Determination of lipophilic compounds in genetically modified rice using gas chromatography-time-of-flight mass spectrometry

An accurate and sensitive method for determining 14 lipophilic compounds, including tocopherols, tocotrienols, sterols and policosanols from rice (Oryza sativa L.) grain was developed using gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOFMS). The method is fast, requiring only 13 min for the GC-TOFMS run. During the validation procedure, the method proved to be sufficiently precise and accurate with respect to the degree of endogenous biological variability found in rice samples. The profiles of the 14 lipophilic compounds of pigmented rice, as well as genetically modified (GM) rice to improve β-carotene, were subjected to principal component analysis (PCA) to evaluate the differences among cultivars. PCA could fully distinguish pigmented rice from non-pigmented rice. However, GM rice could not be separated from its non-transgenic counterpart (Nakdongbyeo). This protocol provides a rapid and feasible method for monitoring the bioactive compounds of rice.