Giovanna Cafeoa, Giorgia Purcarob, Marina Russoa, Marco Beccariac, Luigi Mondelloa,d, Paola Dugoa,d

aMessina Institute of Technology c/o Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, former Veterinary School, University of Messina, Viale G. Palatucci snc 98168, Messina, Italy;
bGembloux Agro-Bio Tech, University of Liège, Passage des Déportés 2, 5030, Gembloux, Belgium;
cDepartment of Chemical, Pharmaceutical, and Agricultural Sciences, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy;
dChromaleont s.r.l., c/o Messina Institute of Technology c/o Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, former Veterinary School, University of Messina, Viale G. Palatucci snc 98168, Messina, Italy

This study aimed to investigate the content of oxygen heterocyclic compounds, especially coumarin and furocoumarins, in cosmetics products scented with Citrus essential oils. A minor component of the non-volatile fraction of Citrus essences is composed by oxygen heterocyclic compounds, commonly known as coumarins, furocoumarins, and polymethoxyflavones. These molecules show several biological effects on human health. On the other hand, coumarin has the potential to induce skin sensitization and furocoumarins show phototoxic activity. For this reason, over the years several regulation and opinions have been issued concerning the maximum amount of these compounds in cosmetics. 

Given the regulatory framework, an analytical workflow for extraction and quantification of OHCs from cosmetics is necessary. This research aims to address this challenge by exploring, for the first time, a deep eutectic solvent as eco-friendly alternative for microwave-assisted extraction of OHCs from Citrus-scented creams. Due to the complexity of the sample, a SPE clean-up was mandatory to obtain an extract devoid of interferents. Finally, an HPLC-PDA analytical method was employed allowing the simultaneous separation and quantification of 35 oxygen heterocyclic compounds in less than ten minutes. The analytical workflow here proposed was developed, optimized and validated demonstrating the potentials of deep eutectic solvents and microwaves in this field.

Keywords: microwave-assisted extraction (MAE), deep eutectic solvents (DES), oxygen heterocyclic compounds (OHCs), HPLC-PDA