I usually extract with methanol.

I then partition the extract between acidic water and dichloromethane. After separation, I make the aqueous solution basic and extract again with dichloromethane, which will contain the free-bases.

Another method is to extract with methanol, and then load on to an ion-exchange column (Strong cation exchange). This has the advantage of potentially resolving the different alkaloids in a sample.

See:

http://www.teledyneisco.com/en-us/liquidChromatography/Chromatography%20Documents/Application%20Notes/Purification%20of%20Alkaloids%20with%20RediSep%20Rf%20SCX%20Columns%20App%20Note.pdf#search=SCX

http://www.teledyneisco.com/en-us/liquidChromatography/Chromatography%20Documents/Application%20Notes/Hints%20for%20Strong%20Ion%20Exchange%20Resins%20App%20Note.pdf#search=SCX

http://www.teledyneisco.com/en-us/liquidChromatography/Chromatography%20Documents/Posters/Facile%20Isolation%20and%20Purificatoin%20of%20Alkaloids%20with%20Strong%20Cation%20Exchange%20Columns%20Poster.pdf#search=SCX

I totally agree, acid-base extraction is ideal for alkaloids.

Thank you so much for your responses. Very thoughtful of you.

You need to first select the plant whether it should be extracted for alkaloids or not? Mayer test is helpful for quantitative analaysis. Then after selecting a proper specie need removes fats from it by using n-hexane.

After this dry the plant material and the moistioned it by using ammonia solution for 2 to 3 hrs to let alkaloids free. After that can be extracted by a variety of solvents, like dichloromethane, chloroform, ethanol, acetone, methanol by using different techniques sockslet methods etc. No set parameters.

I used three four solvents of different polarity so I got different fractions in the beginning. But everytime when you change the solvent make it sure that plant material should be completely dried.

After this I condensed the crude. Then I dissolve the crude in respective solvent in which it was extracted may be taking 1 to 2 liters of that solvent and extract it through solvent-solvent extraction by using 5%HCl and checking the presence by using Mayar reagent. Till all alkaloids moved to the aqueous layer. After this I basify the aquous layer by using NaOH inside a ice-bath till pH 9-10. To let alkaloids free. After that I again repeat solvent extraction by using same solvent of extraction once again and again check the presence of Alkaloids in two in two layer by using Mayar reagent. The simply add anhydrous salt to remove all water from organic svent like sodium sulfate over night then I condensed the crude having 80-90% alkaloids called crude alkaloid. Hope u shall understand. I always did cold extraction as no artifacts.

Dear Mr. Qureshi,

Sounds practicable; need to review the procedure a couple of times to fully get the idea, though. Thank you for your time and perfectly detailed respond my friend.

If any problem in the procedure can consult. It will be pleasure for me to help you. I have done PhD on alkaloids. Sorry.\, due to the lack of time, I did not able to provide you complete details. But still I told you the total scheme. You can ask any question anytime. Thanks.

Thank you so much. This very thoughtful of you.