by
bor9455 » Sun Nov 09, 2014 9:45 pm
I've got a 6890N w/ ALS with one injector tower (all good), and a new-to-us 7694e headspace sampler.
How does the 7694e work with chemstation and the 6890N? It doesn't pop up as an option. I've connected it via the serial-type cable. Do I run it in manual mode somehow? Does that mean I can only do one vial at a time, or have to push start for each injection or something? Headspace is connected via needle-through-septum. Also, any advice on how to set the vial pressure and carrier pressure knobs on the headspace is appreciated.
Method should be quite simple - just heating the vial for 30 min or so, maybe we'll get into a proper method with diluents etc if we need more reproducibility, not sure.
I know it's a bit of an odd setup. Small company, so we kind of cobble these things together on an as-needed basis and I try to figure it out.
Thanks for any help,
- Russ
I cannot speak to the ChemStation side of the headspace, but I can speak to the headspace portion set up. My lab uses Empower to run our instruments, which is similar to ChemStation (or so I'm told) but not exactly compatible. When we run headspace analysis, the only parameters that I control with the software is for the GC. I start the sample set, complete with all my standard parameters (inlet temp, detector temp, flows, oven profile, etc) and the vial order as if I were performing direct inject. I then proceed over to the headspace and set up the oven temp, loop temperature, line temperature, pressurization time, loop eq time, etc. Once I have everything set up as needed, I begin a sequence of injections. I am not familiar with the 7694E, it looks similar to the very old model that we used to use with the 5890s. If you scroll through the vial menu, you should see "First Vial" and "Last Vial" as options. This is how you program a sample set of injections. If you have 15 vials, you can set it as First Vial 1 and Last Vial as 15 and after hitting start, walk away and it will work with the GC to inject each vial automatically, while your ChemStation or in my case Empower is along for the ride to catch the data.