will large volume DMSO hurt my preparative scale column

[moon704520]

my sample not easy to dissolve ,a lot of DMSO was used,but will large volume DMSO hurt my preparative scale column
many thanks

[HUH?]

The greatest danger with using large amounts of DMSO is the change of viscosity. DMSO, when added in a large volume can cause a pressure spike. Most HPLC systems use a "make or break" injection valve to reduce or eliminate a pressure "slam" on your prep column at injection. Sending a large volume of DMSO onto your prep column can mimic this pressure "slam" which could potentially compress your prep column's bed. If you simply reduce the flow rate during injection, you will reduce or eliminate this potentially damaging pressure spike during injection.
The next greatest danger to your column is when your mobile phase dilutes your DMSO dissolved sample to the point of precipitation. If your sample is not very soluble in the eluting solvent, it may precipitate in your tubing or on the column and displace the column's solid phase packing, creating a void. The best practice is to find a more appropriate dissolving solvent. You can use slight warming, sonication, and vortexing to aid in dissolution. You can also adjust pH. Finally, use some tricks like dissolving your sample in a very small volume of your eluting organic solvent. You can then add the aqueous eluting solvent until you approach or reach your initial condition composition. You have to be willing to experiment to discover what will work in each case. Failure means some recovery, but your sample will remain intact. Good luck

[Uwe Neue]

A well designed column does not have a problem with a DMSO injection. I have also worked with samples that precipitate, and once again, this may clog your column and require that you redissolve the sample at a slow flow rate, but a well-designed column does not suffer from this.

If the column is not well designed or badly packed, it will suffer from DMSO injections.