Analysis of degradation products of azo dye Orange G under Sono-advanced Fenton oxidation using liquid chromatography–diode array  detection-mass spectrometry — ASN Events

Analysis of degradation products of azo dye Orange G under Sono-advanced Fenton oxidation using liquid chromatography–diode array  detection-mass spectrometry (#127)

Meiqiang Cao 1 , Xiaoqing Wei 1 , Chengyi Shen 1
  1. Zhejiang Gongshang University, Hangzhou, ZJ, China

In this paper, the sono-advanced fenton oxidation (ZAFO) of aqueous solutions of azo dye Orange G was performed at an ultrasonic frequency of 358 kHz using the zero valent iron (ZVI) as a alternative catalyst of ferrous salts in a Fenton process. The effects of various factos such as ultrasound, ZVI, ferric iron and H2O2 addition were investigated on degradation rate. The degradation products formed during sonolysis, ZVI reduction and ZAFO were analyzed  using powerful analytical techniques such as liquid chromatography-electrospray ionization mass spectrometry (LC–ESI–MS), tandem mass spectrometry (MS/MS), and liquid chromatography with diode-array detection (LC–DAD). In order to resolve the MS and MS/MS spectra obtained, the separation conditions were optimized and the best separation with a Shim-pack XR-ODSⅡcolumn was obained using mobile phase 0.2 % acetic acid/acetonitrile in gradient eluent at flow rate of 0.25 mL/min. Based on ultra-violet and visible spectra, [M-H]- ions, and tandem mass spectrometry, sevaral new degradation products were tentatively identified in sonolysis,  ZVI  reducation and ZAFO degradation. Based on this degradation product identification a possible multi-step degradation scheme was proposed for ZAFO degradation.