Abstract: Perfluorinated compounds (PFCs) are extensively utilised within the petroleum industry. PFCs, a class of Emerging Contaminants, have the potential to enter the product chain during the refining process, which could result in environmental pollution and the endangerment of human health. Nevertheless, efficient and reliable methods for the pretreatment and detection of PFCs in petroleum-based samples are still lacking. Consequently, an analytical method was developed in this study, incorporating the extraction of ionic liquids (ILs), the purification of solid-phase extraction (SPE) and the detection of liquid chromatography tandem high-resolution mass spectrometry. Orthogonal Experimental Design was utilised to optimise the key conditions of pretreatment. The following results were yielded by the optimised procedure: The sample was extracted with 0.25 mL of 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF₆). The resulting extract was then diluted to 250 mL, adjusted to pH 5, and subsequently purified by weak anion exchange SPE cartridge. The purified samples were then subjected to separation on a C18 column, which was ionised via electrospray ionisation (ESI) in negative ion mode. Subsequent analysis was conducted by an Orbitrap mass spectrometer in parallel reaction monitoring (PRM) mode. The limit of detection was as low as 0.014 ng/mL, and the limit of quantitation reached as low as 0.059 ng/mL. The analytical method was used for the determination of PFCs in crude oil and FCC tail oil. The detected concentrations were found to be within the range of 0.88-1.47 ng/g and 10.79-17.18 ng/g, respectively, with the recoveries ranging from 58% to 112%. The findings demonstrated the efficacy of the analytical method established in this study in mitigating the matrix effect of petroleum samples, facilitating the effective enrichment and determination of PFCs, and ensuring its general applicability to petroleum samples exhibiting diverse physicochemical properties.