SPECTROPHOTOMETRIC DETERMINATION OF PHENOL COMPOUNDS FROM HERBS OF CORNFLOWER BLUE

Abstract

There was studied one- and three-fold solid-liquid extraction of natural phenolic compounds (NPC) (in terms of rutin and tannin) from various morphological parts of blue cornflower (Centaurea cyanus L.) on an ultrasonic device created in the research laboratory of the design bureau of the ISS (Voronezh). The optimal time of solid-liquid extraction at the ultrasonic unit has been determined, taking into account wetting and swelling of vegetable raw materials. The quantitative content of NPC (in terms of rutin and tannin) as a percentage of the total content in raw materials at the first stage is about 60%, at the second stage is 25%, and the third one is 18%. It was established that with threefold extraction, the yield of NPC from medicinal plant raw materials increases at the average of 8–10% compared with a one-time extraction. There is offered an improved technique of solid-liquid extraction on the ultrasound unit and UV spectrophotometric determination of NPC from different morphological parts of the blue cornflower. The technique is characterized by the absence of a systematic error, and the relative error at a confidence level of 0.95 does not exceed 5%. The duration of the analysis, taking into account the stage of wetting and osmotic swelling, triple extraction on the ultrasound unit and UV spectrophotometric determination of rutin and tannin in water-ethanol extracts is 40–45 minutes.