罗丹明B共振光散射法测定阴离子表面活性剂
RLS DETERMINATION OF ANIONIC SURFACTANTS WITH RHODAMINE B
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摘要: 在B-R缓冲溶液中,基于罗丹明B与阴离子表面活性剂(ASF)产生强烈共振光散射增强效应,建立了一种测定阴离子表面活性剂(SDS和SDBS)的方法.试验发现对于SDS和SDBS,最大共振光散射峰位于518和373 nm处.方法具有高的灵敏度,检出限分别为0.023 mg·L-1(SDS)和0.038 mg·L-1(SDBS),用于合成样和环境水样中阴离子表面活性剂含量的测定,回收率为94.0%-105.0%之间,并与亚甲蓝光度法相比,结果满意,可用于环境水样中阴离子表面活性剂的测定.Abstract: By the formation of ion association complexes through the reaction of rhodamine B with anionic surfactants (ASF) in a B-R buffer medium,an increase of magnitude of intensity of resonance light scattering (abbreviated as RLS) was observed.Based on this phenomenon,a new method for the determination of ASF was proposed.Optimum conditions for the reaction were studied and described taking sodium dodecyl sulfonate (SDS) and sodium dodecyl benzene sulfonate (SDBS) as testing objective anionic surfactants.As shown by experimental results,the peak maxima of RLS of the complex of rhodamine B and SDS was found at 518 nm (pH 3.0),and that of rhodamine B and SDBS at 373 nm (pH 3.4),where the measurements of IRLS were taken in the determination of SDS and SDBS.Detection limits of 0.023 and 0.038 mg·L-1 were obtained for SDS and SDBS respectively.In its application to the analysis of some environmental samples,recoveries in the range of 94.0% to 105.0% were obtained.Results obtained by this method were found to be in conformity with those obtained by the methylene blue method.