Essential oils are complex mixtures of organic substances with large commercial importance in the pharmaceutical, food, fragrance, and cosmetic industries due to their organoleptic and biological properties. Also, these materials are also luminescent what has taken several studies about its potential uses for the detection and quality control of essential oils, imaging, and for the investigation of their constituentsâ synergies. Concerning this, the present work is dedicated to studying the optical properties of selected essential oils (EOs): citronella (Cymbopogon winterianus), Japanese mint (Mentha arvensis), clove bud (Syzygium aromaticum), and bergamot (Citrus bergamia). We carried out a comparative study of the photoluminescence (PL) and the UV/VIS optical absorption (Abs-UV/VIS) of these EOs with their typical constituents. To inspect the effects of the intermolecular interactions on the optical response of these systems, mixtures between the EOs constituents following the expected average percent mass fraction were also studied. From these experiments, the main results were: bathochromic effects in the Abs-UV/VIS spectra; excimer formation in citral, isopulegol, isomenthone, eugenol, and eugenyl acetate; excimer emission enhancing and specific solvent effect in the EOs PL spectra. These results contribute to the knowledge of EOâs applications, especially in the evaluation of componentsâ interactions through a simple Abs-UV/VIS assay.

中文翻译：

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EXPRESS：通过吸光度和光致发光对精油进行光学研究

精油是有机物质的复杂混合物，由于其感官和生物学特性，在制药、食品、香料和化妆品行业具有巨大的商业重要性。此外，这些材料也是发光的，已经对其在精油检测和质量控制、成像以及研究其成分协同作用方面的潜在用途进行了多项研究。关于这一点，目前的工作致力于研究选定精油 (EO) 的光学特性：香茅 (Cymbopogon Winterianus)、日本薄荷 (Mentha arvensis)、丁香芽 (Syzygiumaromaticum) 和佛手柑 (Citrus bergamia)。我们对这些 EO 及其典型成分的光致发光 (PL) 和 UV/VIS 光吸收 (Abs-UV/VIS) 进行了比较研究。为了检查分子间相互作用对这些系统的光学响应的​​影响，还研究了符合预期平均质量分数的 EO 成分之间的混合物。这些实验的主要结果是： Abs-UV/VIS 光谱中的红移效应；柠檬醛、异胡薄荷醇、异薄荷酮、丁子香酚和乙酸丁子香酯中的准分子形成；EOs PL 光谱中的准分子发射增强和特定溶剂效应。这些结果有助于了解 EO 的应用，特别是在通过简单的 Abs-UV/VIS 分析评估组分相互作用方面。主要结果是：Abs-UV/VIS 光谱中的红移效应；柠檬醛、异胡薄荷醇、异薄荷酮、丁子香酚和乙酸丁子香酯中的准分子形成；EOs PL 光谱中的准分子发射增强和特定溶剂效应。这些结果有助于了解 EO 的应用，特别是在通过简单的 Abs-UV/VIS 分析评估组分相互作用方面。主要结果是：Abs-UV/VIS 光谱中的红移效应；柠檬醛、异胡薄荷醇、异薄荷酮、丁子香酚和乙酸丁子香酯中的准分子形成；EOs PL 光谱中的准分子发射增强和特定溶剂效应。这些结果有助于了解 EO 的应用，特别是在通过简单的 Abs-UV/VIS 分析评估组分相互作用方面。