INFICON Explorer Portable Gas Chromatograph - Manual (Page 314)

Assay 2 User Notes
312
5. Column A analysis time is equal to 2.2 times the Column A backflush time.
Because Column A is also the precolumn, it must be backflushed for at least as
long as it was foreflushed.
6. Column B and C analysis times must meet two criteria; each must be long
enough to permit the last target peak to clear the column and the analysis time
must also be a minimum of 2.2 times the backflush time, for any given column.
If an analysis time is too short, for either of the above reasons, peaks may elute
during a later analysis.
NOTE: Explorer's maximum analysis time is 3200 seconds. If a peak elutes after this time
on any column, the method must be modified, increasing the temperature or
pressure will speed up heavy compounds.
7. Store all target compounds in the library, and calibrate on them using the new
method.
Example - Benzene and Toluene
If we are only interested in benzene at a concentration of approximately 0.5 ppm and
toluene at 0.5 ppm, we can customize the method provided.
To customize this method you will need to perform a run on Column B to determine
the exact elution time for each compound. You will then use this time to determine
the analysis and backflush times.
NOTE: To simplify this example we will assume there are no known interference
compounds.
Assuming an instrument with elution information as given previously, we will
modify the method as follows:
1. Using SiteChart, load the Assay 2 standard method.
Delete unwanted compounds from the library.
2. Disable Column B.