INFICON HAPSITE Smart Plus Chemical Identification System - Manual (Page 241)

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HAPSITE Smart Plus Operating Manual
Figure 6-6 Additional Calibration Points
Additional compounds are added by following the same steps.
CAUTION
The Reset Library function is used to delete all
calibration curves for all compounds and should only be
checked when this action is necessary.
6.3 Analyze (GC/MS) Methods
GC/MS is a reliable means of identifying volatile organic compounds. The sample
is drawn in through the probe or other sampling accessory. It is then passed
through the GC, where the sample is separated by boiling point and sent to the
Mass Spectrometer. Compounds are positively identified by GC retention time and
mass spectrum.
Analyze (GC/MS) Methods provide identification of compounds in two ways. By
extracting target mass ions from the MS response or as a result of searching the
total MS response against the AMDIS and/or NIST libraries. GC/MS Methods can
use Selected Ion Monitoring (SIM) or Full Scan MS modes. The sensitivity of an
Analyze (GC/MS) Loop method (full scan) will be in the approximate range of high
ppb to low ppm. The sensitivity of an Analyze (GC/MS) Concentrator method (full
scan) will be in the range from high ppt to low ppb. By comparison, a SIM method
will always give slightly improved sensitivity over a Sample Loop or Concentrator
method as these methods focus on a limited set of masses for detection. The
sensitivity is related to the compound and sampling system; the above are general
guidelines.