Perform five vacuum evacuation/nitrogen purge cycles.
3.
With the pressure regulator set to 15 psi, turn the valve handle to the “Nitrogen” position for a
3.1.
period of 15 seconds.
Turn on the vacuum pump. Turn the valve handle to the “Vacuum” position.
3.2.
Evacuate the sample vessels down to -25 in Hg as indicated on the valve panel vacuum
3.3.
gauge.
Once the vacuum has stabilized, turn the valve handle to the “Nitrogen” position.
3.4.
Repeat steps 3.1 through 3.4 four more times.
3.5.
Seal the samples under a 15 psi nitrogen atmosphere by turning the valve handle to “Nitrogen”
3.6.
and then to “Run.”
Press the PLAY key to run your selected hydrolysis program.
4.
At the conclusion of the hydrolysis and cooling cycle, remove the temperature probe from the vessel
5.
assembly.
Remove the attenuator, then remove the vessel from the Discover cavity. (The vessel assembly will
6.
still be connected to the valve panel.)
Turn the valve handle to “Vent” to release the remaining nitrogen pressure. Disconnect the pressure
7.
sensing line from the vessel assembly.
Using the wrench set, remove the vessel cap.
8.
Using micro-forceps, remove the microvials from the tray. Use a vacuum centrifuge to remove any
9.
remaining liquid that has condensed in the vials. After drying, samples are ready to dissolve and
cap for transfer to an HPLC system autosampler.
Figure 6. Valve Handle Positions.
