The project work to study the efficiency of extraction of tannin from guava leaf to make the ink whiteboard from nature.The dried leaves to crush the 15 g, put down the bottle shaped Apple size 1000 ml Add extract mixture of acetone and ethyl alcohol by volume percentage 60 80% by volume. The 1: Netherland1 number 180 ml, into the jar. Stir well and were refined using machine Rotary Evaporator period 5 hours at 70 degrees Celsius. In order to extract tannin concentrations. Then filter extracts with filter paper. The results showed that15 g period 5 hours. To be effective, and the concentration can be sufficient to ink pen, whiteboard has
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