INFICON HAPSITE Smart Plus Chemical Identification System - Manual (Page 439)

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HAPSITE Smart Plus Operating Manual
Chapter 13
Headspace Sampling System
13.1 Introduction
The Headspace Sampling System (HSS) is an accessory to the HAPSITE portable
GC/MS, allowing testing for volatile compounds in various solid and liquid matrices,
including soil and water. Used in combination with the HAPSITE, the Headspace
Sampling System attachment provides the opportunity to perform soil and water
analyses for quantitative and qualitative results in the field. See
Figure 13-1 .
Figure 13-1 Headspace Sampling System
The HAPSITE is designed to analyze volatile compounds in air, so samples must
be introduced in the gas phase. HSS technology involves heating samples of soil
or water in a closed sample container to a known temperature. Heat forces the
volatile components to partition between the sample and the headspace above the
sample. After allowing sufficient time for equilibration to occur, a portion of the
headspace (now containing volatile compounds from the sample) is introduced to
the HAPSITE as a gas sample.
Unknowns are tentatively identified using the National Institute of Standards and
Technology (NIST) mass spectral library. Known compounds can be quantified
using a prepared calibration curve.