Validation of an LC-MS/MS method for the quantitation of phytosterols derived from Aloe vera gel

A method to quantitate five minor phytosterols named Aloe sterols identified from Aloe vera gel was validated using AVGP (Aloe vera gel powder) as the sample. To measure the Aloe sterols content, AVGP was extracted with chloroform/methanol (2:1, v/v) and analyzed by liquid chromatography-tandem mass spectrometry. The calibration curve revealed a high coefficient of determination (>0.999). The limit of quantification was 2.3-4.1 ng/mL. Average recoveries ranged from 95 to 105%. The intra-day and inter-day precision were 2.6-6.4% and 3.8-7.3%, respectively, confirming good method precision. Aloe sterols were also quantified in AVGE (Aloe vera gel extract) using this method. We showed that the composition ratio of each Aloe sterol in AVGP did not change in AVGE. Additionally, we measured the concentration of Aloe sterols in the capsule containing AVGE, and confirmed that it was stable even after 1 year of storage. In conclusion, a quantification method was established to simultaneously measure multiple plant sterols with similar structures. • A quantification method to simultaneously measure several plant sterols with similar structures was established. • Results from the intra-day precision and the inter-day precision confirmed good precision. • This method can be applied to processed raw materials and/or foods in long-term storage.