INFICON Explorer Portable Gas Chromatograph - Manual (Page 298)

Assay 1 User Notes
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3. 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.
4. 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.
5. Store all target compounds in the library, and calibrate on them using the new
method.
Example - Benzene, Vinyl Chloride and Chloromethane
The following examples use three compounds that can be separated using different
methods. Our compounds of interest are benzene, vinyl chloride and chloromethane.
To simplify this example we will assume there are no known interference
compounds.
In these examples, we will assume that the instrument we are customizing provides
the typical retention times listed in the tables below.
Solution 1 - Single Run with Analysis Time = 13 Minutes
In this example we are looking for a method to separate benzene, vinyl chloride and
chloromethane in a single analysis.
The analysis time required, determined by benzene’s retention time, will be about 13
minutes. A modified method can be set up as follows:
1. Disable columns A and B.
You must do this on
Explorer.