Varying Oven Temperature; Varying Event Times; Vial Equilibration Time - Agilent Technologies G1289 Operating Manual

Varying Oven Temperature

The oven temperature can have a profound effect on the concentration of
analyte that passes into the headspace gas. In general, as the oven temperature
increases, the amount of gas entering the headspace from the sample
increases, increasing the pressure in the vial and delivering more analyte to the
GC. This increases the sensitivity of the analysis.
When you pick an oven temperature, consider the following:
•
•
There are two ways you can program the 7694 HS to increase oven temperature
in steps:
•
•
Note
Do not set the oven temperature within 10°C of the boiling point of any
solvents in the sample, except in special cases.
Note
Loop and transfer line temperatures should be set higher than the highest
temperature the oven will reach in a programmed sequence.

Varying Event Times

Vial Equilibration Time

The time that the sample vial spends in the oven determines the amount of
analyte in the headspace gas and the presence or absence of equilibrium. The
7694 HS can be programmed to analyze a series of samples to determine if
equilibrium is reached.
Over-pressurization of the headspace vial could be dangerous.
Unstable compounds could degrade at elevated temperatures.
Use Chain Methods (see "Chaining Methods" on page 65) and setting the
oven temperature higher in each method in the chain
Use Param Increment (see "Advanced Function Descriptions" on
page 44).
Developing Methods
Varying Oven Temperature
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