Showing posts written by Bob Bickler
For most chemists, flash purification is a means to an end. In other words, it is a tool needed to purify and isolate one compound from a mixture of compounds so that the next reaction can occur with ...
When developing reversed-phase flash chromatography methods it is important to understand the impact that a change in solvent ratio has on compound retention and, therefore, separation performance. Un...
Increasingly, organic and medicinal chemistry labs use mass-directed flash chromatography to isolate synthesized compounds. Mass-directed flash chromatography benefits are many, including collecting o...
Flash column chromatography is used by between 20 and 40 thousand organic synthesis chemists worldwide, an amazing number. For most of these chemists flash chromatography is an important part of their...
Higher performance flash columns are becoming all the rage these days. Chemists are using them for challenging as well as for routine purification. As a result, I am often asked, "do I need high-perfo...
An interesting question, at least to me. Depending on the detector brand, some mass spectrometer manufacturers recommend acetonitrile while others recommend methanol. Is there a real difference betwee...
As synthetic chemistry has evolved, so has flash chromatography. Target molecule synthesis is becoming more complicated and the synthetic products more polar. This shift in compound polarity has chang...
Acetone, as you know, is a terrific solvent. It dissolves many organic molecules, evaporates easily, is both water and organic soluble, and is cheap (relatively). These attributes tell me it should be...
I have previously posted on the topic of normal-phase optimization by evaluating different solvent blends or mixtures. I have also touched on reversed-phase method development as well suggesting chemi...
In previous posts I have discussed some options and techniques to improve detection of poorly absorbing or UV-transparent compounds – by wavelength focusing and by evaporative light-scattering (ELS).