A modified commercial gas chromatograph for the continuous monitoring of the thermal degradation of sunflower oil and off-line solid phase extraction gas-chromatography-mass spectrometry characterization of released volatiles

I Ontañon; J Sanz; A Escudero; S de Marcos; V Ferreira; J Galbán

doi:10.1016/j.chroma.2015.02.001

A modified commercial gas chromatograph for the continuous monitoring of the thermal degradation of sunflower oil and off-line solid phase extraction gas-chromatography-mass spectrometry characterization of released volatiles

J Chromatogr A. 2015 Apr 3:1388:52-9. doi: 10.1016/j.chroma.2015.02.001. Epub 2015 Feb 11.

Authors

I Ontañon¹, J Sanz², A Escudero³, S de Marcos², V Ferreira¹, J Galbán²

Affiliations

¹ Laboratory for Flavour Analysis and Enology (LAAE), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, E50009 Zaragoza, Spain.
² Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, E50009 Zaragoza, Spain.
³ Laboratory for Flavour Analysis and Enology (LAAE), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, E50009 Zaragoza, Spain. Electronic address: escudero@unizar.es.

PMID: 25725960
DOI: 10.1016/j.chroma.2015.02.001

Abstract

A homemade flow cell attached to a commercial Gas Chromatograph equipped with a Flame Ionization Detector (FID) has been designed for the continuous monitoring of volatile compounds released during heating edible oils. Analytical parameters such as mass of sample, temperature and flow rates have been optimized and the obtained results have been compared with the corresponding thermographs from standard TG systems. Results show that under optimum conditions, the profiles of volatiles released upon heating are comparable to the profiles of TG curves, suggesting that the FID based system could be an alternative to TGA. Additionally, volatiles have been retained in a Lichrolut EN(®) resin, eluted and analyzed by Gas Chromatography-Mass Spectrometry. In this case, forty five compounds have been identified (acids, alcohols, alkanes, aldehydes, ketones and furans) and compared with the FID signals, working both in air or nitrogen atmosphere. It has been concluded that the oxidative thermal degradation is prevented in the presence of a nitrogen atmosphere.

Keywords: FID; SPE–GC–MS; Sunflower oil; Thermal degradation; Thermogravimetry.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chromatography, Gas / methods
Flame Ionization / methods*
Gas Chromatography-Mass Spectrometry / methods*
Hot Temperature*
Plant Oils / analysis*
Plant Oils / isolation & purification
Solid Phase Extraction / methods*
Sunflower Oil
Thermodynamics
Volatile Organic Compounds / analysis*
Volatile Organic Compounds / isolation & purification

Substances

Plant Oils
Sunflower Oil
Volatile Organic Compounds