User`s guide

Method Development
231
NOTE: Superior performance is always obtained, even at the
expense of a small outlet split ratio, by increasing the
velocity of the carrier gas through the trap during
secondary desorption.
During primary desorption:
Flow Through the Tube = Flow Through the Cold Trap Equation 1
During secondary desorption:
Flow Through the Heated Trap = Outlet Split Flow + Column Flow
Equation 2
NOTE: The column flow must be measured at the column outlet
during secondary desorption.
The fraction of sample from the tube that reaches the analytical
column and the detector:
Equation 3
The percentage of components from the sample tube reaching the
GC detector:
Equation 4
Example: You want 20% of the tube sample to reach the GC
detector. The column flow rate is 2 mL/min (measured during
secondary desorption). Trap desorb flow is 10 mL/min and there
is no inlet split flow.
Column Flow Rate
Heated Trap Flow Rate
--------------------------------------------------------
% of Components Reaching the Detector
Column Flow
Column Flow + Outlet Split Flow
---------------------------------------------------------------------------------
100×=
SplitOutlet 2
ml/min 2
20%
+
=