HgCl2-头孢噻肟螯合阴离子与碱性三苯甲烷类染料相互作用的共振瑞利散射光谱及其分析应用

在pH为5.3～6.8的Britton-Robinson(BR) 缓冲溶液中, 头孢噻肟钠(CFTM)与HgCl2形成摩尔比为1∶1的螯合阴离子, 它能进一步与结晶紫、甲基紫、乙基紫、亮绿、碘绿、甲基绿和孔雀石绿等碱性三苯甲烷类染料反应形成三元离子缔合物, 导致共振瑞利散射(RRS)的显著增强. 最大RRS峰分别位于367, 367, 340, 367, 340, 340和340 nm附近, 在一定的CFFM质量浓度范围内散射强度与头孢噻肟钠的浓度均呈良好的线性关系. 用结晶紫、甲基紫、乙基紫、亮绿、碘绿、甲基绿和孔雀石绿体系测定头孢噻肟钠的线性范围和检出限(3σ) 分别为0.0090～3.5 μg/mL和2.7 ng/mL, 0.0092～3.5 μg/mL和2.8 ng/mL, 0.013～3.5 μg/mL和4.0 ng/mL, 0.010～3.5 μg/mL和3.1 ng/mL, 0.011～3.5 μg/mL和3.4 ng/mL, 0.012～4.0 μg/mL和3.5 ng/mL以及0.016～3.5 μg/mL和4.7 ng/mL, 其中以结晶紫体系灵敏度最高. 研究了适宜的反应条件和影响因素, 对离子缔合物的组成和离子缔合反应机理进行了探讨, 考察了共存物质的影响, 表明方法有良好的选择性, 据此发展了用HgCl2和碱性三苯甲烷类染料的灵敏、简便、快速测定痕量头孢噻肟钠的新方法.

Resonance Rayleigh Scattering Spectra of the Interactions of HgCl2-Cefotaxime Anionic Chelate with Basic Triphenylmethane Dye and Their Analytical Applications

In pH 5.3—6.8 Britton-Robinson(BR) buffer medium, Cefotaxime sodium(CFTM) can react with HgCl2 to form 1∶1 anionic chelate, which can further react with basic triphenylmethane dye such as crystal violet, methyl violet, ethyl violet, brilliant green, iodine green, methyl green and malachite green to form ternary ion-association complexes. As a result, the resonance Rayleigh scattering(RRS) spectrum was enhanced greatly. The maximum RRS wavelengths of three ion-association complexes were located at 367, 367, 340, 367, 340, 340 and 340 nm, respectively. The increments of scattering intensity(ΔI) were directly proportional to the concentrations of CFTM in certain ranges. The linear ranges and the detection limits(3σ) of CFTM for seven systems were 0.0090—3.5 μg/mL and 2.7 ng/mL(crystal violet), 0.0092—3.5 μg/mL and 2.8 ng/mL(methyl violet), 0.013—3.5 μg/mL and 4.0 ng/mL(ethyl violet), 0.010—3.5 μg/mL and 3.1 ng/mL(brilliant green), 0.011—3.5 μg/mL and 3.4 ng/mL(iodine green), 0.012—4.0 μg/mL and 3.5 ng/mL(methyl green), and 0.016—3.5 μg/mL and 4.7 ng/mL(malachite green), separately. The sensitivity of crystal violet system was higher than those of other six systems. The optimum conditions and the influence factors were investigated, and the composition of ion-association complexes and the reaction mechanism were also discussed. The effects of foreign substances were tested and it is shown that the method has a good selectivity. Based on HgCl2 and basic triphenylmethane dye, the sensitive, simple and rapid method for the determination of trace CTRX was developed.