It is best not to get dichloromethane on your skin. Gloves are to be worn during this experiment, if improper safety precautions are taken there is a possibility of irritation, and or burning of the skin.
CAUTION:
Gas will build up in the separatory funnel while you are shaking it, so you must vent the funnel occasionally to prevent the stopper from popping out, causing a mess and possibly getting dichloromethane on your skin.
~During the pre-phase of this experiment it is recommended that you prepare all aspects of this experiment ensuring any safety reliability’s. It is recommended that you have chosen a clean safe environment to perform this experiment. All actions taken place during this experiment are under your care and will …show more content…
Add twenty (20) milliliters of dichloromethane and place the stopper in the top of the sep funnel. Shake the funnel for 1-2 minutes being care not to spill its contents. Place the funnel back in the ring stand and allow the two layers of liquid to separate—this may take a few minutes. The lower layer will be dichloromethane. There may be an emulsion at the boundary between the two layers—an emulsion is a region where “bubbles” of one liquid are suspended in the other liquid, and the two refuse to separate. If an emulsion occurs, use a glass stirring rod to poke around in the emulsion to break it up. Be sure the stopper is removed from the top of the sep funnel for the following drainage step—otherwise the liquid will drain out of the funnel extremely slowly. Once the two layers have separated, or are nearly separated, drain the lower dichloromethane layer into a clean, DRY two hundred and fifty (250) milliliter beaker. Be careful not to drain any of the coffee into the beaker. It is best to leave a very small amount of dichloromethane at the bottom of the seperatory funnel so as not to accidently allow some coffee to escape. The dichloromethane just drained contains dissolved caffeine that has been extracted from the coffee. However, it isn’t possible to extract all the caffeine with a single portion of dichloromethane. Therefore, you will do two more extractions using fresh portions of dichloromethane in order to extract the majority of the caffeine that is in the coffee. Set the beaker containing the first portion of dichloromethane