How do I Choose the Right Column Size for Purification by Flash Chromatography?

In all my years of working with medicinal and organic chemists, I have found that choosing how many grams of silica to use for purification by flash chromatography is something frequently guessed at. Getting the size of the column right is awfully important because using too few grams of silica will doom your purification to failure and using more an optimal mass of the stationary phase means the purification  consumes excess silica, solvents, and a chemist’s time. To determine the optimal amount of silica for a purification, I rely on a factor called ΔCV (delta Column Volume) to identify the best loading capacity on any cartridge. I have also found that ΔCV this is a better loading capacity predictor for flash purification than ΔRf.

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How to Optimize TLC to Enhance Purification by Flash Chromatography

In this article I discuss the optimization of solvent ratios to generate ideal Rf (retention factor) values on TLC plates.  Then I show how maximizing efficiency of flash chromatography achieves higher loading with rapid and reliable isolation of compounds, reduced solvent use and improved separation. Continue reading How to Optimize TLC to Enhance Purification by Flash Chromatography

Using TLC to Scout Flash Chromatography Solvents

TLC is the tool most used for normal-phase flash chromatography method development. For many chemists, a solvent system of hexane (or heptane) + ethyl acetate is the first, and sometimes only, solvent system evaluated. Though often useful, ethyl acetate may not always provide the optimal purification conditions. Continue reading Using TLC to Scout Flash Chromatography Solvents

Why Reusing Flash Cartridges is Bad Science

For many chemists lab budgets, especially for consumable items, are limited.  One way of trying to stretch their lab budget is to reuse disposable flash chromatography cartridges.

In this post I will show how regardless of the cartridge brand used, repeated use of silica flash cartridges results in loss of compound resolution and fraction purity.

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Find Out Why The Era of Regular Flash Purification Has Come To An End

This article touches on the latest development in purification, ACI™ Accelerated Chromatographic Isolation, and how future needs of the typical Flash user will be met; way past the current limits of traditional flash. Flash evolved.

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Scaling up reversed Phase Flash Purification

Every chemist has been taught how to use and deal with glass columns in schools, so they have fundamental background experience. But unlike traditional normal phase flash, many chemists have little experience of dealing with reversed phase, and especially reversed phase flash. Continue reading Scaling up reversed Phase Flash Purification

The Lines Between Purification and Analysis are Blurring…

This article discusses two recent developments in flash purification that have increased cross-over with traditional HPLC techniques: cartridge media properties and new detectors in flash systems.

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