GC x GC/TOFMS analysis concerning the identification of organic compounds extracted from the aqueous phase of sugarcane straw fast pyrolysis oil

GC x GC/TOFMS was applied in the characterization of organic extracts, which were obtained by solid phase extraction (SPE) with C18 commercial cartridges and liquideliquid extraction (LLE) using three solvents of increasing polarities (hexane, dichloromethane and chloroform), from the aqueous phase generated during the pyrolysis of sugarcane straw. Many oxygenated compounds were identified and classified as acids, phenols, aldehydes and ketones, with a high predominance of phenolic compounds, mainly catechol. GC x GC/TOFMS coupled to some computational tools allowed the identification and classification of the compounds according to their chemical class, number of carbons, number of substituents in the alkyl chains, molecular weight and main peaks in fragmentation spectra. Some identifications were only possible to detect using spectral deconvolution of the mass spectra, and it was possible to clearly classify a series of alkyl phenols (from C1 to C4 alkyl substitutes) and alkyl benzenediols (probably catechols, from C1 to C3 alkyl substitutes). A sequential combination of the preconcentration of the analytescombined with high-resolution techniques of separation and identification allowed the total characterization of these compounds in the aqueous phase. (C) 2015 Elsevier Ltd. All rights reserved.