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

A method for the simultaneous determination of four tocopherols, four tocotrienols, four phytosterols, ß-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.

[Rapid determination of 15 nutrients in rice by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

A rapid method was developed for the simultaneous determination of 15 nutrients containing eight vitamin E, six γ-oryzanols and ß-carotene in rice by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UHPLC-LTQ/Orbitrap HRMS). The analytes were extracted by methanol containing 0.05% (v/v) 2,6-di-tert-butyl-4-methylphenol (BHT) under the ultrasonic condition, then separated by a Poroshell 120 PFP column (150 mm×3.0 mm, 2.7 µm) with a gradient elution program using 0.1% (v/v) formic acid aqueous solution and methanol containing 0.1% (v/v) formic acid as mobile phases. The detection was performed using an LTQ/Orbitrap HRMS detector with full scan in positive ion mode. Fifteen nutrients were simultaneously separated within 13 min. Furthermore, matrix effects of the white and brown rices were investigated. The correlation coefficients (r) were ≥ 0.9950 in the linear ranges of the 15 nutrients. The limits of detection (LODs, S/N=3) and limits of quantification (LOQs, S/N=10) of the 15 nutrients were 0.2-1.8 µg/L and 0.7-6.1 µg/L, respectively. At the three spiked levels, the recoveries were 73.2%-101.5% with the relative standard deviations (RSDs) ranging from 1.1% to 5.0% (n=3). The method is accurate, efficient and reliable. It is suitable for the simultaneous determination of various nutrients in rice.