Can you have a capacity factor in HPLC

Question

I'm not sure if you can. The capacity factor is calculated for GC as the time it take the analyte to eluate minus the unretained compounds, divided by the unretained compounds. Would you get an unretained compounds in HPLC as the detector is chosen NOT to detect the solvent, the same way that GC does?

I'd apprecate anyone's help with this

Answer 1

Yes, you can certainly get unretained compounds off the HPLC.  Whether or not they are detected by the detector will depend on the nature of the compound and the nature of the detection.  For example, using electrochemical detection you can detect compounds that come off the column in the void volume if they are electrochemically active.  So, by your definition of capacity, I guess you could have this with HPLC.  It's really no different than GC.