Automated micro-solid-phase extraction clean-up of polycyclic aromatic hydrocarbons in food oils for analysis by gas chromatography - orbital ion trap mass spectrometry

Food can contain unwanted compounds and need to be analyzed for compounds like carcinogenic polycyclic aromatic hydrocarbons to ensure consumer safety. The analytes need to be extracted from the sample matrix and cleaned-up to enable detection. However, established methods for clean-up are labor-intensive and have a high expenditure on organic solvents. Here we show a newly developed micro solid-phase-extraction cartridge method, to automate the clean-up for analysis of polycyclic aromatic hydrocarbons in sunflower oil using GC-Quadrupole-Orbitrap-MS with a TriPlus autosampler. This automated micro solid-phase-extraction cartridge method needs only 4 μL of vegetable oil sample and requires only 360 μL acetonitrile for elution, and, therefore, it needs only small amounts of organic solvent. Two different micro solid-phase-extraction cartridge methods were developed, one using two commercially available cartridges with Florisil and Octadecylsilane /Z-Sep/CarbonX, and the other method using one commercially available cartridge with Florisil followed by one self-made cartridge with Octadecylsilane/Z-Sep. The latter method showed successful lipid removal and was further validated for 22 of 24 polycyclic aromatic hydrocarbon compounds in sunflower oil at a spiked level of 1090 μg/kg with recoveries ranging from 53-118% and relative standard deviation below 22%. This method shows promising short-time clean-up with low expenditure of solvents. This article is protected by copyright. All rights reserved.