Simultaneous determination of 14 nutrients in vegetable oils by ultra high performance liquid chromatography-tandem mass spectrometry

Abstract

A method for the simultaneous determination of four tocopherols, four tocotrienols, four phytosterols, β-carotene and squalene by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. After saponification, the samples were extracted with petroleum ether, and the extract solution was concentrated by rotary evaporation. The residue was dried under a N2 atmosphere and dissolved with methanol. The 14 nutrients were separated on a Poroshell 120 PFP column (150 mm×3.0 mm, 2.7 μm) by gradient elution with 0.1% (v/v) formic acid aqueous solution and methanol containing 0.1%(v/v) formic acid as the mobile phases at a flow rate of 0.3 mL/min. The detection was performed using an atmospheric pressure chemical ionization (APCI)-mass spectrometer with selective reaction monitoring (SRM) in positive mode. The results were linear in the range of 0.05-10.0 mg/L for the 14 nutrients, and the correlation coefficients (r) were no less than 0.9971. The average recoveries of the 14 nutrients in the vegetable oil samples ranged from 80.7% to 100.5% at three spiked levels, and the relative standard deviations (RSDs) were less than 6.0%. The limits of detection (LODs) ranged from 0.01 to 0.30 μg/g. The limits of quantification (LOQs) were in the range of 0.04-1.00 μg/g. The proposed method is sensitive, accurate, fast and stable, and is suitable for the simultaneous determination of the 14 nutrients in vegetable oil samples.