This article describes the analysis of biomarkers in crude oil using the Agilent 7200 GC/Q-TOF system. With a high-resolution time-of-flight mass spectrometer, a diluted sample can be analyzed without fractionation, and the biomarkers of interest can be measured by exploiting the high selectivity of ion extraction at accurate mass. The system has excellent sensitivity, allowing for the selective detection of dibenzothiophene, alkylated dibenzothiophenes, and hopanes. Using the Agilent GC/Q-TOF system in MS/MS mode, low levels of steranes can be selectively detected.
The document describes an analytical method for characterizing crude oil sources and identifying pollution sources by analyzing specific biological markers. The study utilizes a high-resolution time-of-flight mass spectrometer to analyze diluted samples directly without complex fractionation.
Key biomarkers analyzed include alkyl-dibenzothiophenes, hopanes (pentacyclic triterpanes), and steranes (sterol-derived polycyclic alkanes). The text details experimental conditions using an Agilent 7890A GC System combined with a 7200 Q-TOF system. It highlights the advantages of accurate mass determination and MS/MS mode for achieving high selectivity in complex matrices.
The final concentration of the dibenzothiophene reference solution was 0.38 ng/pL.
The final oil concentration after dilution was 1 mg/mL.
The DB-5MS column used was 30 m x 0.25 mm with a 0.25 pm film thickness.