FI-Chemiluminescence Determination of Nitrite in Tea and Vegetables

Based on the enhancement effect of NO-2 on the chemiluminescence (CL) reaction system of luminol and potassium bromate,and applying the flow injection (FI) technique,a new FI-CL method for determination of NO-2 was proposed.Linearity was kept in the range of 4.0×10-3-4.0 mg·L-1 of NO-2,with a detection limit (3σ) of 2×10-3mg·L-1.Precision was tested at the NO-2 concentration levels of 0.01 mg·L-1 and 0.40 mg·L-1,the values of RSD′s (n=11) obtained were 1.3% and 1.5% respectively.In the application of the proposed method to the determination of NO-2 in tea and vegetable samples,recoveries in the range of 92.3%-108.0% were obtained.