@pmpageni ...when your sample hardly dissolves in eluents, it's better to have dry loading where you can dissolve your compound in more polar solvents, add silica and evaporate the solvent. Compounds will be adsorbed in silica which you can load to column.
@vmelkon yes straight tube is ok but bulged column will have certain advantages as: 1) it can act as a reservior if you need to put large volume of solvent 2) while pouring solvent, it controls flow rate which prevents the disturbance of silica layer (as compared to straight tube) 3) it's easy to apply pressure (though gentle)...
@medchem90 ah ok that makes good sense. this is to increase its solubility in eluents when it is present as a hydrate or something? but you were using a steroid i thought
@medchem90 if it doesn't dissolve in your elutant, how do you expect it to move on your column? Wouldn't it be better to dissolve, load, then run your elutant and pull the junk off then run a gradient to the dissolving solvent and get your product off?
@ewbhockey sometime though your expected compound dissolves in eluents, impurities make it hard to dissolve the sample. In such case, it would be better to dissolve the sample completely in the appropriate solvent and try dry loading.
What is the motive behind dissolving silica in the sample?
pmpageni 1 month ago
@pmpageni ...when your sample hardly dissolves in eluents, it's better to have dry loading where you can dissolve your compound in more polar solvents, add silica and evaporate the solvent. Compounds will be adsorbed in silica which you can load to column.
medchem90 1 month ago
why is the top of the glass column bulged? I think any straight tube would do the job.
vmelkon 1 month ago
@vmelkon yes straight tube is ok but bulged column will have certain advantages as: 1) it can act as a reservior if you need to put large volume of solvent 2) while pouring solvent, it controls flow rate which prevents the disturbance of silica layer (as compared to straight tube) 3) it's easy to apply pressure (though gentle)...
medchem90 1 month ago
Thank you, I really need this help
lovelyriri24 3 months ago
what is the purpose of adsorbing your sample? why not just dissolve it in your eluate?
staratsx 4 months ago
@staratsx when your sample is hardly dissolved in eluents, its better to have dry loading (adsorb to silica and make it dry-to load)
medchem90 4 months ago
@medchem90 ah ok that makes good sense. this is to increase its solubility in eluents when it is present as a hydrate or something? but you were using a steroid i thought
staratsx 4 months ago
@medchem90 if it doesn't dissolve in your elutant, how do you expect it to move on your column? Wouldn't it be better to dissolve, load, then run your elutant and pull the junk off then run a gradient to the dissolving solvent and get your product off?
ewbhockey 1 month ago
@ewbhockey sometime though your expected compound dissolves in eluents, impurities make it hard to dissolve the sample. In such case, it would be better to dissolve the sample completely in the appropriate solvent and try dry loading.
medchem90 1 month ago
Thank you!
CuteJapandaBear 4 months ago
very good man ..but plz write the procedures in the video
saher018 7 months ago
why is the sand added as the first layer?
534Anthony 1 year ago
@534Anthony ..keeping sand after cotton wool will provide uniform base for stationary phase (silica) and at the same time prevents falling of silica.
medchem90 1 year ago
@medchem90
Thanks
534Anthony 1 year ago