Spectroscopic analysis of heterogeneous photocatalysis products of nonylphenol- and primary alcohol ethoxylate nonionic surfactants

Nonylphenol ethoxylate (NPE) and primary alcohol ethoxylate (PAE(9-6)) were degraded using heterogeneous photocatalysis. An aqueous surfactant solution (2L, 2000 mg/L) containing TiO2 catalyst (0.1 % w/v) was irradiated with a 400W Blacklight lamp. Analyses of the starting material and degradation intermediates were performed using gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), electrospray mass spectrometry (ESMS) and nuclear magnetic resonance spectroscopy (NMR). Identified intermediates suggested that the ethylene oxide chain was more susceptible to degradation than aliphatic or aromatic moieties. Competitive degradation was also observed. NPE was degraded more rapidly than PAE(9-6).