(1) State Key Lab. of Fine Chemicals, Dalian University of Technology, 158 Zhongshan Rd., 116012 Dalian, P.R. China
Abstract:
Polyethylene glycol (PEG) glucosides (PEGG) and the PEGG esters of lauric acid were analyzed by atmospheric-pressure ionization
MS (API-MS) with electrospray ionization. Straightforward mass characterization of the complex mixtures could be achieved
without prior chromatographic separation. The constituents were identified on the basis of quasi-molecular ions. Individual
components could be observed as protonated molecular ions M+H]+ and/or as their NH4+, Na+, or K+ adducts in positive ion mode. The mass spectrometric investigation showed that mixtures of PEGG consisted of monoglucoside,
diglucoside, polyglucoside, and free PEG. The esterification product is a mixture of two types of nonionic surfactants: PEG-laurates
and PEGG-laurates. The reasons for distortion of the quasi-molecular ion intensities and the stabilization of adduct ions
were discussed. The rapid and highly sensitive API-MS analysis technique proposed here is well suited for direct characterization
of complex mixtures and suitable for development as a routine analytical method.