Photolytic degradation of a homogeneous Triton X nonionic surfactant: nonaethoxylated p-(1,1,3,3-tetramethylbutyl)phenol

Aqueous solutions of 14C-labeled homogeneous nonaethoxylated tert-octylphenol (TOP-9EO) at 0.15% (w/v) concentration were irradiated with 300-nm sunlight lamps. Extraction under basic conditions with ethyl acetate isolated the tert-octylphenylpolyoxyethylene glycols, and extraction with chloroform isolated the polyethylene glycols, glycolic aldehydes, and glycolic ethers. Product purification was by thin-layer and high-performance liquid chromatography. Photoproducts were identified as their 3.5-dinitrobenzoate derivatives using direct exposure chemical ionization mass spectrometry (DCI-MS). Nine herbicides were tested as photosensitizers of TOP-9EO, and eight appeared to provide some effects. Employing sensitizers with known triplet energies, the Et of TOP-9EO was estimated to be 53-54 kcal/mol