Chapter:
Topic:
PURGEAND TRAP CONCENTRATOR
HARDWAREORIENTATION
Cooling fan for traps
maintains selected
adsorbtion temperature
and rapidly lowers trap
temperature from
desorbtion temperature
( typically 200 C )
Purge and Trap Sample
ConcentratorOption ismounted in
the special ducted heated valve
oven located on the left side of the
8610C Gas Chromatograph. The
Purge and Trap option is not
available on the Model 310 GC.
Purge vessel uses
disposable 16mm test
tubes and rugged needle
sparging tube. Sparge
head allows gas standards
to be spiked in through
built-in septum port .
The SRI Purge and Trap concentrator allows low levels of organic compounds in water to be
automatically extracted from the watermatrix and collected on one or two seriesmounted
adsorbent traps. The purge and trap technique is applicable to a broad range of molecules from
about C3 to C12. Molecules heavier than C12 do not purgewell from water nor do polar
moleculeswhich resist purging due to their solubility. The SRI Purge and Trap is unique
because of the dual trap design which allows two different adsorbent trapping materials to be
used, and each material can be adsorbed and desorbed at individual temperatures and different
times. This flexibility allows for tighter desorbtion bandwidths, and greater water rejection
than other Purge and trap designswhich have only a single mixed adsorbent bed trap.
Additionally, the disposable test tubes which hold thewater sample are inexpensive (5 cents
each U.S) so they can be thrown away in the event of contamination. A 10 position
autosampler can be easily added to the Purge and trap for un-attended operation.
