Assessment of Adulteration of Cosmetics Based on Vegetable Oils by GC-FID and Lipid Profile Using Direct Infusion Electrospray Ionization Mass Spectrometry (ESI-MS)

Vegetable oils have properties that are beneficial to the human skin, and so, they are being used increasingly as ingredients of many cosmetic preparations; however, they are targets of adulteration. This study will evaluate the authenticity of Brazilian cosmetics based on vegetable oils (sesame, peanut, sunflower, and almonds) to determine the composition of fatty acids by gas chromatography with flame ionization detection (GC-FID) and the percentage of fatty acids in conjunction with chemometric treatments (principal component analysis), and lipid profiles using direct infusion electrospray ionization mass spectrometry (ESI-MS). The results obtained were compared with the respective pure vegetable oils. Of the seven brands analyzed, three were revealed as authentic, three were found to be adulterated with the addition of large amounts of soybean oil, and one showed no vegetable oils. These results demonstrate the relevance of quality control for cosmetics based on vegetable oils, which are more susceptible to adulteration owing to their higher cost when compared with vegetable oils such as soybean.植物油具有益于人体皮肤的特性，因此愈发广泛地被用作各类化妆品制剂的原料；然而，植物油亦成为不法掺假的常见对象。本研究旨在评估以芝麻、花生、向日葵及杏仁油等植物油为原料的巴西化妆品的真伪：采用气相色谱-火焰离子化检测法（gas chromatography with flame ionization detection, GC-FID）测定脂肪酸组成，结合化学计量学处理（chemometric treatments）与主成分分析（principal component analysis）计算脂肪酸占比，并通过直接注入电喷雾电离质谱法（direct infusion electrospray ionization mass spectrometry, ESI-MS）获取脂质谱图。将所得检测结果与对应纯植物油的基准参数进行比对。本次分析的7个受试品牌中，3个经鉴定为真品，3个因掺入大量大豆油被判定为掺假，剩余1个品牌未检出任何植物油成分。上述结果凸显了植物油基化妆品质量管控的必要性：相较于大豆油等普通植物油，作为化妆品原料的植物油成本更高，因此更易遭受不法掺假。