Research and analytical application on determination of trace nitrite by flow injection chemiluminescence analysis

Based on the principle of the reaction of NO2-with I-and formation of I2 in HCl solution,and the chemiluminescence(CL) reaction between luminol and I2 in an alkaline medium.A fairly sensitive,simple and rapid flow-injection analysis-chemiluminescence method for the determina-tion of trace nitrite with the luminal-I——NO2-coupling luminescence system has been developed.Experiment conditions of flow-injection analysis are optimized.When satisfying the condition that Luminol as 4.0×10-4 mol/L,0.7 % KI,0.04 mol/L HCl;the length of reaction coil as 250 cm;the velocity of primary pump as 10r/min;the velocity of ancillary pump as 20 r/min.Under optimum conditions,the detection limit for NO2-is 0.5 μg/L,the linear range of the determination is 1.0～100.0 μg/L.The method can be applied to determination of trace NO2-in environmental water and green stuff with satisfactory results.