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

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-2 HPO4 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 Delta F= 165. 4c+2. 5, and the determination range of vanadium is 0. 012-0. 5 mu g . mL(-1), with detection limit of 0. 004 5 mu g . 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 mu g . 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.