高锰酸钾共振瑞利散射法测定磺胺二甲嘧啶

在0.2 mol/L H_2SO_4介质中,磺胺二甲嘧啶(SM_2)和KMnO_4在加热条件下发生氧化还原反应生成MnO_2微粒,导致共振瑞利散射(RRS)增强,并产生新的散射峰.其最大散射波长位于595 nm附近,散射强度在一定范围内与SM_2的浓度成正比,据此建立了测定SM_2的共振瑞利散射(RRS)新方法.本方法具有较高的灵敏度,检出限为8.6 ng/mL.实验优化了测定条件.考察了共存物质的影响,表明方法具有良好的选择性,用于片剂中SM_2的测定,结果满意.

Abstract：

In 0.20 mol/L H_2SO_4 medium, a redox reaction took place between sulfadimidine (SM_2) and po-tassium permanganate to form MnO_2 particles by heating.As a result, new spectra of resonance rayleigh scattering appeared and their intensities were enhanced greatly.The maximum peak of RRS was located at approximately 595 nm, and the scattering intensities were proportional to the concentration of SM_2.Based on these results, a new method for the determination of SM_2 was established.The detection limit (3σ) was 8.6 ng/mL.The effects of coexistent substances were tested, and the results demonstrated that this meth-od had good selectivity.It has been applied to the determination of SM_2 in tablets with satisfactory results.     

金属离子对二巯基辛酸修饰CdSe/ZnS量子点荧光的无规则影响

以二巯基辛酸为修饰试剂制备了水溶性CdSe/ZnS量子点.报道了Pb~(2+),Cu~(2+),Cd~(2+)和Ag~+对DHLA-QDs荧光的无规则影响.初步探讨了金属离子对二巯基辛酸修饰的CdSe/ZnS量子点荧光强度无规则影响的机理,推测量子点能否用作金属离子探针与其表面修饰基团密切相关.

Abstract：

Water-soluble dihydrolipoic acid capped CdSe/ZnS quantum dots (DHLA-QDs) were prepared by a slight modification of the procedure of precursors. DHLA-QDs are widely used in biological labeling for Water-soluble and biocompatible. Herein, we reported that Pb~(2+) , Cu~(2+) , Cd~(2+) and Ag~+ had great effects on the fluorescence of the DHLA-QDs, but these effects were ruleless. It was speculated that the modified ligands on the surface of QDs played an important role in whether water-soluble QDs were suitable to detect metal ions as fluorescence probes.The possible reason was discussed.