Chromatography Forum

Can you please tell me what you have connected to each port. Assuming that you are using a 6 port valve, Agilent would normally plumb the valve as follows:

port 1 Sample in
port 2 Sample Out
port 3 Loop
port 4 To column or inlet
port 5 carrier gas in
port 6 Loop.

As mentioned in my earlier posting, you could have a defective valve. The rotors are marked so that you install them the correct way around. In our case, the rotor was not correctly marked.

Gasman

Are you using the same method as for the checkout sample? Same column, etc., and changes whatsoever? Double-checked the signal is the right one being acquired and saved? Have you used your Carboxen column on any other instruments with success? If you're doing the checkout chrom with a DB5 or something like that instead, have you tried injecting air down that? You won't get any retention but you should still see something.

Gasman: Since the valve installation is under warranty, an Agilent engineer will actually be here tomorrow to make sure it's working as it should (and fix/replace it if it isn't). I didn't watch it be installed the first time, though I wish I had, so I can't tell you exactly how it's plumbed until tomorrow.

Johnny: The method is different. I followed Agilent's checkout procedure exactly when running their checkout solution, with a DB-5 column. I've tried numerous parameter configurations using the brand new Carboxen PLOT column, including some that are similar, though not identical, to the checkout parameters. I've also experimented with an older Agilent PLOT column. None of the gas columns or parameter configurations have given even a nitrogen peak. I've also tried direct injections with both of the two split/splitless inlets, but switching inlets doesn't seem to change anything.

I have injected air into the DB-5 with the same results (or lack thereof).

Do you have a very high voice? Is the atmosphere of your lab, in fact, pure helium? Okay I have no clue, be very interested to see what transpires.

Do you have a very high voice? Is the atmosphere of your lab, in fact, pure helium? Okay I have no clue, be very interested to see what transpires.

I actually suggested the exact same thing yesterday! Seems unlikely, though, as none of us have to wear respirators to work

Problem resolved! Turns out that the actuator was seated incorrectly on the valve. All seems to be running smoothly enough now.

Thanks for everyone's help.