茜素红-Cu(Ⅱ)配合物用于荧光法测定废水中的S^2-

Fluorometric determination of S^(2-)by using a complex of alizarin red S and Cu(Ⅱ)

采用荧光光谱法和紫外可见吸收光谱法研究了pH 6.55的Britton-Robin-son(B-R)缓冲溶液中S2-与茜素红(ARS)-Cu(Ⅱ)配合物间的相互作用。S2-的加入使ARS-Cu(Ⅱ)配合物在587 nm处的荧光强度显著增强,并且溶液颜色由红色变成黄色。结果显示:S2-对Cu(Ⅱ)的强结合能力致使配合物ARS-Cu(Ⅱ)分解,释放出ARS,致使体系的荧光光谱和吸收光谱均发生明显变化。S2-浓度在1.02×10-6~2.2×10-5mol/L范围内,体系荧光强度变化与S2-浓度呈良好的线性关系,方法检出限为1.02×10-7mol/L。已用于废水中S2-量的测定,回收率为95.3%~102.0%。

The interaction between alizarin red S （ARS）-Cu（ Ⅱ ） and S^2- was investigated via fluorescence and absorption spectroscopy. In pH 6.55 Britton-Robinson buffer, addition of S^2- into ARS-Cu（ Ⅱ ） system resulted in a fluorescence enhancement at 587 nm. At the same time, the color changed from red to yellow which provided an simple assay of S^2- via naked-eyes. It was assumed that the addition of S^2- led to decomposing of ARS-Cu（ Ⅱ） and ARS was released. A good linear response of fluorescence intensity as a function of S^2- concentration was obtained ranging from 1.02 × 10^-6 to 2.2 × 10^-5 mol/L （ r = 0.9996） with the detection limit of 1.02 × 10^-7 mol/L. Most common ions and compounds didn＇t interfere the determination of S^2- . The proposed method was applied to determining S^2- in waste water and the recoveries were 95.5% - 102.0%.