聚乙烯醇增敏藏红T为探针的共振瑞利散射法测定阴离子表面活性剂

在pH=4.0的柠檬酸-柠檬酸钠缓冲体系中,藏红T(ST)与十二烷基苯磺酸钠(SDBS)通过静电引力和疏水作用结合形成离子缔合物,再进一步与聚乙烯醇(PVA)形成三元复合物后,可使体系的共振瑞利散射强度显著提高,其最大散射强度位于340nm处。SDBS含量在0.15~5.0μg/mL范围内与共振瑞利散射强度增强值ΔI呈良好线性关系(R2=0.9969),检出限为8.6ng/mL,据此建立一种定量分析阴离子表面活性剂的共振瑞利散射新方法。探讨了影响因素和最佳实验条件,并将建立的方法应用于环境水样中阴离子表面活性剂的检测。该方法测得结果与国家标准方法相比较无显著性差异。

Resonance Rayleigh Scattering Method for the Determination of Anionic Surfactants Using Safranine T as Probe and Polyvinyl Alcohol as Sensitization

In citric acid-sodium citrate buffer solution(pH=4.0),sodium dodecylbenzenesulfonate(SDBS) and safranine T(ST) could form an ion-association complex by electrostatic attraction and hydrophobic effect,and further form a ternary ion-association complex with polyvinyl alcohol(PVA).The resonance Rayleigh scattering(RRS) intensities were significantly enhanced,and the maximum RRS wavelength was located at 340 nm.The scattering intensities(ΔI) were proportional to the concentration of SDBS over the range of 0.15-5.0 μg/mL.The calibration curve was ΔI =1824.2-192.18c(μg/mL),R2 =0.9969,and the detection limit was 8.6 ng/mL.Accordingly,a RRS method to detect the concentration of anionic surfactants was established.The optimum conditions of the RRS method and the influence factors were investigated,and the method was applied to detect anionic surfactants in environmental water samples with satisfied results.The water samples were also detected by the national standard method,and there was no statistical difference in the results.