Ideal solvents & conditions

[phenolholic]

A FOAF wants to know ideal conditions/solvents for educational purposes. Think outside of Home-Depot and household solvents. FOAF has accessibility to research-grade solvents.

First, in acidic bath, what is the optimal pH?
Second, for defatting, what is the ideal solvent?
Third, for basic bath, what is the ideal pH?
Fourth, what is the ideal nonpolar solvent to extract from basic aqueous solution?
Fifth, what is the ideal solvent/method for recrystallization?

Please don't limit FOAF's choices from what's readily available or alternatives.

 

[burnt]

First, in acidic bath, what is the optimal pH?

2-3. recommend glacial acetic acid.

Second, for defatting, what is the ideal solvent?

hexane

Third, for basic bath, what is the ideal pH?

12-13

Fourth, what is the ideal nonpolar solvent to extract from basic aqueous solution?

hexane will work preferably warm. diethylether works. petroleum ether works. toluene works but not recommended unless you have a rotovap to dry it all off. dont use chloroform or dichloromethane (artifacts can form). also there has been discussion of using d-limonene which also dissolves spice very well.

Fifth, what is the ideal solvent/method for recrystallization?

hexane by far. method after evaping off non polar solvent (if its not hexane, if you used hexane just concentrate it and freeze) add warm hexane small amounts just until the dmt dissolves then put in fridge then freezer.

success!

 

[phenolholic]

Thanks. Seems hexane reigns supreme for everything. A FOAF mentioned something along the lines of trying the ideal solvent/condition discussed for immediate extraction, and will later perform a thorough qualitative assay of varying solvents and conditions in each step, to arrive to the most pure & greatest yield. Stay tuned

 

[phenolholic]

hexane will work preferably warm. diethylether works. petroleum ether works. toluene works but not recommended unless you have a rotovap to dry it all off. dont use chloroform or dichloromethane (artifacts can form). also there has been discussion of using d-limonene which also dissolves spice very well.

So which is the best?

 

[burnt]

that depends on the purity of the compound you are seeking. to get the cleanest crystals use hexane