36 Advanced User Guide
3 Inlets
Selecting parameters for the S/SL splitless mode
A successful splitless injection consists of these steps:
1 Vaporize the sample and solvent in a heated inlet.
2 Use a low flow and low oven temperature to create a
solvent-saturated zone at the head of the column.
3 Use this zone to trap and reconcentrate the sample at the
head of the column.
4 Wait until all, or at least most, of the sample has transferred
to the column. Then discard the remaining vapor in the
inlet—which is mostly solvent—by opening a purge valve. This
eliminates the long solvent tail that this vapor would
otherwise cause.
5 Raise the oven temperature to release the solvent and then
the sample from the head of the column.
Some experimentation is needed to refine the operating
conditions. Table 6 provides starting values for the critical
parameters.
Setting parameters for the S/SL splitless mode
Mode The current operating mode—splitless
Oven temperature Below solvent boiling point
Temperature Actual and setpoint inlet temperatures
Table 6 Splitless mode inlet parameters
Parameter Allowed setpoint range Suggested starting
value
Oven temperature 24 C to 425 C10 °C below solvent
boiling point
Oven initial time 0 to 999.9 minutes Inlet purge time
Inlet purge time 0 to 999.9 minutes 2 x Liner volume
Column flow
Gas saver time
*
* Gas saver is not supported on EPR (electronic pneumatics regulation) equipped GCs.
0 to 999.9 minutes After purge time
Gas saver flow 15 to 1000 mL/min 15 mL/min greater than
maximum column flow
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