Step 3: Basification ====================

After de-fatting, slowly add sodium hydroxide to the aqueous solution until the pH is up around 10. Rather than adding dry sodium hydroxide, it may be wise to prepare a solution of sodium hydroxide in water, and add this. Be careful when mixing the sodium hydroxide and water, as the mixture will cause an exothermic (heat producing) reaction. Do not prepare the mixture in heat-sensitive containers. When working with sodium hydroxide, remember that it is a highly caustic material and can burn you badly. Avoid contact, especially with the yes, and if any gets on you wash the spot immediately with plenty of water. It is highly recommended that you wear protective gloves and goggles when working with sodium hydroxide or other hazardous chemicals.

Be aware that once you do this step, you need to continue the extraction at least up through the xylene extraction because leaving the alkaloids in a strongly basic solution will cause them to start breaking down after several hours. Making the solution basic turns the alkaloids into their free base forms, which are soluble in xylene.

Step 4: Extraction of Free Bases ================================

Once the solution is basic, xylene using the same ratio as used during the de-fatting process. Again, mix the solution thoroughly but gently to avoid emulsions. Let the solution sit, and it will separate out into two layers. On the bottom will be a basic aqueous solution, and on the top will be a xylene layer which now contains the alkaloids. Using either a separatory funnel or a siphoning process, collect the xylene layer and set it aside. Since there will still be significant alkaloids in the aqueous layer, repeat this process two more times. Combine all the xylene and discard the remaining aqueous solution.

If you are using a separatory funnel, gas may be formed when adding xylene to the basic solution. To prevent pressure from building up and potentially leading to an explosion, vent the separatory funnel occasionally. If you are using a jar, you should remove the lid.