Spectrofluorimetric determination of total amount of nitrite and nitrate in biological sample with a new fluorescent probe 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s-indacence

A new synthesized fluorescent probe, 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s-indacence (TMDABODIPY), has been used to detect nitrite. When TMDABODIPY reacted with nitrite, a weak fluorescent triazole formed in 0.2 mol l−1 HCl medium at room temperature. The fluorescence quenching intensity was linear over a nitrite concentration of 0.04–0.32 μmol l−1 with a detection limit of 0.3 nmol l−1 (S/N=3). The proposed method has been applied to the determination of total amount of nitrite and nitrate (reduced by Zn powder) in human serum and urine of health and hypertension persons with recoveries of 91.83–101.80%.