Since alkaloids are basic, I would consider acidic methanol (my preference) or acidic water. I prefer methanol because I feel more alkaloids would be more soluble in this solvent. The acid makes them more soluble in the polar solvent, and reduces the solubility of acidic compounds reducing their concentration in the extract, making for a slightly easier clean-up.

Thank you very much Dr. Silver and Dr. Morris.

Just adding to Dr. Morris' answer, I find an strong cation exchange (SCX) column also does a good clean-up and may even resolve the various alkaloids. Just an alternative to the extraction he mentioned.

Some examples and hints:

http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN40_Purification_of_Alkaloids_with_RediSep_Rf_SCX_Columns.pdf

http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN98_Hints%20for%20Strong%20Ion%20Exchange%20Resins.pdf

Agreed with Dr. Silver and Dr. Morris. I would just like to share some literature regarding alkaloids and their separation from plants which would be useful for you.

Pl. see attached.

Please find attached a book chapter on alkaloids which is worth sharing on this topic.

Regards

Thank you very much Prof. Alok Nahata.

If you want to isolate alkaloids:

There is two main method:

Extract plant material with acidic water, so that alkaloids may isolated as salt.

Basify your plant material either with ammonia or any basic chemicals and extract with chloroform or methanol to isolate alkaloids in basic form.