乙基紫共振瑞利散射光谱法测定葡聚糖硫酸钠

在Britton-Robinson缓冲介质(pH 9.0～10.5)中，单独的乙基紫与葡聚糖硫酸钠的共振瑞利散射都非常微弱，当二者反应形成结合物时将导致溶液共振瑞利散射明显增强，并产生新的共振瑞利散射光谱，其3个明显的散射峰分别位于348.0，509.8和680.0 nm处，且均可作为测定波长。以ΔI值最高且线性关系较好的509.8 nm作为测定波长时，葡聚糖硫酸钠在0.005～2.4 μg·mL-1范围内与共振瑞利散射强度成线性关系，检出限为3.25 ng·mL-1。研究了葡聚糖硫酸钠-乙基紫体系的紫外-可见吸收光谱，讨论了溶液酸度、乙基紫浓度、反应时间、温度、离子强度等实验条件的影响，考察了共存物质对该体系测定葡聚糖硫酸钠的影响。实验表明该方法有高的灵敏度和较好的选择性，应用于合成样品的测定。

Determination of Dextran Sulfate Sodium with Ethyl Violet by Resonance Rayleigh Scattering

In the Britton Robinson buffer medium (pH 9.0-10.5), either dextran sulfate sodium (DSS) or ethyl violet (EV) showed very faint resonance Rayleigh scattering (RRS) spectra. However, when DSS and EV were mixed together, the interaction between DSS and EV by virtue of electrostatic and hydrophobic forces occurred, which greatly enhanced the RRS intensity and a new RRS spectrum for the DSS-EV system appeared with three obvious scattering wavelengths at 348.0, 509.8 and 680.0 nm, respectively. All these RRS peaks increased with the increase in DSS concentration. The maximum scattering wavelength appeared at 509.8 nm; and therefore was selected as the determination wavelength for the system. The RRS intensity was directly proportional to the concentration of DSS in the range of 0.005-2.4 μg·mL-1, and the detection limit was 3.25 ng·mL-1. The characteristics of RRS and absorption spectra of the DSS-EV system, the influencing factors, such as solution pH, EV concentration, reaction time, temperature, and ion strength, and the optimum conditions for the reaction were investigated. The influence of foreign substances on the DSS-EV system was also studied. The method was sensitive and selective, and has been applied to the determination of DSS in synthetic samples with satisfactory results.A new method for the determination of trace amounts of DSS based on the RRS method has been developed.