Optimization of QuEChERS cleanup for quantification of γ-oryzanol in vegetable oils by UHPLC-MS/MS

Abstract

This study was based on QuEChERS cleanup coupled with UHPLC-MS/MS for the determination of γ-oryzanol compounds in vegetable oils. Several parameters of QuEChERS and UHPLC-MS/MS were studied for purification and detection of γ-oryzanol compounds in oil samples. Under the optimized conditions, the whole pretreatment procedure could be accomplished within 10 min without tedious procedure, larger volume of organic solvent and complicated apparatus. The limit of detections and the limit of quantifications for γ-oryzanol compounds were ranging from 0.1-0.3 µg kg^-1 and 0.4-1.0 µg kg^-1, respectively. Satisfactory recoveries of all analyts were ranging from 72.2 % to 101.3 %, and the intra-day and inter-day precision were less than 10.6 %. The validation indicated that rice band oil and corn oil were rich in 24-mCAF, CAF, β-SIF, CMF and STF. The QuEChERS-UHPLC-MS/MS simultaneously quantified five γ-oryzanol compounds in lipid matrices and assessed the nutritional and functional substances of vegetable oils.

Keywords: Cleanup; QuEChERS; Quantification; UHPLC-MS/MS; Vegetable oil; γ-Oryzanol.

Fig. 1

Typical MRM chromatograms of γ-oryzanol spiked at 2 μg kg⁻¹ in rice bran oil.

Fig. 2

Optimization of QuEChERS conditions: (a) extraction solvent, (b) extraction volume, (c) extraction time, (d) purification materials and amount. The oil samples were spiked with γ-oryzanol compounds at 50 µg kg⁻¹.

Fig. 3

Types and content of γ-oryzanol compounds in vegetable oils.