ASTM 3612/TOGA/DissolvedGasGC
RevisedOctober 2013
TheGC is configuredwith two detec-
tors ( TCD andFID/Methanizer )
which are connected in series at the
end of the two separation columns
( Haysep-D andHaysep-N).
A 10port gas sampling valve ( GSV )
injects 1ml of headspace gas into the
columnswhere the various gasmole-
clules are separated. The valve is
connected as shown. This diagram is
also displayed on the cover of the
GC’s valve oven.
The valve is plumbed to backflush the
columnswhen the peaks of interest
( H2, CO, CO2, ethane, ethylene and
acetylenehaveeluted.
Beforemeasuring liquids, it is helpful
to inject the calibration gas itself with
no liquid in the vial. This permits the
operator to optimize the separationof
the gases of interest, identify and cali-
brate thepeaks etc.
Take a new empty 40ml vial with
septum cap ( CRS part# 279545
) and slide it into
the headspace sampler from the bot-
tom.
