Analysis and quantification of phenolic compounds in vegetable extracts by high performance capillary electrophoresis (HPCE)

During the last years a growing interest on "natural" compounds, mainly vegetable extracts, has been given. This is related to their antioxidant activity, which is often comparable to that of synthetic molecules having a phenolic structure (such as BHA and BHT) traditionally used as food additives, and their lower toxicity. Moreover, some vegetable extracts having a significant antioxidant power, such as green tea, has been proposed as nutritional integrators to protect against the development of some degenerative diseases. In order to evaluate the amount and the behaviour of antioxidant compounds, mainly phenols and polyphenols, from different vegetable extracts, analytical chemistry should allow a rapid and reliable detection. Phenolic compounds from rosemary, virgin olive oil, and green tea have been numerously analyzed by HPLC, while High Performance Capillary Electrophoresis (HPCE) works are still few on this field. This work shows how HPCE may be an interesting tool to analyze and detect phenols and polyphenols from green tea, rosemary and olive oil extracts, especially for its short analysis time. The here reported HPCE separations were also compared with those realized by HPLC, showing interesting results in terms of efficiency, analysis time and sensitivity.