Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Characterization of Tunable Carbohydrate-Based Materials for Sorption of Oil Sands Naphthenic Acids

Synthetically engineered copolymers are receiving growing attention for sorption and possible degradation of components in oil sands processed water (OSPW). β-Cyclodextrin (β-CD) copolymers, for example, have been shown in recent studies of electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to adsorb oil sands naphthenic acid fraction components (NAFCs). Herein, we report complementary results for atmospheric pressure photoionization (APPI) for characterization of NAFCs in OSPW samples following sorption with cyclodextrin-based copolymers. The materials investigated were β-CD-cross-linked with three different types of diisocyanates, namely, (i) 4,4′-dicyclohexylmethane diisocyanate, (ii) 4,4′-diphenylmethane diisocyanate, and (iii) 1,4-phenylene diisocyanate. The APPI studies revealed variable sorption for a complementary range of NAFCs with compound classes not detected by ESI. For example, sorption was observed for new classes of NAFCs: HC, N1O1, N1O2, ...