To extract caffeine from coffee, I tried reacting it with baking soda to make tannins more soluble. I then put in salt to push caffeine out of solution. I saturated it with salt and then mixed the solids with acetone to get the caffeine out. There is also some salt in the acetone. Washes with water should remove the salt and tannin salts leaving behind the caffeine(not pure). Would this procedure work? Is there another procedure that would be more efficient and not require DCM.
The popular procedure to experimentally isolate caffeine is sublimation.
Slowly heat a teaspoon of coffee or tea from 150°C to 250°C. Let the sublimated caffeine precipitate at a watch glass cooled with ice. The resublimated caffeine forms white needles that can be identified under a microscope.
The sublimation temperature of caffeine is 178°C.
I did this in a practical lesson in chemistry. We filtered the coffee (1.2um filter paper), concentrated it 10x using distillation and then extracted the caffeine into an equal volume of chloroform in a separatory funnel. After evaporating the solvent, we were left with fairly white powder. It was probably impure, containing lots of other alkaloids.