Determination of Tocopherols and Tocotrienols in Cereals and Nuts by Dispersive Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry
A modified sensitive, rapid and effective method based on ultrasound-assisted dispersive solid-phase microextraction (dSPME) was developed for the determination of tocopherols and tocotrienols in food samples. In this study, multi-walled carbon nanotube (MWCNT) was first used as dSPME material for the pretreatment of vitamin E congeners. Several experimental parameters, including extraction solvent, amount of sorbent, extraction time, and desorption conditions were evaluated. Under optimal experimental conditions, good linearity was observed in the range of 0.01–40 μg/mL with correlation coefficients (r) > 0.998. The method was successfully applied to the analysis of tocopherols and tocotrienols in cereals and nuts samples, and the recoveries of analytes obtained were in the range of 86.1–102.5%. The present method was compared with the classical saponification pretreatment. The results shown that the proposed method was time-saving, convenient, sensitive and suitable for determination of VE congeners in food samples.