A new method based on the nitration reaction with resorcinol was proposed to broaden the linear range of spectrophotometric determination of nitrite in water. In an hydrochloric acid medium,nitrite reacted with resorcinol to form 4-nitrosobenzene-1,3-diol that rapidly isomerized to orange-yellow 2-hydroxy-p-benzoquinone oxime in an alkaline medium with pH of 9. 97. The absor-bance of the resulting compound was measured at 351 nm using a spectrophotometer. It was shown that there exists a good linear corre-lation between the absorbance and nitrite concentration within the range of 0. 08 mg/L to 1. 40 mg/L,and the detection limit of the method is 0. 02 mg/L. This method has been successfully applied for the determination of nitrite in river water and pond water with the recovery between 96. 3％～102. 0％ and the relative standard deviation less than 2. 35％. Also,the measured values are in well agree-ment with the reference values obtained from standard methods. This method provides a new approach and perspective for the measure-ment of nitrite in environmental water.
维普
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