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 the flash chromatography that follows it injected directly onto a flash cartridge.
In this post, I discuss why dry loading can be advantageous when purifying polar-solvated reaction mixtures.
Continue reading When should I use dry loading instead of liquid loading with flash column chromatography?
Increasingly, organic and medicinal chemistry labs use mass-directed flash chromatography to isolate synthesized compounds. Mass-directed flash chromatography benefits are many, including collecting only the targeted molecule(s) in the reaction mixture. This approach simplifies compound purification since you know what you have made and it’s associated mass.
However, there are mass detection nuances that can be challenging. One of these is to know when an acid should be added to the mass detector’s make-up solvent to protonate targeted molecules. In this post, I will provide some insight on this topic.
Continue reading When should I add acid to my detector make-up solvent when using mass-directed flash chromatography?
In this post, I will look at the impact modifying mobile phase pH can have on reversed-phase separations.
Continue reading Using pH to optimize reversed-phase flash chromatography separations
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.
Continue reading How do I remove an annoying MS TIC background?