Dosage du Lawsone dans le Henné par la méthode colorimétrique

Abstract

Determination of Lawsone in Henna by the colorimetric method

A modified method is suggested for the measurement of Lawsone in Henna leaves. The crushed leaves were macerated in aqueous saturated sodium carbonate solution and the filtrate was extracted with an equal mixture of ethanol and chloroform which was dried over a waterbath. The dried extract was dissolved in 20% aqueous sodium carbonate solution and the developed color was measured by a spectrophotometer at 510 nm. By this method the concentration of 20 to 100 ug/ml could be measured accurately.