基于水杨基荧光酮的催化动力学荧光熄灭测定痕量亚硝酸根

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

以溴酸钾与水杨基荧光酮的氧化-还原反应为指示反应，以水杨基荧光酮荧光变化为测定依据，系统研究了亚硝酸根催化荧光熄灭反应的动力学条件，建立了水杨基荧光酮催化动力学荧光熄灭法测定自来水中痕量亚硝酸根的方法。用固定时间法得到了良好的工作曲线lgFo／F=1．305c—0．0175，线性范围为0．1～0．5μg／25mL，线性相关系数为0．9990。该方法的检出限为1．6μg·L^-1。水样测定结果的相对标准偏差为3．7％，加标回收率为95％～106％。

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, lgFo/F=1. 305 c-0. 017 5 （r=0. 999 0）, where c is the concentration of NO2- 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 NO2^- in water samples giving RSD＇s of analytical results to be 3. 7%, and recoveries in the range of 95%- 106%.