Fluorescence Spectral Study on the Rhodamine B- I3^- Association Nanoparticle System and Its Analytical Applications

In acid medium, rhodamine B（RhB）, rhodamine S（RhS）, rhodamine 6G（RhG） and butyl rhodamine B（b-RhB） have a fluorescence peak at 580, 549, 553 and 580nm, respectively. BrO^-3 oxidizes excess I^- into I^-3 Rhodamine dyes combine I^-3 to form ion association nanoparticles, resulting in fluorescence quenching at 580, 549, 553 and 580 rim, respectively. The fluorescence quenching intensity is proportional to the concentration of BrO^-3 in the range of 0.020 4 - 0.710 μg/mL for RhB, 0.025 - 0. 512μg/mL for RhS, 0.025 - 0.260 μg/mL for RhG, 0.025 - 1.28μg/mL for b-RhB, respectively. In the four systems, RhB system has good stability and high sensitivity. Thus, a simple, sensitive fluorescence method was proposed for the determination of BrO^-3 in commercial bread additives and flours, with satisfactory results. The results of the fluorescence spectra and scan electron microscopy show that the formation of about 60 ran （RhB - I^-3） n association nanoparticles and the interface between the nanoparticles and solution are main factors that cause the fluorescence quenching.     

漓江底泥对活性艳蓝X-BR的吸附行为研究

采用批式吸附法研究河体底泥对活性艳蓝X-BR的吸附特性．吸附动力学试验结果表明吸附可划分为高速吸附(小于6h)和缓慢吸附(6h以上)两个阶段．活性艳蓝X-BR吸附等温线符合Freundlich方程,pH值、离子强度、温度是影响吸附的重要因素,在pH5左右,色度去除率最高;提高离子强度和温度有利于吸附．     

4,4''''-二偶氮苯重氮氨基偶氮苯与Ni(Ⅱ)的显色反应研究

镍是人体中不可缺少的微量元素,具有非常重要的生理作用近年来,新合成的三氮烯类显色剂是一类广泛应用于钴、汞等过渡金属离子光度分析的优良显色剂4,4'-二偶氮苯重氯氨基偶氯苯可用于钴、汞、银的光度测定,表现了优良的光度性能[1～3],而用于测定镍还未见有报道.本文研究了该试剂在非离子表面活性剂Triton X-100的存在下与镍(Ⅱ)的显色反应,结果表明,在pH9.30的Na2B4O7-NaOH缓冲溶液中,试剂可与镍生成非常稳定的紫红色络合物,镍量在0～0.7 mg/L范围内符合比尔定律,从而建立了分光光度法测定镍的新方法.