We are trying to purify a compound through preparative HPLC/Flash chromatography at larger volumes (KG level), as it is very less soluble in any solvent we are facing volume overload problem. If we try solid loading in flash chromatography, is that the right choice for such kind of compounds?
Dear Balu, The use of solid load cartridges provide the best resolution for purifying
compounds, although it does require an extra drying step to prepare the
sample. The extra time required to prepare the sample can be recovered from
increased loading or improved purity. Solid load cartridges can be used with
C18 columns with the use of C18 solid load cartridges or celite.
Liquid loading allows fast sample loading but with reduced resolution. The
strong solvent tends to wash the compound through the column, reducing
interaction with the stationary phase. Liquid loading is useful when there is
a great deal of resolution between compounds. A Sample Load Pump allows
easier loading, especially with C18 columns with their high backpressure.
For flash chromatography, solid loading often gives the best resolution. Unfortunately, it won't work for HPLC.
Here are some useful references- one discusses different loading techniques for silica columns, the other discusses different loading techniques for C18. For C18 flash, I've had some luck dissolving the sample in DMSO. My experience is that DMSO sometimes acts as a strong solvent causing reduced resolution and sometimes peak splitting, but it is still useful in many cases.
This compares and contrasts loading techniques (liquid injection, different types of solid load) for silica. Although written for use with an automated flash system, the information is useful for any flash column: http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN29_Overview_of_Silica_Column_Sample_Loading_Techniques.pdf
This is the same information for C18. I found that peptides seem to be an exception, and seem to work better as liquid load in the weakest possible solvent: http://www.isco.com/WebProductFiles/Applications/101/Application_Notes/AN88_C18_Flash_Column_Loading.pdf
Dear Balu, The use of solid load cartridges provide the best resolution for purifying
compounds, although it does require an extra drying step to prepare the
sample. The extra time required to prepare the sample can be recovered from
increased loading or improved purity. Solid load cartridges can be used with
C18 columns with the use of C18 solid load cartridges or celite.
Liquid loading allows fast sample loading but with reduced resolution. The
strong solvent tends to wash the compound through the column, reducing
interaction with the stationary phase. Liquid loading is useful when there is
a great deal of resolution between compounds. A Sample Load Pump allows
easier loading, especially with C18 columns with their high backpressure.
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