Welcome to the Biotage Flash Purification Blogs.

      Green Flash Chromatography Webinar

      November 26, 2019 at 9:03 PM / by Bob Bickler posted in Chromatography, Webinar

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      Over the past several decades, the chemical industry has implemented process changes and updated practices in R&D and manufacturing in an effort to reduce liquid and solid lab waste. The pharmaceutical industry in particular has taken steps within their drug discovery labs to reduce solvent use by requiring their chemists to find and implement measures that achieve the corporate environmental goals without curtailing their productivity – quite the challenge.

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      How do I purify ionizable organic amine compounds using flash column chromatography?

      November 21, 2019 at 3:59 PM / by Bob Bickler posted in Amine, Chromatography, Gradient, Normal phase, Optimization, Polar, Solvents, Troubleshooting, TLC

      4 Comments

      For most organic reaction mixture purifications the process is fairly straightforward. Use hexane/ethyl acetate or, for polar compounds, DCM/MeOH.  But what do you do if this doesn't work and your compounds are basic organic amines?

      In this post, I re-examine the options available to achieve an acceptable organic amine purification when typical separation methods are insufficient.

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      Does particle shape and/or particle size impact flash column chromatography load limits?

      November 21, 2019 at 3:51 PM / by Bob Bickler posted in Media

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      There are many factors which influence successful flash column chromatography. One of those factors is sample load, which itself is influenced by things like selectivity, efficiency, dissolution solvent, and load technique. Several of these factors I have addressed in previous posts. Of these, selectivity and efficiency are specific to a media's physical and chemical characteristics.

      In this post I will show if particle size and/or particle shape can influence loading capacity.  Additionally, I will show the positive impact that surface area has on flash column chromatography purification.

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      Why can’t I reproduce my TLC separation using flash column chromatography?

      November 21, 2019 at 3:48 PM / by Bob Bickler posted in Optimization, TLC

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      You have performed your synthesis and now it is time to purify the reaction mix. You have used thin-layer chromatography (TLC) and see a separation but when you try to purify with flash column chromatography, you can’t get the target compound separated from an impurity. So, what is happening (or isn’t happening)?

      In this post I will give some input on why some separations are not transferable from TLC.

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      How does mobile phase organic solvent choice impact reversed-phase flash column chromatography?

      November 21, 2019 at 3:45 PM / by Bob Bickler posted in Gradient, Optimization, Polar, Solvents, TLC

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      Organic and medicinal chemists frequently utilize flash chromatography to purify their reaction mixtures. Normal-phase flash chromatography is most often used but may not the best methodology, especially when the compounds are quite polar and/or ionizable.

      For these molecules, reversed-phase flash chromatography is preferred but often is not used due to an uncertainty regarding the best solvent choices and the reversed-phase mechanism.  In this post, I will discuss how organic solvent choice in reversed-phase chromatography can influence the chromatographic separation.

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      How many times can I reuse my flash chromatography column?

      November 21, 2019 at 3:40 PM / by Bob Bickler posted in Gradient, Normal phase, Optimization, Polar, Solvents, Troubleshooting

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      Flash chromatography – a purification tool for both organic chemists and natural product researchers.  This tool is essential when you need to remove impurities from your targeted product, or products, in order to get them pure.  To reduce the costs associated with flash chromatography, some chemists try reusing the same column over and over, not always with success.

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      How Much Is My Flash Chromatography System Really Going to Cost?

      November 15, 2019 at 3:01 PM / by John Urh posted in Chromatography, HPLC, Media

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      This, of course, is always one of the first questions an organic, medicinal, or peptide chemist has when starting the research process for a flash chromatography system. Here at Biotage, we receive this question hundreds and hundreds of times a year, likely within the first couple of minutes of any conversation.

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      Organic Chemistry Workflow – Typical Steps and Equipment

      November 12, 2019 at 3:04 PM / by Bob Bickler posted in Chromatography, Synthesis, Workflow

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      Synthetic organic chemistry is the genesis of new pharmaceutical and commercial chemical products. In short, it is based on the idea that two or more carbon-based compounds can be forced to react using heat, or other energy source, to create a new, novel product – but this we already know.

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      The Step Gradient Explained

      November 1, 2019 at 9:37 PM / by Greg Saunders posted in Gradient, Selekt

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      Up to six compounds can be easily separated with an automated step-gradient optimizer embedded in modern flash chromatography systems.

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      How to prevent compound precipitation during flash column chromatography

      November 1, 2019 at 9:34 PM / by Bob Bickler posted in Peptides, Solvents

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      Compounds precipitating during flash chromatography is at best an inconvenience when working up your crude reaction mixture.  Precipitation during purification typically happens in the column or in the tubing exiting the column.

      In this post, I will propose a strategy that can minimize and perhaps prevent this issue from occurring.

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      What is the optimal sample to sorbent ratio for dry loading in flash column chromatography?

      November 1, 2019 at 9:32 PM / by Bob Bickler posted in Media, Loading method

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      For chemists preferring or needing to dry load their crude sample mixtures to get an acceptable flash purification result, using the right ratio of sample to sorbent can be quite important.  Too much sample and solubility issues can ensue, too little sample and significant band broadening occurs, reducing the separation quality.

      In this post, I propose an acceptable ratio range based on my own experimental data.

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      Flash column equilibration – is it a waste of time or necessary step?

      November 1, 2019 at 9:30 PM / by Bob Bickler posted in Optimization, Media, Theory

      2 Comments

      slash column chromatography has been practiced by chemists since the 1970s. That practice requires the silica in the column be properly wetted to remove trapped gasses and ensure uniform flow (remember those days of not letting air into the column?). Today, with automated flash chromatography systems and pre-packed columns as the norm, chemists ask me – do I really need to pre-equilibrate my column?

      In this post I explore the impact on chromatography that equilibration, and lack thereof, has on separation performance.

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      Why are my flash column chromatography peaks splitting?

      November 1, 2019 at 9:19 PM / by Bob Bickler posted in Troubleshooting

      2 Comments

      Split peaks? Multiple peaks? Are they really a problem? What causes the issue?

      In this post I will discuss what split peaks are and what to do to fix the problem.

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