Abstract:

A method for the determination of trace aniline in degradation of printing and dyeing wastewater containing azo dye using the Fenton by liquid chromatography coupled with mass spectrometry was developed. After aniline in the Fenton’s reaction solution was cleaned and enriched by the HLB cartridges, the separation was performed on an  XR-ODS II column by using the mobile phase of acetonitrile, 0.05%  formic acid and 5 mmol/L ammonium acetate solution in gradient elution. Detection was carried out by LC-MS/MS using a positive electrospray ionization interface in the multi-reaction monitoring (MRM) mode. The results show that the HLB cartridge can effectively remove Fe2+ and interfering substance from the Fenton’s reaction solution. Calibration curve was linear within the range of 10.0–1000.0 μg/L with a correlation coefficient 0.9993, and the limit of quantification （LOQ）was 2.0 μg/L. The extraction recoveries were between 93.0%–98.8%, and the intra-day RSDs were of  3.2%–6.9%, and the inter-day RSDs were of  4.8%–6.3%. The developed method is simple, less in disturbance and good in specificity for the satisfactory determination of trace aniline in the Fenton degradation azo dye solution.

Key words: azo dye, oxidative product, aniline, LC-MS/MS