Welcome to the Biotage Flash Purification Blogs.

    How can I modify my flash chromatography method to separate chemically similar compounds?

    February 11, 2020 at 3:13 PM / by Bob Bickler posted in Gradient, Solvents, Troubleshooting, Media

    6 Comments

    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).

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    Why do I see more peaks than I expect with flash column chromatography?

    January 8, 2020 at 3:23 PM / by Bob Bickler posted in Chromatography, Gradient, Normal phase, Solvents, Troubleshooting

    0 Comments

    Are you observing more chromatographic peaks than you expect compared to TLC or other assessment data?  Well, it could be that your method is separating some isomers or, it could be that there is an actual method issue.

    In this post I will discuss what could cause a method issue and suggest some ideas as to how to fix it.

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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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    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

    4 Comments

    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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    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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    How does solvent choice impact flash column chromatography performance?

    October 18, 2019 at 9:44 PM / by Bob Bickler posted in Troubleshooting, Theory

    3 Comments

    Selectivity and solvent strength are the most important factors that determine success or failure of a chromatographic separation. These two independent dynamics apply to both normal- and reversed-phase chromatography and should be optimized, especially when high fraction purity is needed.

    In this post I will discuss the impact that elution solvent choice has on both normal- and reversed-phase purification.

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