Determination of Trace Nitrite by Catalytic Photometry in System of Nonionic Surfactant

A new catalytic spectrophotometric method for determination of trace NO 2 - was developed. The method was based on the oxidation of neutral red by H 2O 2 catalyzied by NO - 2 in the presence of Tween 80. Because of the addition of Tween 80, the sensitivity was raised by 2.2 times. The linear range of determination is 2～12 μg/L with detection limit of 2.7×10 -10 g/mL. The method was applied to the determination of trace NO 2 - in water samples.