Photometric Determination of Polyphenols in Leaves of Acacica Mangium with Folin-Ciocalteu Reagent

Leaves of acacica mangium was powdered and extracted with ethanol (φ 60%).An aliquot of the ethanol extract was reacted with a mixture containing 2 mL of the Folin-Ciocalteu reagent and 18 mL of 100 g·L-1 Na2CO3 solution for 2 h at 30 ℃.The absorbance of the colored solution was measured at the wavelength of 760 nm with 1 cm absorption cell against reagent blank as reference.Catachin standard solution (100 mg·L-1 in absolute alcohol) was used as standard for polyphenol in preparation of standard curve.Range of linearity of the standard curve was kept between 0.8 to 9.6 mg·L-1.Precision was tested by determination of polyphenols in 5 portions of the extract from a same sample,value of RSD (n=5) found was 1.47%.In the test for recovery,8 different amounts of catachin standard were added to the same sample matrix and determined by the present method,values of recovery found were in the range of 98.3%-102.9%.