Deep eutectic solvent-based liquid-phase microextraction coupled with reversed-phase high-performance liquid chromatography for determination of [alpha]-, [beta]-, [gamma]-, and [delta]-tocopherol in edible oils

• Published in: Analytical and bioanalytical chemistry Vol. 413; no. 2; p. 577
• Main Authors: Xie, Qilong, Xia, Ming, Sun, Dekui, Cao, Jiangping, Xiao, Yong, Lin, Mingui, Hou, Bo
• Format: Journal Article
• Language: English
• Published: Springer 01.01.2021
• Subjects: Analysis; Composition; Extraction (Chemistry); High performance liquid chromatography; Identification and classification; Methods; Oils and fats, Edible; Tocopherols; China
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-020-03029-1

For simultaneous analysis of four fat-soluble tocopherols ([alpha]-, [beta]-, [gamma]-, and [delta]-) in edible oils, an efficient and green method using deep eutectic solvent-based liquid-phase microextraction (DES-LPME) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The DESs formed by different quaternary ammonium salts and ethanol were used as the extractants. Tetrabutylammonium chloride (TBAC)-ethanol DES at a molar ratio of 1:2 achieved the best extraction efficiency. Under the optimized conditions, the detection limits were in the range of 2.1-3.0 ng mL.sup.-1. The intra-day and inter-day repeatability were in the ranges of 3.9-5.3% and 4.8-7.1%, respectively, and the recoveries for the real samples varied from 80.7% to 105.4%. The developed method was successfully employed for the determination of all four tocopherol homologues with an RP-HPLC system containing a COSMOSIL [pi]-NAP column in five edible oils collected locally.