Senior Scientist Unilever Foods Innovation Centre Wageningen, Netherlands
Abstract: Edible oils and fats consist of a large number of (classes of) compounds. Each of these will contribute to the quality and safety of the lipid sample. Sometimes minor species are important, for example in case of process contaminants, sometimes information on the main groups, e.g. the triacylglycerides, is needed. Over the years scientists have developed a large toolbox of methods, some fast, others slow, some highly selective, others providing a broad overview of species present. Especially methods based on combinations of chromatography with mass spectrometry have proven to be highly useful and versatile.
Our work over the years has focused on speed and automation. Here speed not just refers to analysis time, but also to the time needed for method selection and system optimization. Fast gas chromatography can be applied to monitor quality markers as e.g. hexanal with run times of just a few minutes. Direct fast GC-MS can also be applied for rapid intact glycidylester analysis. Normal-phase LC-MS can be applied to monitor multiple species including oxidized lipids, MCPD esters and other contaminants in edible oils in a single run. Derivatization strategies can be applied to increase sensitivity and selectivity. On-line sample preparation will increase speed and reduce hands-on time.
An important development is the introduction of comprehensive two-dimensional methods. These methods can provide highly detailed information. Comprehensive NPLC×GC, for example, allows to monitor wax-esters, alkanes, partial glycerides, sterols and sterol-esters in olive oil samples of varying quality. Comprehensive GC×GC can be used for enhanced cis/trans fatty acid analysis. LC×LC finally allows to obtain detailed information on oxidized lipids in complex aged frying oils. In the presentation applications of simple and more advanced methods will be discussed.
