If you are working with an analyte of MW ~10,000 or greater, you may observe no retention when using the 100A columns such as the Cogent Diamond Hydride™.
This is because the pores of an HPLC column account for most of the surface area of the phase and therefore interactions involved in retention. If an analyte is too large to fit into the pores, the retention interaction cannot take place. Hence, it will not be retained and will elute at the solvent front.
We do offer and suggest the Cogent Bidentate C8 300 Wide Pore 300A™ HPLC column, which is more suited to these types of analyses. Typically high molecular weight compounds will be proteins, polymers, and so on.