用蛋白质作探针共振瑞利散射和共振非线性散射法测定硫酸软骨素A

在pH值为2.5~4.0的BR缓冲溶液介质中，牛血清白蛋白(BSA)、糜蛋白酶(Chy)和α-淀粉酶(α-Amy)等蛋白质与酸性多糖硫酸软骨素A(CS)形成结合物。 此时将会使共振瑞利散射(RRS)和二级散射(SOS)、倍频散射(FDS)等共振非线性散射的强度显著增大。 在蛋白质过量时，3种散射增强(ΔIRRS、ΔISOS和ΔIFDS)均在一定范围内与CS的浓度成正比，方法具有高灵敏度。 当用Chy、BSA和α-Amy作探针时，3种散射法对于CS的检出限分别在1.4~5.8 μg/L、2.0~13.2 μg/L和1.8~9.6 μg/L。 其中以Chy-CS体系的RRS法最灵敏(检出限1.4 μg/L)，可用于痕量CS的测定。 研究了反应体系的RRS、SOS和FDS的光谱特征、适宜的反应条件和影响因素，并以Chy-CS体系为例考察了共存物质的影响，方法有良好的选择性，将其用于滴眼液中CS的测定，取得了较好的结果。

Determination of Chondroitin Sulfate A by Resonance Rayleigh Scattering and Resonance Non-linear Scattering with Proteins as Probes

In a pH 2.5~4.0 Britton-Robinson(BR) buffer medium, some proteins such as bovine serum albumin(BSA), Chymotrypsin(Chy) and α-amylase(α-Amy) can react with chondroitin sulfate A(CS) via electrostatic force, hydrogen bond force or/and hydrophobic force to form binding products. As a result, the resonance Rayleigh scattering(RRS), second order scattering(SOS) and frequency doubling scattering(FDS) were enhanced greatly with new scattering spectra appeared. The increments of scattering intensity(ΔI) were proportional to the concentration of CS in certain ranges. The detection limits(3σ) of CS in Chy, BSA and α-Amy systems were 1.4, 2.0 and 1.8 μg/L(RRS method), 2.3, 2.9 and 2.5 μg/L(SOS method), 5.8,13.2 and 9.6 μg/L(FDS method), respectively. Among them, the RRS method exhibited the highest sensitivity and the Chy-CS system was more sensitive than others. The characteristics of the spectra and optimal conditions of RRS method were investigated. The effects of external substances were tested. The established methods have a good selectivity and can be applied to the determination of CS in eye drops with satisfactory results.