Fabila, Melendie H., Sobreguel, Jonelo T. (April 2004)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
The crude tannin extracts from common weeds Eclipta alba and Cyperuus brevifolius were extarcted using the hot water extraction method employed by the National Science Development Board and Manas (1978). The 1:5 solid to water ratio was used which yielded to 50.94% of the total percentage weight of Eclipta alba; and 25.72% of Cyperus brevifolius. Each crude extract showed qualitatively the presence of tannin when subjected to different tests. Tannic acid ink was also detected when Ferric chloride reacted with the aqueous solution of crude tannin extract.