•Relating retention time tR to K (= Cs/CM)

•n = µ x fraction of time analyte is in mobile phase

•

•             moles of analyte in mobile phase

•n = µ x ---------------------------------------------

n                 number of moles of analyte

n

n                   CM VM                           1

nn = µ x -------------------- = µ x ---------------------

n             CM VM + Cs Vs           1 + CsVs/CMVM

n

nSubstituting  K = Cs/CM

n                                                   1

nGives                     n = µ x ------------------

n                                            1 + K Vs/VM