Multilevel characterization of marine microbial biodegradation potentiality by means of flow-modulated comprehensive two-dimensional gas chromatography combined with a triple quadrupole mass spectrometer

tThe present research is focused on the use of a triple quadrupole mass spectrometer (QqQ MS) cou-pled with flow modulated comprehensive two-dimensional gas chromatography (FM GC × GC) for amultilevel elucidation of biodegradation potentiality of natural marine microbial populations duringa bioremediation (biostimulation) treatment. The crude oil used for the evaluation of the bioremediationprocess, namely Dansk Blend Pier E1, represents a very complex sample. Hence, in order to understandthe metabolic activity of microbial populations during the bioremediation process, a GC × GC systemwas used. The high separation power has allowed a detailed characterization of the different chemicalfamilies; moreover, thanks to the high acquisition frequency of the QqQ MS spectrometer, both full scanand multiple reaction monitoring (MRM) data were acquired in the same run. By using this system, bothqualitative analysis of untargeted hydrocarbons mixture (crude oil) and qualitative analysis of biomarkercompounds, present in low amount and often hindered under the bulk of the sample (i.e. adamantanes,diamantanes, steranes and hopanes), were performed simultaneously.The bioremediation capability of biostimulated bacteria was evaluated at four (T4), eight (T8) and four-teen (T14) days. Progressive degradation of linear, branched, and aromatic hydrocarbons, adamantanes,and diamantanes has been showed, whereas, results underline the lack of any kind of activity againststeranes, and hopanes.