吖啶橙-PAR-钒(Ⅴ)能量转移荧光猝灭法的研究及分析应用

Study on the Energy Transfer Fluorescence Quenching Reaction of Acridine Orange-4-(2-Pyridylazo) Resorcinol-V(Ⅴ)System and Analytical Application

在pH 5.5的Na2HPO4-柠檬酸缓冲溶液中,吖啶橙（AO）与PAR-钒（Ⅴ）络合物之间发生有效的能量转移,使吖啶橙526 nm处的荧光猝灭,据此建立了能量转移荧光测定痕量钒的新方法。实验表明,在pH5.5的3.0×10^-5mol.L^-1AO-4.0 mg.L^-1PAR体系中,钒的含量c在0.12-0.5μg.mL^-1范围内与荧光猝灭强度ΔF呈良好线性关系,线性回归方程为ΔF=165.4c＋2.5,方法检出限为0.0045μg.mL^-1,相对标准偏差为0.6%。该荧光猝灭反应15 min内完全,其相对荧光强度在2.5 h内基本保持不变。用该方法测定生物样品中钒的含量,相对误差小于5%,结果满足痕量分析要求。

An energy transfer technique for 4-（2-pyridylazo） resorcinol （PAR）-vanadium（ V）and acridine orange（AO）was studied, and the optimum conditions of energy transfer system were also experimented. It was found that in eitrate-Na2HPO4 buffer solution at pH=5.5, energy transfers from AO to vanadium（ V ）-PAR complexes. A new method based on energy transfer fluorescence quenching for the determination of trace vanadium（ V ）with AO-PAR-V（ V ）was established. The equation of linear regression is AF=165. 4c＋2. 5, and the determination range of vanadium is 0. 012-0. 5 ug · mL^-1 , with detection limit of 0. 004 5 ug · mL^-1. The correlation coefficient is R=0. 998 5, and relative standard deviation is 0. 6%. The fluorescence reaction is completed within 15 minutes, and relative fluorescence intensity remains unchanged for 2.5 hours. The influence of foreign ions on the determination of V （0. 5 9g · mL^- 1 ） was examined, with a related error of 5%. The method has been used in the determination of trace vanadium in biological samples with the relative error of 6. 98%, which meets the requirements of trace analysis.