While running blood samples you may need to make sure the Cogent Diamond Hydride™ HPLC column is to clean from run-to-run.
What can you do in terms of solvent washings to remove strongly retained materials from the column?
Answer: The first thing you can do is have a solvent wash step in your injection sequence. For example, every 10 injections or so you might have a solvent wash method to elute strongly adsorbed materials from the column. A good wash solvent to use for this purpose is 50/50 DI water/methanol or 50/50 DI water/isopropanol. After the wash method, the sample injections can resume.
Another approach is to incorporate the wash directly into the sample injection method itself. Your method could have solvent A as 50/50 DI water/methanol or 50/50 DI water/isopropanol. At the end of the gradient, you could go to 100%A and hold to elute materials from the column. In this manner, you can clean the column continuously in every run.
If you already have a method with a 100% aqueous A solvent, try substituting the 50% IPA or methanol and see how it works. The chromatography should not be drastically affected other than perhaps a slight shift in retention time.