在pH 2.36的B-R介质中,一定量的3种阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、十二烷基硫酸钠(SDS)和十二烷基磺酸钠(SLS)可与1.0×10-4mol·L-1硫堇溶液1.0 mL在总体积10 mL中反应生成离子缔合物,产生共振瑞利散射光谱,在其最大共振光散射峰655 nm波长处测定共振瑞利散射强度IRRS。SDBS、SDS和SLS的质量浓度分别在0.05~3.0,0.5~3.0,1.0~5.0 mg·L-1范围内与样品及空白溶液的IRRS值之差ΔIRRS呈线性关系,方法的检出限(3S/N)分别为0.017,0.166,0.571 mg·L-1。方法用于两个标准样品和两个环境水样中SDBS的测定,测定结果与认定值和亚甲蓝光度法测得结果相符。

In a B-R buffer medium of pH 2.36, an appropriate amount of anionic surfactant (SDBS, SDS or SLS) sample solution was reacted with 1.0 mL of 1.0×10-4mol·L-1 thionin solution in a total volume of 10 mL, to form an ion association complex, of which the intensity of resonance Rayleigh scattering (IRRS) was measured at the wavelength of 655 nm. Values of ΔIRRS (difference between values of IRRS of sample and blank) was found to keep linear relationships with values of mass concentration of 3 anionic surfactants in the ranges of 0.05-3.0 mg·L-1 for SDBS, 0.5-3.0 mg·L-1 for SDS and 1.0-5.0 mg·L-1 for SLS, with limits of detection (3S/N) of 0.017, 0.166 and 0.571 mg·L-1 respectively. The proposed method was applied to the determination of SDBS in samples of 2 CRM′s and 2 samples of environmental water; results obtained by this method were found to check quite well with certified values and the results found by photometry with methylene blue.