【摘要】 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。更多还原

【Abstract】 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 citrate-Na 2HPO 4 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-PARV(Ⅴ)was established.The equation of linear regression is Δ F =165.4 c +2.5,and the determination range of vanadium is 0.012-0.5 μg·mL-1,with detection limit of 0.004 5 μg·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 μg· 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.更多还原