Explain step by step how to use a separatory funnel to extract caffeine from an aqueous mixture to the dichloromethane layer as per the PDF procedure.
A) Pour the aqueous mixture into the funnel, shake gently, and allow layers to separate.
B) Add the dichloromethane to the aqueous mixture and shake vigorously.
C) Heat the mixture until caffeine separates, then decant the layers.
D) Mix both layers thoroughly to ensure complete extraction.
