十二烷基苯磺酸钠共振瑞利散射和共振非线性散射光谱法测定亚甲蓝

在0.05 mol/L（pH 1.3）的 HCl 介质中，十二烷基苯磺酸钠（SDBS）与亚甲蓝（MB）借静电引力和疏水作用力形成 2︰1 的离子缔合物,导致溶液共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)急剧增强，并产生新的 RRS，SOS 和 FDS 光谱。最大 RRS, SOS 和 FDS 分别位于 310, 647 和 341 nm, 散射强度在一定范围内与MB的浓度成正比，方法具有很高的灵敏度，对于MB的检出限(3?)分别为 1.2 ng/mL (RRS法)、1.4 ng/mL (SOS法) 和 1.7 ng/mL (FDS法)。据此发展了一种测定痕量亚甲蓝的新方法。用于人血清样品中亚甲蓝含量的检测，回收率在 94.4-103.7 ? 之间。实验优化了反应条件，考察了共存物质的影响，并结合量子化学AM1法讨论了反应机理和散射光谱产生及增强的原因。

Determination of methylene blue by RRS, FDS and SOS spectra

In 0.05 mol/L（pH 1.3） HCl medium, SDBS combined with MB to form an ion association complex with the composition ratio of 2∶1 by electrostatic interaction and hydrophobicity effect. As a result, the new spectra of RRS, FDS, and SOS appeared and their intensities were enhanced greatly. The maximum wavelengths of RRS, SOS and FDS were located at 310 nm, 647 nm and 341 nm, and the scattering intensities were proportional to the concentration of MB. These three methods have very high sensitivities, and the detection limits were 1.2 ng/mL for RRS, 1.4 ng/mL for SOS and 1.7 ng/mL for FDS, respectively. At the same time, the methods have better selectivity. Based on the above researches, a new spectral method for the determination of trace amounts of MB has been developed. It can be applied to the determination of MB in human serum with a satisfactory result, and the recoveries are 94.4-103.7%. In this work, the optimum conditions of the reaction and the effects of coexisting substances were investigated. In addition, an AM1 method of quantum chemistry was used for the discussion of the reaction mechanism and the reasons of enhancement of resonance light scattering were discussed.