Welcome to the Biotage Flash Purification Blogs.

      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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      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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      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

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      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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      How important is your flash column’s plate count, aka efficiency, to your purification?

      October 29, 2019 at 5:00 PM / by Bob Bickler posted in Optimization, Media

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      Plate count is a theoretical number describing the separation efficiency of a chromatography column. In short, it is a measure an eluting compound's bandwidth at the time it elutes from a column, Equation 1.

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      Which sorbents work best for dry loading flash column chromatography samples?

      October 18, 2019 at 10:05 PM / by Bob Bickler posted in Solvents, Media, Loading method

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      For chemists needing to purify natural product extracts or synthesis reaction mixtures flash chromatography is typically the tool of choice. In previous posts I have discussed various ways to optimize the purification to obtain the highest purity compounds with maximum load in minimal time.

      Sometimes, though, chemistry gets in the way in the form of solubility issues. When this happens most often dry loading is recommended for these sample types. In this post I will show the impact various dry load sorbent options have on chromatography.

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      Six key factors that impact flash chromatography

      October 18, 2019 at 9:54 PM / by Bob Bickler posted in Optimization, Solvents, Media

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      In this post I will delve into six key factors that impact your purification success in flash column chromatography.

      Previously, I have discussed the use of TLC for solvent scouting and method development and optimization. I have have also talked about cartridge size, particle size, and surface area and their impact on flash purification.  Here I integrate that information into the six factors below.

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      How does solvent choice impact reversed-phase flash chromatography separations?

      October 4, 2019 at 6:30 PM / by Bob Bickler posted in Cannabis, Chromatography, Gradient, Normal phase, Optimization, SNAP, Solvents, Troubleshooting, Selekt, Media, Mass-directed purification, Theory

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      I have recently posted on how solvent choice influences the separation of hard to resolve compounds using normal-phase flash chromatography. As a chemist with an inquiring mind, I thought I would expand my research beyond normal-phase and see what happens in reversed-phase.

      In this post, I share my results. 

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      When should I use dry loading instead of liquid loading with flash column chromatography?

      October 4, 2019 at 6:17 PM / by Bob Bickler posted in Chromatography, Small Molecule, Polar, Samplet(R), Synthesis, Workflow, Media, Loading method

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      Many microwave assisted organic synthesis (MAOS) reactions use polar solvents such as alcohols, DMF, DMSO, because they absorb and transfer microwave energy very efficiently.  However, the downside of using polar, microwave absorbing solvents is that they can interfere with normal-phase flash chromatography.

      In this post, I discuss why dry loading can be advantageous when purifying polar-solvated reaction mixtures.

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      How to minimize particulate build-up in flash chromatography systems

      July 9, 2019 at 3:23 PM / by Bob Bickler posted in Optimization, Media

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      In order to perform flash chromatography consistently, the equipment you use must be properly maintained by following some “best practices”. These best practices include using clean solvents (I typically use ACS grade), volatile organic modifiers, and quality columns.

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      How changing stationary phase chemistry can impact separation selectivity

      June 12, 2019 at 2:42 AM / by Bob Bickler posted in Optimization, Media

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      Challenging separations, we all have faced this vexing problem. You synthesized your compound, analyzed it, and know your molecule is in there, based on LC-MS or TLC. Then, you do some method development using a silica TLC plate and see a major spot with some minor, early-eluting impurities. You think that the purification will be easy only to find that your “purified” compound has some co-eluting impurities. Now what? Should you change solvents or change stationary phase?

      In this post, I will show how changing the column media but keeping the same solvents removed a co-eluting impurity in one of my reaction mixes.

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      How many ways can you load sample on your column?

      May 31, 2019 at 4:02 PM / by Raffaella Bombarda posted in Chromatography, Samplet(R), Sfär, Media, Loading method

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      Biotage®, a pioneer in Flash Purification, launched the unique, removable cap SNAP flash chromatography columns in 2007. This beneficial column design feature continues with the newest Biotage flash columns named Sfär columns.

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      Dry loading media options – diatomaceous earth

      May 28, 2019 at 10:47 PM / by Bob Bickler posted in Media, Loading method

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      Various flash chromatography sample loading options are available including liquid and dry loading. Choosing the right technique is important because your sample loading choices (sample solvent and dry load sorbent), can have a major impact on the results.

      In this post, I compare the two techniques and show the benefits dry loading with a form of diatomaceous earth can bring to your purification.

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      Can reversed-phase flash chromatography purify better than normal-phase?

      May 9, 2019 at 4:44 PM / by Bob Bickler posted in Normal phase, Reversed-phase, Media

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      The answer to this question is yes, reversed-phase can sometimes provide a better separation and thus better purification than normal-phase.  When is reversed-phase likely to be the better choice is a different, and likely better, question.

      In this post I will try to demonstrate when reversed-phase is likely the better purification mode.

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      How do particle size and flow rate affect normal-phase flash column chromatography

      May 7, 2019 at 5:19 PM / by Bob Bickler posted in Chromatography, Media

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      Media particle size and solvent flow rate play major roles in chromatographic separations including flash purification.  This is true in both reversed-phase chromatography (aka partition chromatography) as well as normal-phase chromatography. The roles played are related to the overall compound mass-transfer kinetics and diffusion/dispersion as they migrate through the column.  Smaller particles reduce sample dilution by reducing interstitial volume, while flow rate impacts the ability of molecules to efficiently pass through the porous particles. In this post, I will show how both particle size and flow rate impact flash chromatography.

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      Greener flash chromatography tips

      April 30, 2019 at 10:18 PM / by Bob Bickler posted in Chromatography, Solvents, Media

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      In our more environmentally aware climate, chemical and pharmaceutical companies now prioritize reducing organic solvent use in chemistry labs. Employees and shareholders alike are pushing their companies to become greener which impacts how chemistry, both synthesis and purification, is performed.

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