Chromatography Forum

Dear all,

my problem can be described as follows:

I have an Agilent GC 7890 where my syringe volume was defined as 5μL using the Nano Liter adapter.

Hence, the total syringe volume was not transferred, i.e. a factory setting of 10 μL applied.
With a a 5μL syringe in place, half of the intended volume was injected. Having defined 5μL using the instrument's keyboard the sequence was analyzed correctly.

My questions therefore:

With my other Agilent system (6890), the syringe volume and the Nano Liter Adapter were successfully read and transmitted. Shouldn't that be the case with the GC 7890 also?

I have tried various settings and approaches, all of them not being successfull as the total syringe volume didn't change.

Could this be due to the instrument or driver configuration?

Many thanks in advance!

MP

Use Configure in Chemstation to tell the system the syringe size. And each time you change the size of the syringe.

Use Configure in Chemstation to tell the system the syringe size. And each time you change the size of the syringe.

I'm using Empower2 as well as the respective Waters Driver to control the GC. I tried the wizard and the syringe size window but it didn't work.

From my manual for a 7683 ALS with a 6890,
With nanoliter enabled and using a 5ul syringe you get:

injector stop volume (ul)
1 0.1
2 0.5
3 1.0
4 1.5
5 2.0

The book says (using my instrument's) the largest injection volume is 1/2 syringe size. To do this the nanoliter setting must be off.

So the way I read your settings ( 5ul syringe, nanoliter on. injection stop 5), would inject 2 ul.

Can you post a screenshot of your 7890 layout in Empower 2? Also, what ALS model are you using?

I know that with my setup (7683B ALS and 7890 using Empower 2), there is no nanoliter adapter option for this ALS model - the syringe size is specified from a floating toolbar on the Empower 'run samples' screen.

Wouldn't know about empower, what I posted was from my autosampler instruction book. I use a 6890 and 7683 controlled using Chromeperfect.
Regardless the natoliter setting is in/on your GC, and the autosampler only has 5 stops however it's controlled. From what I see for the autosamplers, the largest volume that can be injected is 1/2 syringe volume.

Sorry Bigbear, my query was aimed at max_planck - should have made that a bit clearer!