Flash chromatography is often run using default gradients built into the flash chromatography system. This usually produces a reasonable purification with minimal work on method development. When running normal phase, these gradients typically start at 0% B (the strong solvent). Reverse phase gradients start at 5% to 10% B to avoid phase collapse, and so will not be discussed here. Most compounds elute well with the standard gradients. Compounds that need only a small concentration of B solvent, however, will often elute later than expected, and may elute together.
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How Much Money Is Really Being Saved (or Lost) by Reusing Silica Flash Columns?
June 2, 2021
In our testing of the impact of strong solvents on the reproducibility of runs on analytical HPLC silica columns[1] we found a significant amount of wash is required for the column to behave as it did prior to first running a strong solvent on it. Surprised by how much solvent was needed, a conversation began among those of us in the Applications lab regarding this same effect on flash silica columns and the true cost of trying to reuse them.
How can you keep your ELSD performing optimally?
May 7, 2021
One of the unique offerings for Teledyne ISCO flash prep and chromatography systems, including CombiFlash NextGen, EZ Prep and ACCQPrep, is the ability to add an internal evaporative light scattering detector (ELSD) without increasing the footprint of the instrument. ELSD is a great secondary detection method for compounds lacking UV chromophores. Our ELSD customers really like this feature and one question they often ask is, how do we keep the ELSD performing like new?
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Do you really want to switch solvent systems on RediSep Prep HPLC Silica columns?
March 11, 2021
Normal phase separations using silica columns are common in flash separations, but the columns are traditionally one-time use and are used with a single solvent system.
Matching Aromatic Solvents with Aromatic Compounds
for Flash Chromatography
February 25, 2021
As chemists we are fortunate that automated flash purification is so forgiving. The gradient nature of running the common hexane/ethyl acetate solvent system from 0 to 100% gives us many first-time successes.
Keep Silica Out of your Bump Trap: Solid Sample Loading Made Easier!
February 11, 2021
Solid sample loading is a great way to perform more efficient and consistent flash chromatography. With solid loading you can eliminate the effects of injection volume and solvent on your chromatography.
Rapidly Create Focused Gradient Methods for Prep LC from Analytical Scouting Runs
January 25, 2021
Which standard operating procedure in a preparative chromatography lab is more efficient: routinely running generic full-range gradients to purify mixtures, or taking the extra time and trouble to develop focused gradient methods?
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How to Queue Up Samples to Run Automatically
January 25, 2021
One of the most popular features of the ACCQPrep, when connected to an autosampler, is the ability to create a queue of samples to be run automatically—great for walk up environments and for labs running many different samples on a regular basis, often unattended overnight.
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Methods for Extending the Life of Your Prep Columns
January 22, 2021
Open-access systems provide many advantages, but an important disadvantage is the increased potential for improper column use and care. Prep labs need to be alert to the impact of injecting samples that are not properly prepared, or are dissolved in viscous solvents such as DMSO.
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Back to Basics: How to Run TLC Plates Properly!
January 22, 2021
One way to more rapidly develop an optimal flash purification method is to first run the target compound using thin layer chromatography (TLC) with different mobile phase compositions.
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Welcome to the New “Sharper Peaks Ahead” Chromatography Blog
January 21, 2021
As one of the authors of our new chromatography blog, I wanted to take this chance to introduce myself. I’m Josh Lovell, one of the Application Specialists at Teledyne ISCO, and along with my colleagues Jack Silver and Todd Anderson, we would like to welcome you to “Sharper Peaks Ahead,” a blog dedicated to sharing insights into faster, more efficient, and higher resolution chromatography.
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