How To Do Buchner Funnel Vacuum Filtration

Create a quarter-inch filtration patty using Celite 545 in the Buchner funnel. Turn on the vacuum pump and use ethanol to flatten and compress the Celite layer.

Add eight scoops of activated charcoal to the Buchner funnel (two scoops per 250 mL of solution). Pour ethanol over the charcoal layer to wet and flatten it while maintaining vacuum.

Let the prepared filter bed sit for 10-15 minutes while the vacuum is pulling to dry it out completely. After drying, turn off the vacuum pump and empty out the ethanol.

Turn on the vacuum pump and pour the ethanol-material solution into the top of the Buchner funnel. Observe the filtrate becoming clearer as impurities are trapped in the filter bed.

Remove the solution from the collection flask and add activated charcoal directly to it. Pour the charcoal-containing solution back through the Buchner funnel to further purify the product.

Observe colored impurities trapped in the filter bed. The purified filtrate can now be processed using rotary evaporation to remove ethanol, followed by chromatography or distillation for further purification.