Analysis of the polyethylene glycol glucosides and FA esters thereof by atmospheric‐pressure ionization MS

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.