In my role as senior technical specialist at Biotage I am often asked about compound detection options. For most flash chromatography methods, UV is the default detection tool since a majority of compounds do absorb some UV light.
Diode array UV detectors provide chemists choices in wavelength selection, providing the ability to widen or narrow the wavelength range needed to detect specific compounds and enhance their sensitivity.
When diode array detectors fail to detect compounds, it is because the compounds have no chromophore, e.g. carbohydrates, low extinction coefficients, exist in really low concentrations, or any combination of these. In these situations, alternative detectors are quite beneficial. In this post I will discuss a couple of detector options for flash chromatography.
Continue reading So, which detector should I use for flash column chromatography?
The bane of organic synthesis for most chemists is purification rather than synthesis. Synthetic reaction mixtures are rarely devoid of impurities so some type of purification is necessary. Most often flash chromatography is used but for many chemists, it is less well understood than their chemical reaction and provides some level of anxiety.
In this post, I will summarize the five most important steps to creating a successful flash chromatography method and thus the anxiety associated with it.
Continue reading 5 Steps to successful flash chromatography
The challenges organic, medicinal, and natural product chemists face are many: from designing reactions, to optimizing synthesis, work-up / extraction, and purification / isolation of the desired compound or compounds. Among those issues related to purification / isolation is the common problem of separating compounds with similar chemistry that either co-elute or separate poorly.
In this post I will discuss some tips on how to “resolve” this issue (yes, pun intended).
Continue reading How can I modify my flash chromatography method to separate chemically similar compounds?
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