含氧有机溶剂对用桑色素荧光法测定钪的荧光性质的影响

用桑色素-氨替比林萃取荧光法,2-苯并喹啉-4-羧酸荧光法测定微量钪的方法已有报道,但这些方法的选择性较差。作者发现加入某些含氧有机溶剂对测定体系的荧光性质有明显影响,较大幅度地提高了反应的灵敏度和选择性。据此,作者建立了在稀土元素共存时,直接测定钪的新方法。本文还测定了桑色素-钪配合物的组成,荧光效率φ,表观稳定常数K,溶剂化数及溶剂化常数K_s,并对有机溶剂的作用进行了初步探讨。

Aqueous solvents effects on the fluorescent properties of fluorometric determination of scandium(III) with morin

The solvent effects on the fluorescent properties of fluorometric determination of Sc with morin was investigated. In the presence of organic solvents, the sensitivity and selectivity of fluorescent reaction were greatly increased, e.g. the fluorescent quantum yield of Sc-morin complex and Sc-morin-n-PrOH are 0.056 and 0.325, resp. A highly sensitive fluorescent method for determination of Sc was proposed in the presence of n-PrOH. Beer's law was obeyed for 0-13 mg Sc/25 mL in the Sc-morin-n-PrOH system. The interference of foreign ions was studied. Satisfactory results were obtained in the determination of trace Sc in rare earth samples. The molar ratio of Sc:morin is 1:3. The solvation no. of n-PrOH is 3. The enhancement of fluorescent quantum yield of Sc-morin complex was decreased with the organic solvents in the order of n-PrOH > iso-PrOH > tert-BuOH > acetone > dioxane > EtOH > MeOH > DMSO > H2O. The solvation nos., stability constants of the complexes, and the spectra were determine for the studied solvent systems.