Separation and determination of diversiform phytosterols in food materials using supercritical carbon dioxide extraction and ultraperformance liquid ... [An article from: Analytica Chimica Acta]

This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
This paper presents at first time that the ultra-performance(TM) liquid chromatographic atmospheric pressure chemical ionization mass spectrometer (UPLC-APCI-MS) was used as an efficient method for the identification and quantification of diversiform phytosterols in food materials. The sample preparation consisted of extraction by supercritical carbon dioxide fluid extraction (SCE) and saponification by refluxing with ethanolic KOH, and then the non-saponificable fraction was extracted with petroleum ether. This fraction was subjected to solid phase extraction (SPE) on silica gel cartridge and then the sterols were eluted with hexane-ethyl acetate. Sterols were separated on an Acquity UPLC(TM) BEH C18 column (100mmx1.0mm, 1.7@mm particle size) with a gradient of methanol/water (1% acetonitrile) at a flow of 0.1mLmin^-^1. The determination was performed in selective ion monitoring mode. The quality parameter of the developed method was established using 6-ketocholestanol as internal standard. Limits of quantification (LOQ) were 0.1754, 0.0341, 0.0500, 0.0205, 0.0225, 0.3674, 0.0241, 0.0272, 0.0076@mgL^-^1 and 0.1525@mgmL^-^1 for 6-ketocholestanol, desmosterol, ergosterol, cholesterol, lanosterol, cholestanol, campesterol, stigmasterol, @b-sitosterol, and stigmastanol, respectively. The intra- and inter-day determination precision for the 10 phytosterols were less than 5 and 6% in relative standard deviations, and their recoveries were located in the range of 94-107%. The developed approach has been applied successfully for efficient determination of diversiform phytosterols in food materials, including corn, sesame, oat and peanut.