Optimisation of headspace solid-phase microextraction with comprehensive two-dimensional gas chromatography–time of flight mass spectrometry (HS-SPME–GC × GC–ToFMS) for quantitative analysis of volatile compounds in vegetable oils using statistical experimental design

The analysis of volatile organic compounds (VOCs) influencing the aroma of an oil is essential for evaluating its quality. Although a large number of extraction methods exists, the simple and reliable protocols for quantitative analysis of VOCs in oils are scarce. Therefore, this study aimed to develop an analytical methodology using headspace solid-phase microextraction with comprehensive two-dimensional gas chromatography–time of flight mass spectrometry (HS-SPME–GC × GC–ToFMS) for the quantification of the volatile compounds in rapeseed oil that can influence its aroma. The method optimised using design of experiment (DOE) approach was then applied to track changes in VOCs during roasting and the accelerated storage test of rapeseed and camelina oils. The optimal conditions were established at an equilibration time of 6 min and extraction for 38 min at 58 ºC using a Carboxen™/PDMS fibre. The statistical experimental design effectively selected the optimal values of each factor and analysed interactions between them. This methodology proved to be reliable for the routine analysis of oil samples. The proposed protocol can be easily extended to quantify other VOCs and can be used in future studies on the aroma of vegetable oils.