Tag: flash column
How do particle size and flow rate affect normal-phase flash column chromatography?
Media particle size and solvent flow rate play major roles in chromatographic separations including flash purification. This is true in both reversed-phase chromatography (aka partition chromatography) as well as normal-phase chromatography.
The roles played are related to the overall compound mass-transfer kinetics and diffusion/dispersion as they migrate through the column. Smaller particles reduce sample dilution by reducing interstitial volume, while flow rate impacts the ability of molecules to efficiently pass through the porous particles.
In this post, I will show how both particle size and flow rate impact flash chromatography.
How can I make purification of hard-to-separate compounds greener?
The planet’s population is growing, its resources are dwindling – this is a problem. On top of that environmental contamination from myriad sources is only compounding the issue of available clean food and water.
As chemists, we contribute to this issue, to some degree, by performing reactions that generate chemical waste in the form of unwanted by-products and excess solvents from work-up and purification. What can we, as chemists, do to help reduce our so-called “carbon footprint”?
In this post, I discuss some ways to improve flash chromatography resource utilization, especially for hard separations.
Continue reading How can I make purification of hard-to-separate compounds greener?
How does solvent choice impact reversed-phase flash chromatography separations?
I have recently posted on how solvent choice influences the separation of hard to resolve compounds using normal-phase flash chromatography. As a chemist with an inquiring mind, I thought I would expand my research beyond normal-phase and see what happens in reversed-phase.
In this post, I share my results.
How to efficiently scale-up flash column chromatography
For synthesis and medicinal chemists, compounds are typically made only once en route to a final product. Once that compound shows activity toward a particular target, then the synthesis is scaled up meaning that purification too requires scaling. The same is true in natural product research where once a high-value compound is isolated at small scale, there is a need to isolate it at larger scale.
Both of these scenarios can be problematic to scale-up/ process chemists when other, non-chromatographic purification techniques are not successful. When this happens, either a different synthetic route or extraction process is needed or large scale chromatography is employed. In this post, I will explain how flash chromatography can be successfully scaled while minimizing time and solvent consumption. Continue reading How to efficiently scale-up flash column chromatography
Ionizable compound purification using reversed-phase flash column chromatography
With most chromatographic purifications, only two solvents are needed to adequately separate compounds from each other. Unfortunately, there are instances where the separation is either poor or cannot be accomplished with “normal” elution conditions such as those with ionic or very polar organic molecules.
In this post I offer some solutions to this issue.
Continue reading Ionizable compound purification using reversed-phase flash column chromatography
