Quantitative Determination of Phytosterols and Cholesterol in Food Materials by Gas Chromatography-Tandem Mass Spectrometry

Phytosterols are minor components of plant oils because of their beneficial effect on human serum cholesterol level. They are important structural components of plant membranes such as brassicasterol, campesterol, stigmasterol and beta-sitosterol. Cholesterol is essential for all animal life . It is also a major risk factor for heart disease.

      Food materials were saponified with 7.5% KOH in methanol and then extracted directly with petroleum ether/n-hexane (50:50, v/v). After concentrated with rotary concentrator at 40℃, the residue was reconstituted with tetrahydrofuran. Analysis was performed by GC-EI-MS/MS.

      The quality parameter of the developed method was established using 5-alpha- cholestane as internal standard. Method detection limit (MDL) were 0.40, 0.29, 0.21, 0.19 and 0.16 mg/100 g for cholesterol, brassicasterol, campest-erol, stigmasterol, and beta-sitosterol, respectively. The intra- and inter-day determin-ation precision for the 4 phytosterols and cholesterol were less than 6 and 8% in relative standard deviations, and their recoveries were located in the range of 92–104%. The developed approach has been applied successfully for efficient determination of phytosterols and cholesterol in food materials.

※ author : Yan-Zong Chen, Yu-Man Yu, Yu-Chen Liu, Ju-Ying Li, Tyh-Jeng Ren, Dar-Der Chu, Kun-San Yang, Chung-Wei Tsai^*

※ publisher : 4th AOMSC & 10th TSMS