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On-line liquid chromatography–gas chromatography: A novel approach for the analysis of phytosterol oxidation products in enriched foods

On-line liquid chromatography–gas chromatography: A novel approach for the analysis of phytosterol oxidation products in enriched foods

Authors :
Stefan Wocheslander
Karl-Heinz Engel
Vera Lander
Birgit Scholz
Source :
Journal of Chromatography A. 1396:98-108
Publication Year :
2015
Publisher :
Elsevier BV, 2015.

Abstract

A novel methodology for the automated qualitative and quantitative determination of phytosterol oxidation products in enriched foods via on-line liquid chromatography-gas chromatography (LC-GC) was established. The approach is based on the LC pre-separation of acetylated phytosterols and their corresponding oxides using silica as stationary phase and a mixture of n-hexane/methyl tert-butyl ether/isopropanol as eluent. Two LC-fractions containing (i) 5,6-epoxy- and 7-hydroxyphytosterols, and (ii) 7-ketophytosterols are transferred on-line to the GC for the analysis of their individual compositions on a medium polar trifluoropropylmethyl polysiloxane capillary column. Thus, conventionally employed laborious off-line purification and enrichment steps can be avoided. Validation data, including recovery, repeatability, and reproducibility of the method, were elaborated using an enriched margarine as example. The margarine was subjected to a heating procedure in order to exemplarily monitor the formation of phytosterol oxidation products. Quantification was performed using on-line LC-GC-FID, identification of the analytes was based on on-line LC-GC-MS. The developed approach offers a new possibility for the reliable and fast analysis of phytosterol oxidation products in enriched foods.

Details

ISSN :
00219673
Volume :
1396
Database :
OpenAIRE
Journal :
Journal of Chromatography A
Accession number :
edsair.doi.dedup.....4974d9a76279564268c69bf1cf53bfc9
Full Text :
https://doi.org/10.1016/j.chroma.2015.03.087