Harnessing the potential of natural compounds through DES-based DLLME to make greener fragrance analysis: A case study with high water content samples

Gas chromatographic analysis of possible cross-contaminations in perfumes is routinely performed in fragrance quality control laboratories. Conventional analytical methods require either the use of large amounts of organic solvents, or the direct injection of samples, which can lead to interferences and/or require frequent maintenance of the chromatographic system, especially when high water content fragrances are analysed. In this work, a more environmentally friendly approach for the extraction and enrichment of volatile compounds from aqueous perfumes is proposed. The method is based on dispersive liquid-liquid microextraction (DLLME) using a natural-based deep eutectic solvent (DES) as extraction solvent. This new class of natural solvents is characterized by simplicity in synthesis, low cost, environmental friendliness, and (in some cases) natural origin, so it can replace traditional organic solvents. Here, hydrophobic deep eutectic solvents (HDES) consisting of volatile terpenoids and phenols isolated from essential oils and/or other natural products are studied. These natural HDES can be used for the extraction of aqueous samples and, because of their volatility, can be analyzed directly by GC (and GC-MS). The application of HDES in dispersive liquid-liquid microextraction (DLLME) for the extraction of possible cross-contaminants from hydroalcoholic commercial fragrances makes it possible to obtain enrichment factors and analytical figures of merits suitable for their determination, as required in quality control laboratories