Welcome to the Biotage Flash Purification Blogs.

    When should I use an amine-bonded silica for flash chromatography?

    May 8, 2020 at 8:30 PM / by Bob Bickler posted in Amine, Chromatography Fundamentals, Sfär, Media and Resin, Normal Phase

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    Flash chromatography is a standard part of an organic chemist’s workflow. It is utilized after most reaction steps in order to remove most of the generated by-products and excess reagents.

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    Does a longer flash column really provide better purification?

    April 17, 2020 at 9:30 PM / by Bob Bickler posted in Chromatography Fundamentals, Sfär, Scale-Up, Cost, Normal Phase

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    This is an interesting question that I am asked from time to time. There does seem to be two camps in which chemists reside – one believing longer and thinner columns provide better separations and the other preferring shorter and fatter columns to do the same chromatography.

    Which is right? That is a question I will try to answer based on my own data.

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    Understanding silica – why matching TLC and flash silica is important for good flash column chromatography

    April 15, 2020 at 12:00 PM / by Bob Bickler posted in Chromatography Fundamentals, Solvents, Sfär, Media and Resin, Normal Phase

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    Recently, I posted an article explaining why high performance TLC plates are not needed for method development for high-performance flash chromatography.  Based on some excellent feedback, I see a need to discuss silica chemistry and its impact on chromatography.

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    How do I remove an annoying MS TIC background?

    April 10, 2020 at 2:52 PM / by Bob Bickler posted in Chromatography Fundamentals, Troubleshooting and Optimization, Sfär, Detector, Normal Phase, V-10, Isolera

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    Have you ever run flash column chromatography with mass detection (Flash-MS) and observed the total ion current or TIC increase during the purification only to find that there was no discernible compound contributing to the effect?

    In this post I discuss how I came across this issue and the solution I found to work.

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    How does an alkaline pH affect normal-phase flash chromatography separations?

    April 7, 2020 at 6:25 PM / by Bob Bickler posted in Amine, Chromatography Fundamentals, Solvents, Sfär, Normal Phase, Isolera

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    The products of organic synthesis are designed with specific functional groups in order to possess desired properties. Depending on the compound’s functionality, it can be neutral, acidic, or basic as determined by a compound measurement called pKa or acid dissociation constant. Compounds with low pKa are typically acidic while those with high pKa tend to be basic. Compounds with a pKa near 7 are deemed neutral.

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    How does reversed-phase flash chromatography compare to prep HPLC?

    March 26, 2020 at 2:42 PM / by Bob Bickler posted in Reversed-phase, Green, Sfär, Selekt, HPLC

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    For medicinal chemists, maximizing the synthetic yield of their newly created intermediate compound is their priority. More times than not, flash chromatography is used to purify these intermediate compounds to at least 80% purity. Final compounds, however, not only require high yield but maximum attainable purity, typically in excess of 95%. For this purity level, chemists will either send the reaction mixture to an in-house prep HPLC lab or perform their own preparative HPLC compound purification, if it is available in the lab.

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    What is the Chemistry Behind Reversed-Phase Flash Chromatography?

    February 25, 2020 at 4:18 PM / by Bob Bickler posted in Chromatography Fundamentals, Reversed-phase, Sfär

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    In my previous post, I talked about the "Chemistry Behind Normal-phase Flash Chromatography", the most common form of liquid-solid chromatography. In this post, I focus on reversed-phase flash chromatography and how it differs from normal-phase.

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    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 Chromatography Fundamentals, Reversed-phase, Solvents, Sfär, Selekt, Media and Resin, Normal Phase

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    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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    Does Size Really Matter in Flash Chromatography? Part 2

    January 7, 2020 at 8:46 PM / by Bob Bickler posted in Chromatography Fundamentals, Sfär, Scale-Up, Normal Phase

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    In a previous post I talked about column size, specifically long-thin versus short-fat and the impact of the cartridge’s dimensions on purification performance. With that comparison I showed that in preparative chromatography, purification efficiency is more about the amount of silica than column dimensions. Cartridges of different dimensions containing the same amount of the same media will provide the same separation efficiency.

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    Pushing flash column chromatography loading limits

    December 30, 2019 at 3:39 PM / by Bob Bickler posted in Chromatography Fundamentals, Green, Sfär, Loading Techniques, Cost, Normal Phase, Pillar Page

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    A question I hear a lot from chemists is “how much can I load”. The answer is always “it depends on your separation quality”.  At that point I begin asking about the TLC data and purification goals. Purification goal setting should be your first step and the question to answer is – what do I need this purification to achieve? Is the goal high purity, high yield, or some combination.  Remember, you will typically sacrifice purity for high yield and yield for high purity so optimization is an important consideration.

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    Green Flash Chromatography Webinar

    November 26, 2019 at 9:03 PM / by Bob Bickler posted in Green, Sfär, Selekt, Webinar, Cost, Normal Phase

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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 many times can I reuse my flash chromatography column?

    November 21, 2019 at 3:40 PM / by Bob Bickler posted in Chromatography Fundamentals, Sfär, Cost, Normal Phase

    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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    Organic Chemistry Workflow – Typical Steps and Equipment

    November 12, 2019 at 3:04 PM / by Bob Bickler posted in Workflow, Sfär, Selekt, Loading Techniques, Normal Phase, V-10, Pillar Page, Initiator

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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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    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 Sfär, Selekt, Media and Resin, Loading Techniques

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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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    Biotage vs Biotage, and the winner is...

    October 23, 2019 at 9:28 AM / by Panagiotis Ioannidis posted in Sfär, Selekt, Cost, Isolera

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    When Isolera™ was launched, the maximum system pressure that could be reached was 10 bars, but reaching that pressure was a challenge since most of the Flash columns could not withstand the higher pressures. The maximum pressure rating for the Biotage® SNAP columns, for example, is limited to five or seven bars, depending on the size, and columns from most of manufacturers have the same limitation.

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    California State University Increases Productivity with Selekt

    October 22, 2019 at 3:07 PM / by Sarah Moran posted in Sfär, Selekt, Customer case, Cost

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    On a scenic drive up the I-15 in southern California, I got to take a tour of the undergraduate lab at California State University, San Marcos with Dr. Robert Iafe. His lab is one of the first to have the new Biotage® Selekt Flash Purification System paired with the Sfär columns. We discussed the impact on his undergraduates broadening capabilities to learn about new instruments, and how it has affected his own research in his goals to gain tenure at the university.

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