Fast High Performance Liquid Chromatography and Ultraviolet Method for Determination of Phenolic Antioxidants in Fresh Rosemary Leaves.

Abstract

An improved reversed phase  HPLC method is reported for the determination of rosemary's principal phenolic antioxidants, caeffic acid, naringin ,rosmarinic acid ,cirsimaritin,  carnosol  and carnosic acids, providing a fast and simultaneous quantitative  determination for these compounds , The analysis can be accomplished within 10 min under isocratic conditions with 0.1% phosphoric acid-60% acetonitrile as the mobile phase at a flow-rate of 1.5 ml/min, with UV detection at 280 nm. Using efficient reversed phase , Hypersil 5H,C-18 (50x 4.6 mm I.D) column, 3µm particle size, The analysis was performed with fresh methanolic extractions of Rosmarinus officinalis leaves . To quantify the amount of antioxidants in a fast and reproducible way by means of UV–vis absorption measurements, excellent linearity were obtained for all studies standards ,with coerelation coeficients of R value 0.964 and standared deviation were ( SD=0.551), the detection limits were less than 0.1 µg/l. the result observed that the main constituents in the rosemary  leaves were carnosic acid and rosemarinic acid with low concentration of caffeic acid, naringin, cirsimaritinand  carnosol. This UV–vis methodology can be extended to the determination of other compounds and herbs constituents of phenolic antioxidants .

Keywords:Rosmarinus officinalis; antioxidants ; HPLC analysis