Spectrophotometric Methods Based on Diazotion-coupling Reaction for the Determination of Aniline Concentration in Water

[Objective] The aim was to establish six spectrophotometric methods for determining aniline concentration in water based on diazotion-coupling reaction.[Method] Aniline coupled with N-(1-naphthyl)-ethylenediamine,α-naphthyl amine,α-naphthol,guaiacol,8-hydroxy-quinoline or chromotropic acid in sodium nitrite medium to form colored dye.[Result] The maximum absorption wavelength of resultant was 545、540、495、450、480 or 510nm,the linear range was 0-5.5,0-6.0,0-6.5,0-11.5,0-10.0 or 0-9.5mg/L,and the limit of detection was 0.009,0.011,0.014,0.032,0.025 or 0.022 mg/L,respectively.The rates of recovery were 95.1-105.3%,and RSDs were 1.96-4.80% respectively.Compared with gas chromatography,no significant difference presented using these 6 methods determining aniline concentration in waste water.[Conclusion] These six methods are simple and accurate and applicable to the determination of aniline concentration in water.