The use of chromatographic techniques for the separation and the identification of insect lipids

The paper presents the state of knowledge on the chromatographic techniques used in the analysis of insect lipids. Lipids are one of the forms of protection against entomopathogenic fungi. Their composition may include a number of different compounds, such as long chain hydrocarbons, waxes, alcohols, aldehydes and free fatty acids. These compounds may be presented in different amounts depending on the species of insects, living environment, lifestyle, seasons, etc. The most commonly used techniques in the analysis of lipids of insects are: gas chromatography, high performance liquid chromatography, and combined techniques such as gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS). Compounds present in the cuticular lipids of insects may serve diverse functions such as minimizing transpiration. It was also found that extracts of insects possess antifungal effects. Determination of lipid profiles and biological activity of the identified compounds can effectively contribute to the knowledge of the defense mechanisms of insects, and thus, impact the development of new methods of combating harmful insects.