TRIAL NUMBER: 02 PERCOLATION I. Goals :Students are able to carry out the extraction process using the method Percolation II. Basic theory A. Definition Percolation is a method of filtering that is done by flowing the filter fluid through moistened simplicia powder. The forces that play a role in percolation include: gravity, viscosity, solubility, surface tension, diffusion, osmosis, adhesion, capillary force and shear force (friction). The percolation method is better than the maceration method because: a. The flow of filter fluid causes the replacement of the solution to occur with a solution of lower concentration, thereby increasing the degree of concentration difference. b. The space between the simplicia powders forms channels through which the filter fluid flows. Because the capillary channels are small, the solvent velocity is sufficient to reduce the boundary layer, thereby increasing the concentration difference. B. Percolation Principle The principle of percolation is the extraction of active substances which is carried out by flowing a solvent through simplicia powder which is first wetted for a certain time, then placed in a cylindrical container which is given a porous partition at the bottom. The solvent is flowed periodically from top to bottom through the simplicia powder and the solvent will dissolve the active substance in the simplicia cells it passes through until it reaches a saturated state. C. Advantages and Disadvantages of the Percolation Method Advantages of the percolation method 1. No additional steps required 2. Does not require heat so this percolation technique is very suitable for substances that are thermo labile 3. Samples are always diary of new solvent 4. The solvent is flowed through the sample so that the filtering process is more complete Disadvantages of the percolation method 1. Contact between the solid sample and the solvent is uneven and limited 2. The solvent becomes cold during the percolation process so it does not dissolve the components efficiently 3. If the sample in the percolator is not homogeneous, it will be difficult for the solvent to reach the entire area 4. This method consumes a lot of solvent and takes a lot of time D. Image of Percolation Tool III. Tools and materials - Percolator Tool - Stirring Rod - 70% alcohol, ethyl acetate, n-hexane - Simplicity IV. Experimental Stages 1. 10 parts of simplicia with a certain degree of fineness, soaked with 2.5-5 parts of solvent. Soaking is done for at least 3 hours in a closed vessel. 2. Prepare a percolator equipped with filter paper and cotton or other porous screen, to hold the simplicia powder. 3. Transfer the macerated simplicia powder, little by little, into the percolator, carefully. 4. Slowly pour enough extracting solvent into the pecolator, until the liquid starts to drip and a layer of solvent remains on top of the simplicia (1-2 cm above the sample surface). 5. Cover the top of the percolator with plastic so that the solvent does not evaporate and leave it for 24 hours. 6. After leaving the mass for 24 hours in the percolator, the percolator tap is opened slightly until the solvent drips at a speed of 1-2 mL/minute 7. Solvent is added repeatedly so that there is always a layer of filter liquid above the simplicia. 8. The drip is carried out until the percolate sample is completely extracted as indicated by a negative chemical reaction. 9. After completing the steps above, the mass is squeezed and the juice is mixed into the percolate 10. Add solvent until the percolate is obtained according to the desired volume. 11. The percolate is then transferred into a vessel, covered and left for 2 days in a cool place, protected from light.