Article ID Journal Published Year Pages File Type
1198819 Journal of Chromatography A 2016 8 Pages PDF
Abstract

•We developed an NPLC–APPI–MS method for the analysis of sterol oxidation products.•The method enables the simultaneous analysis of sterol oxides of all polarities.•Unknown sterol oxides are assigned by retention time comparison with standards.•APPI–MS assists in identifying unknown compounds.

During thermal processing of sterols, complex mixtures of sterol oxidation products may be formed. Here, a new method for the separation and detection of such products is described. The method is based on normal-phase liquid chromatography (NPLC) for separation and atmospheric-pressure photoionization–mass spectrometry (APPI–MS) for detection. The method was optimized using commercial cholesterol oxidation products and tested on an experimentally derived mixture of phytosterol oxidation products. The investigated parameters include solvent and dopant selection, dopant concentration, polar modifiers, the type of stationary phase, and flow rate.Best chromatographic separation and highest sensitivity were achieved using a diol-bonded silica column, employing a solvent system consisting of hexane and isopropanol. The dopant of choice was chlorobenzene, added post-column to the solvent stream at 10% of the flow rate.The developed NPLC–APPI–MS method proved to be a valuable tool for the separation and detection of sterol oxidation products.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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