Does nobody has this problem?

Is the injector volume compatible with your syringe?

Maybe the calculator checks your system and can't allow it?

I am guessing the error lies in the communication between chemstation and the combipal. You don't have a standard ALS (like a 7683 or 7693 ALS) on another system that you could troubleshoot with do you?

The injection volume is dependent on what they're using to inject. The standard autosampler does 0.1-10 uL with the standard syringe, they sell syringes with volumes much larger for use with PTV/MMI large volume injections.

The configuration of the combi pal is likely limiting the injection volume, likely because of the syringe size configured.

Have you contacted Agilent? You have a bunch of complicating factors. The calculator assumes all solvent goes into the column at the injection time, but the "injection time" is really whenever you program the PTV to jump the temperature up at which point some (unspecified) amount of solvent has evaporated out of the split of the MMI. You need some way to correct for the timing difference (seems kind of easy - just add the delay to the calculator time) and the unknown fraction of solvent going on column (seems much trickier).

Thanks for your answers!

Yes, I have a CombiPal and the chemstation solvent elimination calculator seems to ignore the installed syringe type (tested with 10uL, 100uL and 250 uL syringes which were recognised by combipal and chemstation).

I only have this system, no chance to test the solvent elimination calculator anywhere else.

It is only the chemstation solvent elimination calculator which does not allow me to use volumens above 0.25uL in its calculation. I can inject however any volume with chemstation and combipal that the syringe allows. It would have been nice to find some initial parameters with the calculator.

I have contacted Agilent several times with no anwer yet on that problem.

Anyone aware of a software patch to overcome the problem or anyone having the same issues as me?

What version of chemstation are you using and are you using addon software to control the combipal or the hand held?

Go to help > about to get your chemstation version. The newest revision of the software is C.01.05 Openlab chemstation. There ARE some updates to the MMI calculators so it is possible your issue is fixed in a later revision, but it may be possible to fix it with what you have, just need more info.

Also what is the firmware rev of the GC? Go to the front panel and hit status and then clear, the newest is A.01.14.

What about the combipal firmware?

We run the GC-MS version of chemstation

G 1701 E.02.02 SP1

How about the GC firmware version?

I'm looking through all of the known issues and I don't see anything that matches your particular problem--there are some fixes for MMI/PTV issues in the last few versions (A.01.15 is actually the newest, and if you have something earlier than .14 or .13 it is possible firmware may address the problem.)

http://www.chem.agilent.com/Library/usermanuals/Public/G3510-90020.pdf

This tutorial shows injection volumes of 1 uL, 5 uL etc.. if firmware does not fix it I would personally recommend reinstalling the software. Just make sure you have your license information handy, and then backup your instrument directory (in c:\msdchem the \1\ folder will contain your methods, data, and sequences.)

Hi Alex,

took a while to get all the info you requested

GC Firmware: A.01.14 (can we update the firmware ourselves?)

PAL Firmware 4.1.3

Chemstation G1791 E.02.02 SP1

Already tried reinstalling the software, but the bug in the calculator remains. I guess the calculator does not get the info from the combipal which syringe is installed.

I also saw the tutorial earlier and that they have 5uL in their window. Maybe they used Agilent autosampler?

Maybe we are the only config in the world with an MMI and a CombiPal and that chemstation version :-(

Hey, firmware looks good and it is interesting that the problem is still there after reinstalling. Not impossible that the problem is still firmware/software, but much less likely.

Go here to get the new firmware update tool, this actually came out 2-3 months ago and is easier to use than Instrument Utilities: http://www.chem.agilent.com/Library/firmware/Public/GC%20Firmware%20Update%20Tool.pdf

Definitely something you can do yourself, you can grab firmware updates here: http://www.chem.agilent.com/Workspaces/firmware/Public/050307/default.aspx (I googled agilent 7890A firmware) -- note that the 7890B is a new model and without a few HW changes it would be incompatible. The A.01.15 bin file is what you want.

I doubt you're the only person in the world with this config, if it makes you feel better :). I've only run into a few MMI inlets so my experience with the calculator is kind of slim. I think you're right about this having something to do with the calculator detecting the wrong syringe size somehow--the purpose of MMI and the solvent elimination calculator is being able to do large volume injections, so being restricted to 0.25 uL kind of defeats the purpose :).

I'll do some looking to see if I can find an answer, but if I were you I would contact Agilent or your area's service rep. Troubleshooting situations with 3rd party ALS and new hardware often requires getting in touch with the right person, but I think Agilent can help you.

Are you able to do larger volume injections not using the calculator? Like a 2 or 3 uL injection of hexane with a high split ratio just to confirm that it is the calculator at fault?

I can inject any volume I like from any syringe installed in the combipal using chemstation. The calculator only gives me suggestions on the parameters. So I guess I have to live without these suggestions ;-) as everything is running fine but the calculator.

I just contacted Agilent again with that issue, let's see what they suggest this time.

Thanks for the useful links!

Answer from Agilent: They found the same error as me, when running the calculator.

I will keep you updated on this issue.

no update yet from Agilent...

In the meantime we just ignore the described error message and get good results from the suggested values by the calculator anyway. So everyone getting the same error just ignore it. So far it worked for me for solvent vent up to 250uL volumne with the solvent hexane. Good peaks, good upscaling and amazing sensitivity. Even 3 weeks of continous sample injection (sediment extracts for PAH analysis) proofed to be robust.

Hi Tobias, I was finally able to get a system with MMI and CTC to use and was able to reproduce your problem.

The situation appears to be that the calculator uses the syringe volume configured in chemstation (or masshunter, or msd chemstation.) With a CTC installed the data system does not know what the syringe size is, so it defaults to 0.25 uL syringe. This should be fixed in future releases--when I find out for sure that it is fixed I'll try and remember to come post an update :).