CATALYTIC-KINETIC FLUOROPHOTOMETRIC DETERMINATION OF TRACES OF NITRITE BY ITS CATALYTIC EFFECT ON FLUORESCENCE-QUENCHING OF SALICYLFLUORONE

It was found that the fluorescence quenching of salicylfluoron (SAF) by oxidation with KBrO3 was catalyzed by the presence of trace amounts of nitrite ion.Using the fixed time method,working curve obtained had the following regression equation,lgF0/F=1.305 c-0.017 5 (r=0.999 0),where c is the concentration of NO-2 ion expressed in μg/25 mL.The linearity range was found to be 0.1-0.5 μg per 25 mL of solution.Detection limit of the method was found to be 1.6 μg·L-1.The proposed method has been applied to the determination of NO-2 in water samples giving RSD′s of analytical results to be 3.7%,and recoveries in the range of 95%-106%.