GC–MS-Based Compositional Profiling of Cosmetic Plant Waxes Using Solvent-Dependent Extraction

The utilisation of cosmetic plant waxes as sustainable functional ingredients in personal care formulations is on the rise. This is due to their emollient, structuring and film-forming properties. Nevertheless, the intricate lipid composition of these substances engenders considerable analytical difficulties, impeding the reliable characterisation and quality assessment thereof. In this study, an optimised gas chromatography–mass spectrometry (GC–MS) workflow was developed and evaluated for the compositional profiling of waxes derived from R. succedanea and R. verniciflua, two East Asian botanical species that have historically been utilised in cosmetic and lacquer-related applications. Wax samples originating from China, Vietnam, Korea, and Japan were extracted using solvents of different polarity, including petroleum ether, dichloromethane (DCM), ethyl acetate, and acetone. Following the process of BSTFA derivatisation, the extracts were subjected to analysis by GC–MS to evaluate the efficiency of the extraction process and the chemical composition of the extracts. DCM was found to provide the highest extraction yields and the most representative compositional profiles. Across all samples, palmitic acid was identified as the predominant constituent (80–90%), followed by lower amounts of oleic acid, stearic acid, and minor monoacylglycerols. The proposed analytical workflow exhibited satisfactory reproducibility and effective discrimination of lipid constituents, thereby substantiating its application in comparative compositional evaluation, potential support for future quality assessment studies, and formulation development of cosmetic plant waxes.