Determination of Vanillin Compounds in Oilseed Using Solid-Phase Extraction with Ultra-Performance Liquid Chromatography–Mass Spectrometry

Vanillin, methylvanillin, and ethylvanillin are widely utilized as food flavorings. Oilseeds undergo alterations in their flavor profiles during growth, storage, processing, and oil extraction. To accurately identify the source and quantify the content of these three compounds in oilseeds, we have established an analytical method that utilizes solid-phase extraction coupled with ultra-high performance liquid chromatography–mass spectrometry (UPLC–MS/MS). Oilseed samples were crushed and underwent solvent extraction using water, acetonitrile, and n-hexane. The extracted components were then purified through a liquid chromatography C18 solid-phase column, dried under nitrogen, and reconstituted in a methanol–water mixture (4:1, v/v) prior to UPLC–MS/MS analysis. Quantification of vanillin, methylvanillin, and ethylvanillin was achieved using an external standard method. A total of 34 oilseed samples were analyzed to investigate the origin of vanillin. Among these, 30 samples contained varying concentrations of vanillin, ranging from 51.1 to 1774.7 μg/kg. Furthermore, the presence of vanillin in rapeseed oil confirmed that it originated from the raw rapeseed material. The developed analytical method provides a reliable and valuable tool for screening the authentic source and content of vanillin, methylvanillin, and ethylvanillin in oilseeds, ensuring the quality and integrity of the food supply chain.