MASS SPECTROMETRIC STUDY OF NONYLPHENOL-ETHYLENE OXIDE ADDUCTS

Individual ethylene oxide adducts of high purity have been separated chromatographically from commercial grade nonylphenoxypoly (oxyethylene)-ethanol (TERGITOL nonionic NP surfactants) and studied by time-of-flight mass spectrometric techniques. The 1-9 mole ethylene oxide adducts of nonylphenol produced clearcut spectra with a small number of fragment ions. Four groups of different ion types have been established and some remarks concerning their formation are given. Molecular ions for the nine adducts, through mass 616, were observed in good abundances because of the low-energy and high-speed capabilities of the instrument. However, no single structure for an adduct can be proposed because the nonyl portions of the compounds are isomeric mixtures. The ionization characteristics of the NPEn compounds reveal that the aromatic and alkyl portions of the molecules are easily activated. Tergitol nonionic NP surfactants have branched alkyl substituents and are not completely biodegradable. Therefore it is speculated that the biodegradation process leads to exposure of the highly branched alkylaromatic portions of the molecules in a manner comparable to mass spectral fragmentation processes. © 1969 AOCS Press.