Chromatography Forum

Hi! I was doing log D measurment using shake flask method. I did 1:1 octanol/h2O ratio, 1:2 oct:water ration and 1:4 octanol:water ration. All the compound went into octanol layer but my HPLC shows it not very lipophilic compound? seems like mid polar compound,then why all the compound went into octanol layer? I don't see anything in water layer et al. Even I directly injected the water layer without dilution.

How do I calculate log d now?

Try preparing saturated solution of your compound in octanol first.
Then try extracting it to as small as practically possible volume of water. Good luck!