Analysis of PAHs in oily systems using modified QuEChERS with EMR-Lipid clean-up followed by GC-QqQ-MS

Abstract

Polycyclic aromatic hydrocarbon (PAH) analysis in oily matrices is a great challenge that needs improvements both in efficiency and environmental sustainability. In this study, a method based on QuEChERS and gas chromatography-quadrupole tandem mass spectrometry (GC-QqQ-MS) was established. The method was based on EMR-Lipid as the dispersed solid phase adsorbent and acetonitrile: acetone (3:2, v/v) as the extraction solvent. The recovery of 16 PAHs reached 66.72–112.87%; the RSD was less than 8%, and the LOD and LOQ were lower than 0.13 μg/kg and 0.43 μg/kg, respectively. Compared to the ISO 15753 method, our method reduced the pretreatment time by 2/3 and improved the recovery of heavy PAHs, such as fluoranthene, benzo[a]anthracene and benzo[b]fluoranthene. The low solvent usage of 10 mL was also environmentally friendly for a high throughput basis. After verification, the method was successfully applied to determine the PAHs in 12 real oily samples, including waste frying oils (WFOs) and vegetable oil deodorizer distillates (VODDs). The PAH concentrations determined in the WFOs and VODDs ranged from 39.21 to 197.44 μg/kg and 1219.34–1482.25 μg/kg, respectively. Our work suggests that the proposed method can serve as an alternative approach for the efficient and precise determination of PAHs in edible oils and other oily systems as well as a potential analytical approach to evaluate PAHs in foods and drinks. Furthermore, the PAH data for the WFOs indicate that the PAH level should be introduced as a safety index for the obsoleting of frying oil.