Skin is an active metabolic tissue that synthesizes a variety of complex lipid compounds. Sebum, an oily material secreted by the skin, is known to provide a moisturizing effect, sunlight protection, and antibacterial protection for the skin surface. Sebum consists of a complex mixture of free fatty acids, squalene, cholesterol, wax esters, diacylglycerols and triacylglycerols. These species and their concentrations vary depending on skin conditions.
Lipid compounds are generally measured by using GC–FID, GC–MS or LC–MS. However, these methods are often unable to separate all of the individual compounds under the same measurement conditions. In addition, it can be difficult to definitively identify each lipid compound due to co-elution.
On the other hand, two-dimensional GC - high resolution time-of-flight mass spectrometry (GCxGC–HRTOFMS) is a powerful tool for identifying analytes in complex mixtures such as crude oils. The purpose of this work is the comprehensive detection and identification of lipid compounds in sebum by using GCxGC-HRTOFMS.