Unformatted text preview: The average linear rate for the solute is:
v = L / tR
where L is the column length.
And for the mobile phase it is:
u = L /tR VR or tR
where VR = tR x flowrate This is simply the time required for a noninteracting substance to pass through the
column. v=uxf v =u f is the fraction of time that the solute spends in
the mobile phase.
=u Since both the mobile and stationary phases
have known volumes (VM, VS), we can now
determine K - our partition coefficient. 1 This shows the factors required to have a
component elute and how two materials can
Each material has its own K.
As K increases, elution takes longer.
Other terms affect the overall separation. ( =u f = n soluteM / n soluteS v=u( 1+KV /V )
CMVM +CMVS ( 1
1 1+ K VS
VS General increase in retention VM General decrease in retention u Increases speed of separation. VS and VM can be altered by changing column diameter
and length for a specific column packing.
u can be altered by changing the flowrate.
All terms can be found by knowing how the column was
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