7694 Headspace Versions

[AZBiodiesel]

What is the difference between the agilent 7694 g1298 and g1290?

Thanks,

[GasMan]

I think you mean G1289 and G1290.

The G1289 has the flow and vial pressure supplied by the GC.

The G1290 has a manual controls for flow and vial pressurization built in.

Gasman

[AZBiodiesel]

is there a benefit to having one or the other? What about the auxillary EPC module what advantage does that give you?

Also does anyone have experience with pluming the HS sampler directly into the inlet compared to using the transfer line/needle through the septum?

Thanks,

[GasMan]

It depends what you intend to do.

If you have the HSS dedicated to one GC, and the GC is controlled by a data system, then you can have the set points for the HSS as part of the method when you have the EPC version. If on the otherhand you intend to move the HSS around between several GC's, then the manual pneumatics make it easy to move between the GC's as you do not have to disconnect the EPC plumbing each time.

Gasman

[AZBiodiesel]

The HS will be dedicated to one gc. I will be putting a 7683 onto that inlet every now and then though, could there be a space issue or contamination issue?

[krickos]

If dedicated I would recommend having 2 separate injections ports.

One with traditional split/splitless for your auto injector whenever you hook it on. Will not be a space issue.

The second port dedicated for HS. Use a "volatile inlet" where the headspace T-line is connected. No cold spot issues, low volume, no liner to be exchanged. A bit tricker to connect column.

[AZBiodiesel]

Thanks Krickos,

The setup will be:
6890GC dual FID
S/SL Front inlet with stabiliwax column
Cool On Column Back inlet with DB5-ht column

The front inlet will have the 7694 connected via hard line and auxiliary EPC. The back inlet will have a 7683 on it.

I will be removing the wax column when I do high temp runs on the DB5.