INFICON Explorer Portable Gas Chromatograph - Manual (Page 315)

Explorer Operator Manual
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3. Ensure Explorer is setup and ready to run an analysis.
The instrument must be connected to carrier gas, and the instrument status must
show Ready.
4. Perform a few runs of your sample on Column A.
One peak should appear, this is the benzene/toluene co-elution at 150 seconds.
The peak must completely clear the column to ensure accurate quantitation.
This includes any peak tailing.
5. The backflush time must be set so that the compounds of interest clear Column
A before backflush begins.
You will use the retention time of the latest eluting peak to set the backflush
time. You cannot begin backflush until the benzene/toluene peak clears
Column A, so allow an additional 20 seconds. In this case the backflush time
should be set to approximately 170 seconds.
6. To set the analysis time use the retention time of the latest eluting peak and
multiply it by 1.1.
You will not know the exact time until you perform an analysis on Column B,
but should set the analysis time to at least 800 seconds to allow all peaks of
interest to elute.
7. Send the new method to Explorer and perform a run of your sample.
Two peaks should appear. The first peak will be the benzene. The next peak
will be toluene at approximately 410 seconds. The analysis time should be set
to the retention time of the last eluting peak multiplied by 1.1. In this example
450 seconds.
8. Perform a few more runs to ensure your timing is correct.
9. Remove all unwanted compounds from the Column B library.
10. Analysis and backflush time are critical method parameters. The existing
library information will become invalid. You must perform a run and store the
compounds in the library. If possible store each compound at more than one
concentration to obtain a more accurate calibration curve.
11. Perform a run and calibrate benzene and toluene in the Column B library.