗衣粉水溶液的荧光光谱特性,发现十二烷基苯磺酸钠溶液的荧光特征峰位于λ_(ex)/λ_(em)=315/350nm,洗衣粉水溶液的荧光特征峰位于λ_(ex)/λ_(em)=356/430nm,经分析是由于洗衣粉中添加了其他非离子表面活性剂、沸石等物质使特征峰发生红移。根据荧光强度与浓度的关系,采用径向基神经网络完成了水溶液中十二烷基苯磺酸钠含量的定量测试,同时通过采用荧光光谱技术和径向基神经网络相结合的检测方法分析了生活中常见的7个常用品牌洗衣粉中表面活性剂的含量。

Sodium dodecyl benzene sulfonate （SDBS） is a generic anionic surfactant. It is widely used in washing powder for its advantages of excellent washing performance, good compatibility performance and lower cost. In the experiment, FS920 fluorescence spectrometer is used to analyze the fluorescence spectral characteristics of both SDBS aqueous solution of different concentrations and detergent solution with different brand. The result indicates that the fluorescent characteristic peak of SDBS and detergent are located in λex/λem = 315/350 nm and λex/λm = 356/430 nm, respectively. By the analysis, it is known that the change of characteristic peak is due to the additives which make the characteristic peak occurres red shift, such as the other non-ionic surfactant and zeolite. According to the relationship between the fluorescence intensity and concentration of SDBS aqueous solution, RBF neural network is used to complete the content quantitative tests of SDBS. At the same time the combined mechod of fluorescence spectrum technology and RBF neural network is used to analysis the content of the surfactant in washing powder of seven commonly used brands in our daily life.