INFICON Explorer Portable Gas Chromatograph - Manual (Page 300)

Assay 1 User Notes
298
Vinyl chloride and chloromethane elute at about 60 seconds on Column A. The
backflush time for the second run on Column C can be set to 70 seconds, this allows
vinyl chloride and chloromethane to clear the precolumn (Column A). Benzene is
still in Column A when backflush begins. Column C elution time for chloromethane
is about 135 seconds and about 150 seconds for vinyl chloride. Analysis time on
Column C will be about 3 minutes.
This new method provides an analysis time of 9 minutes, a time saving of
approximately 4 minutes.
NOTE: The retention time values provided here are for illustration purposes only.
You must perform runs on both Column A and C to determine the exact retention
times. These values must be determined experimentally before you can modify the
method on your instrument.
To setup your instrument with this method:
1. Using the SiteChart software, load the Assay 1 standard method.
Delete unwanted compounds from all three libraries.
2. On SiteChart’s Assay tab, select Column A and set the analysis time to 270
seconds and the backflush time to 120 seconds.
This provides 150 seconds for backflushing the precolumn.
3. On the Assay tab, select Column C and set the analysis time to 170 seconds
and the backflush time to 70 seconds.
4. Save the new method under a new .app filename, and send it to Explorer.
5. On Explorer, enable Columns A and C.
6. In SiteChart, select Column A and perform a run.
This run will give two peaks. The first peak is the vinyl chloride/chloromethane
co-elution at about 60 seconds, the other peak is benzene at 102 seconds. You
will need to calibrate benzene on Column A.