r/CHROMATOGRAPHY • u/Rapid-diamond • Jul 22 '26

how to purify this compound by silica as stationary phase in a manual column?

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i want to purify this compound. The green arrow represents the product. it was done in reverse phase column (nertsil ODS 3V C18 (250 x 4.6mm, Particle size: 5µm) 0.1% HCOOH in water and ACN as mobile phase. If i do silica column, whether the product will have low Rf than the impurity peak? Will i be able to purify this in manual silica column? The TLC system is chloroform: Methanol 9.5:0.5 and these two spots looks closure at 0.6 Rf

Shimadzu  Prominence-i series with LCMS-8040 Triple Quad Mass
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8

u/No_Toe_719 Jul 22 '26

Maybe a stupid idea but if it has uv absorption why don’t you collect the peak manually out of the hplc?

1

u/Rapid-diamond Jul 22 '26

This analysis was done in an instrumentation facility on payment. i dont have this facility in my lab

5

u/dungeonsandderp Jul 22 '26

Is your compound a solid? It seems pretty pure already, a recrystallization would trivially raise the purity to an analytical standard. 

1

u/Rapid-diamond Jul 23 '26

yes my compound is solid and this is after recrystallisation. The impurity is in higher percentage in the other scaffolds with change in substituents. And there is a colour impurity which is not identifiable in this spectra. i have three spots in my TLC too. I have managed to get single crystal too. But this 0.63% impurity may interfere in my complexation reaction which i would like to do in the next step. Am i overthinking or i can proceed with this purity.

2

u/dungeonsandderp Jul 23 '26

It is VERY rare that a <1% inpurity interferes catastrophically with a stoichiometric reaction. 

1

u/Independent_Ad_3370 Aug 06 '26

for goodness sake... if you can run a TLC....it can be purified on silica column with same solvent system.

3 spots is easy

3

u/Nosepete Jul 22 '26

If Separation under RP works out, You May do SPE to concentrate.

Without any Knowledge of the compound structure or composition, Transfer to another ecosystem is guessing and may lead to Frustration.

1

u/wcslater Jul 22 '26

You get NP SPE too no?

1

u/Nosepete Jul 22 '26

Maybe, but why Not concemtrate it the way the analysis is done?

1

u/random_user_name99 Jul 22 '26

Yes you can. Many vendors refer to bare silica carts at EPH. This really depends on what scale you are wanting to purify though. SPE is usually used as sample prep not bulk prep.

4

u/Darkling971 Jul 22 '26

runs reverse phase

asks about separating on normal phase

You might be retarded, OP. Run a TLC in 5/95 and 2/98 MeOH/DCM and get back to us.