Gas chromatographic and mass spectrometric determination of aloe components in skin care cosmetics.

Abstract

Gas chromatographic and mass spectrometric method was applied to the determination and identification of aloe components, barbaloin (BA) and aloenin (AL), in skin care cosmetics. After removal of volatile substances in vacuo, the sample was dissolved in water and treated with Sep-Pak C18 cartridge. The eluate with methanol was evaporated to dryness in vacuo, and a trimethylsilylation was achieved with bis (trimethylsilyl) acetamide and acetonitrile at 70°C for 60 min. The reaction mixture was injected into a gas chromatograph and a gas chromatograph mass spectrometer with a megabore DB-1 capillary column. The recoveries of BA and AL added to the lotion and cream samples were more than 85% in the lotion and more than 67% in the cream, and with the identification limit of 2 μg/g and 4 μg/g, respectively. BA and AL in commercial cosmetics, cosmetic raw materials and aloe leaves were successfully determined and identified.