Abstract In the Brazilian Amazon, many plants are important in the economic context, since they can be obtained from raw material for the most diverse commercial applications. Oils extracted from plants in general are in this context. Bertholletia excelsa produces one of the best-known fruits of the Amazon, the Brazil nut, from which the oil of the same name is extracted, object of study in this work. In the present work the vibrational study of the oil of Brazil nut was performed by Raman spectroscopy (RS), since it is a technique of rapid evaluation in the physical-chemical study, since any preparation of the sample is excluded and can be performed often on-site, and with as little time as possible. For the analysis, a monochromatic source Raman spectrometer with excitation frequency of 633 nm was used. In addition, the spectral formation was discussed based on the chemical composition of the sample by density functional theory (DFT) in order to compare and understand the vibrational nature of the sample. The results showed intense vibrational bands from fatty acids with C–C, C=C and O–H bonds. A brief approximation with calculated first principles was used to predict results. The present work also aims to show that RS technique contributes in a safe and fast way for qualitative analyzes in natural oils.

中文翻译：

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Bertholletia excelsa 油中的拉曼光谱和 ab-initio 计算

摘要 在巴西亚马逊地区，许多植物在经济方面很重要，因为它们可以从原材料中获得，用于最多样化的商业应用。从植物中提取的油一般都属于这种情况。Bertholletia excelsa 生产亚马逊最著名的水果之一，巴西坚果，从中提取同名油，这是这项工作的研究对象。在目前的工作中，巴西坚果油的振动研究是通过拉曼光谱 (RS) 进行的，因为它是物理化学研究中的一种快速评估技术，因为样品的任何制备都被排除在外并且可以经常进行现场，并尽可能减少时间。对于分析，使用激发频率为 633 nm 的单色源拉曼光谱仪。此外，通过密度泛函理论（DFT）基于样品的化学成分讨论光谱形成，以比较和理解样品的振动性质。结果显示来自具有 C-C、C=C 和 O-H 键的脂肪酸的强烈振动带。使用计算的第一原理的简要近似来预测结果。目前的工作还旨在表明 RS 技术以安全、快速的方式为天然油的定性分析做出贡献。