某些酸性三苯甲烷染料与阳离子表面活性剂相互作用的共振瑞利散射光谱及其分析应用

In a thin HCl medium,RRS intensities of an alone CS or acidic triphenylmethane dye (TPMD) are very week. However,when TPMD reacts with a CS to form an ion-associate,the RRS intensity is enhanced greatly and a new RRS spectrum appears. The spectral characteristics of the RRS for the ion-associates and the optimum conditions for the reactions are investigated. The intensity of RRS is directly proportional to the mass concentration of CS in the range of 0—3.5 or 0—5.0 μg/mL. The method has a high sensitivity for the determination of CS,their detection limits are between 3.1 and 9.8 ng/mL depending on the different CS. In this case,most metal and non-metal ions do not interfere,so that the method has a good selectivity. Therefore,a sensitive,selective,simple and rapid method for the determination of CS by RRS is developed. [WT5HZ]

银-邻菲罗啉-酸性三苯甲烷染料体系共振瑞利散射法测定痕量银

在磷酸盐缓冲介质中，PVA-124存在下，当银与邻菲罗啉（phen）形成配阳高子，并进一步分别与溴酚蓝（BPB）、溴甲酚绿（BCG）和溴甲酚紫（BCP）3种酸性三苯甲烷染料（TPMD）反应形成离子缔合物时，共振瑞利散射（RRS）强度急剧增强并产生相应的散射光谱。研究了离子缔合物的共振散射光谱特性以及适宜的反应条件．Ag^＋质量浓度在9．6×10^-3-0＋60μg／mL（BPB体系）、4．5×10^-3～1．00μg／mL（BCG体系）和2．4×10^-3～0．40μg／mL（BCP体系）范围内与RRS增强程度呈良好的线性关系。方法具有较高的灵敏度，不同染料体系的检出限在0．72～1．60ng／mL。方法用于环境样品中痕量银的测定，结果满意。

甲基蓝褪色光度法测定酱油中半胱氨酸含量

在碱性硼砂-氢氧化钠缓冲溶液中,半胱氨酸能与酸性三苯甲烷染料甲基蓝发生加成反应,形成无色的硫醚衍生物,体系的吸光度降低,溶液褪色,最大吸收波长和最大褪色波长均为592 nm。于波长592 nm处测定体系的吸光度,确定最佳反应条件后建立标准曲线,用对照品标准曲线法测定样品中半胱氨酸的含量。半胱氨酸在质量浓度在0.20~2.40 mg/L内,与吸光度差值ΔA呈现良好的线性关系,相关系数r=0.9995,表观摩尔吸光系数为6.752×10^(4) L/(mol·cm)。该方法用于市售酱油和半胱氨酸护肝胶囊样品中半胱氨酸含量的测定,测定值的相对标准偏差(n=6)均小于3%,加标回收试验平均回收率为100.4%(一级酱油)、98.08%(三级酱油),护肝胶囊中测定值与标示量基本一致。建立的方法快速简便、专属性强,结果准确可靠。