Current sample preparation methods and analytical techniques for the determination of synthetic antioxidants in edible oils

Synthetic antioxidants play a critical role in the storage and process of edible oils due to that they can retard lipid oxidation, maintain the quality of oils, and prolong the shelf life. However, a series of studies have proved the potential risks of synthetic antioxidants for human health when consumed in excess, and many countries have established the permitted amounts of synthetic antioxidants in oils. Thus, the accurate quantification of synthetic antioxidants in edible oils is necessary, and there have developed various analytical methods involved in chromatographical, electrochemical, and spectroscopic methods. Owing to the complex matrix and the incompatibility between the oil sample and the detection instrument, sample preparation is usually adopted prior to the instrument detection to improve the detection effectiveness. The current review aims to provide a comprehensive overview of the recently developed sample preparation methods and analytical techniques applied to determine synthetic antioxidants in edible oils from 2010 to present, with emphasis on the sample preparation methods combined with separation-based analytical techniques such as capillary electrophoresis and liquid chromatography with various detectors. The advantages and limitations of some typical analytical methods are discussed and some insights in the future perspectives are also provided in this review.