Two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS) is a powerful tool for identification of compounds in complex samples. Herein, we compared the GC × GC-TOFMS and GC-TOFMS systems for polar metabolite profiling of rice seeds. Forty-seven and thirty-six metabolites were detected in a Korean rice cultivar, Dongjin, using GC × GC-TOFMS and GC-TOFMS, respectively. The limits of detection of shikimic, p-coumaric, and sinapinic acids were 30.0-, 1.6-, and 2.5-times lower, respectively, with GC × GC-TOFMS than with GC-TOFMS. The overlapped peaks of glycerol and phosphoric acid in GC-TOFMS were separated in GC × GC-TOFMS. Polar metabolite profiling of two white and six red rice cultivars was performed using GC × GC-TOFMS and the obtained data were subjected to principal component analysis. Remarkably, principal component 1 separated Heugdaegu from other cultivars, indicating that Heugdaegu has high levels of caffeic, sinapinic, and vanillic acids. Findings from this work may aid breeding programs aimed at improving the quality of rice seeds.

中文翻译：

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使用二维气相色谱-飞行时间质谱法改进水稻（Oryza sativa L.）种子中代谢物的注释和定量

二维气相色谱与飞行时间质谱联用 (GC × GC-TOFMS) 是鉴定复杂样品中化合物的强大工具。在此，我们比较了用于水稻种子极性代谢物分析的 GC × GC-TOFMS 和 GC-TOFMS 系统。分别使用 GC × GC-TOFMS 和 GC-TOFMS 在韩国水稻品种 Dongjin 中检测到 47 种和 36 种代谢物。使用 GC × GC-TOFMS 时，莽草酸、对香豆酸和芥子酸的检测限分别比使用 GC-TOFMS 低 30.0、1.6 和 2.5 倍。GC-TOFMS 中甘油和磷酸的重叠峰在 GC × GC-TOFMS 中分离。使用 GC × GC-TOFMS 对两个白米和六个红米品种进行极性代谢物分析，并对获得的数据进行主成分分析。值得注意的是，主成分 1 将 Heugdaegu 与其他品种分开，表明 Heugdaegu 具有高水平的咖啡酸、芥子酸和香草酸。这项工作的结果可能有助于旨在提高水稻种子质量的育种计划。