Essential oils are highly volatile, aromatic concentrated extracts from plants with wide applications. In this study, fast, easy-to-use attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) was combined with chemometric techniques to verify essential oils’ taxonomy and purity. Principal component analysis (PCA) clustered 30 essential oil samples into three different groups based on plant botanical family and concentration. The first group contained highly concentrated oils from the Asteraceae family, the second group contained highly concentrated oils from the Lamiaceae family, while the last group contained three highly concentrated essential oils from different botanical families and commercial-grade essential oils. Thus, commercial-grade oil samples did not cluster with the corresponding concentrated oil samples despite their similar spectral patterns or botanical family. A loading plot identified infrared (IR) bands that correspond to carbonyl, vinyl, methyl and methylene group vibrations as the most important spectral bands that can be used as marker bands for discrimination between different botanical plant family groups. Hierarchical cluster analysis (HCA) confirmed the results obtained by PCA. ATR-FTIR spectroscopy combined with chemometric algorithms provides a direct and non-destructive method for chemotaxonomic classification of medicinal and aromatic essential oils and an assessment of their purity.

中文翻译：

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通过FT-IR光谱和模式识别技术评估精油质量和纯度

香精油是挥发性高的芳香族浓缩提取物，具有广泛的用途。在这项研究中，快速，易于使用的衰减全反射傅里叶变换红外光谱（ATR-FTIR）与化学计量学技术相结合，验证了香精油的分类学和纯度。主成分分析（PCA）根据植物植物科和浓度将30种精油样品分为三个不同的组。第一组包含来自菊科的高浓度精油，第二组包含来自唇形科的高浓度精油，而最后一组包含来自不同植物科的三种高浓度精油和商业级精油。从而，尽管商业级石油样品的光谱图谱或植物种类相似，但它们并未与相应的浓缩油样品聚类。加载图将与羰基，乙烯基，甲基和亚甲基振动相对应的红外（IR）波段确定为最重要的光谱带，可用作区分不同植物植物家族组的标记带。层次聚类分析（HCA）证实了PCA获得的结果。ATR-FTIR光谱与化学计量学算法相结合，为药用和芳香精油的化学分类分类和评估其纯度提供了一种直接且无损的方法。甲基和亚甲基基团振动是最重要的光谱带，可以用作区分不同植物植物家族组的标记带。层次聚类分析（HCA）证实了PCA获得的结果。ATR-FTIR光谱与化学计量学算法相结合，为药用和芳香精油的化学分类分类和评估其纯度提供了一种直接且无损的方法。甲基和亚甲基基团振动是最重要的光谱带，可以用作区分不同植物植物家族组的标记带。层次聚类分析（HCA）证实了PCA获得的结果。ATR-FTIR光谱与化学计量学算法相结合，为药用和芳香精油的化学分类分类和评估其纯度提供了一种直接且无损的方法。