Welcome to the Biotage Flash Purification Blogs.

      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 dry load, silica, media

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

      October 18, 2019 at 10:05 PM / by Bob Bickler posted in dry load, solvent, media

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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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      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 cartridge, Celite, chromatography, DCM, Developments, DMF, dry load, MAOS, microwave, polar, Samplet(R), silica, synthesis, workflow

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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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      Preparation and use of an internal dry loading device for flash chromatography

      September 17, 2019 at 2:15 PM / by Bob Bickler posted in dry load, loading method, liquid load

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      Your choice of sample loading technique can, and likely will, affect the separation and purity of your targeted compound. While liquid loading is easy and often fit for purpose, it can provide some issues especially if large sample volumes are required relative to column size (> 1% of a column volume) or the dissolution solvent is too strong for the chosen purification method (e.g. injecting a methanol-solvated sample into a hexane/ethyl acetate mobile phase).

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      What are good reversed-phase dry load options?

      July 23, 2019 at 2:40 PM / by Bob Bickler posted in dry load, reversed-phase, sfär

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      Using a “dry” loading technique with flash chromatography typically improves compound purity and overall separation quality compared to liquid loading. The reasons for this I have prophesized previously and include:

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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 dry load, samplet, Samplet(R), flash chromatography, Flash column chromatography, column, silica column, flash purification, sfär, loading capacity

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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 dry load, diatomaceous earth

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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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      Which dry load sorbent should I use for flash column chromatography?

      February 19, 2019 at 10:55 PM / by Bob Bickler posted in dry load, silica, media, sorbent

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      This is an interesting question that does not have a straightforward answer. In fact, there are many materials that are potentially useful sorbents for dry loading crude mixtures. Some of the more popular are silica, diatomaceous earth (e.g. ISOLUTE® HM-N, Celite®), alumina, and Florisil®. The sorbent choice can influence your purification results because each of the available media have different chemistry and capacity. In most cases, sample/sorbent reactivity really is not a major concern, though it can occur. What is important is the sorbent’s capacity to adsorb/absorb all of your sample and the ratio of your crude sample to the amount of dry load sorbent.

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      Does your crude sample/sorbent dry load ratio impact flash column chromatography results?

      February 5, 2019 at 8:10 PM / by Bob Bickler posted in dry load, silica, Flash column chromatography, sfär, Selekt

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      Dry loading crude samples for flash purification typically works better than liquid loading, especially for challenging purifications. In this post, I discuss how the ratio of crude sample to dry load sorbent impacts purification performance.

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