Quantification of omega-3 fatty acids in dietary supplements and cooking products available on the polish market by thin-layer chromatography–densitometry

Abstract

The effect of omega-3 fatty acids in the human body is multidirectional. They are used in cancer and cardiovascular disease prevention, to stabilize blood pressure, to improve immune function, and in the treatment of concentration disorders. Omega-3 acids, especially eicosapentaenoic and docosahexaenoic acids, are needed for proper human growth. There are several groups of pharmaceutical products containing these compounds, available in pharmacies and markets. Due to a high accessibility of various consumable products such as dietary supplements or food, their quality monitoring is advisable. Therefore, analytical procedures are needed, which will allow the quality of these products to be fast and accurately defined. In our work, thin-layer chromatography (TLC) with densitometric detection was designed for the identification and quantification of the omega-3 fatty acids. The stationary phase constituted TLC silica gel plates activated by AgNO3 solution. As the mobile phase, a mixture of toluene—n-propanol—acetic acid (20:2:0.1, v/v) was used. Detection was performed at 520 nm, after staining with iodine vapor. The method was validated according to the International Conference on Harmonisation (ICH) guidelines. The correctness of the results guarantees good precision and satisfactory recovery (96.59–103.20%). The presented analytical method was used for the determination of omega-3 fatty acids in selected dietary supplements and cooking oils giving satisfactory results.