Problems with a 450 GC

[Bárbara]

Does anybody out there already had communication problem between a 450 GC and the software?
I have got a 450-GC in tandem with a triple quadrupole mass spectrometer and the software is the version 7.0
I have to inject a sample list with 50 samples and when we put it up the GC injects like 3 or 4 samples and stops. It does not give me any error message. It just stops and the GC status stays on sample prep.
The problem started after I changed the syringe and the auto sampler bent the needle of the new one. After that the syringe was replaced one more time and the problem started...
After stopping the system just starts to work again after turning the 450 GC off and on one time.
So does anybody have any idea about what is going on with the system and how to fix it?

[Ultimate Science 101]

When the GC stops and remains in "sample prep", where is the failure occurring? At the wash/waste vials or the 2mL sample vial? Do you have an 8400 or 8410 autosampler?

You might double check the 8400/8410 calibration. Also, ensure the syringe holder on the autosampler isn't bent, you can physically adjust it with slight pressure if you feel it's bent erroneously in a particular direction. You should have received a calibration tool for the wash/waste vials with your 8400 autosampler. The manual explains how to perform this calibration/alignment. The 450 GC local control will only allow you to calibrate the autosampler position over the sample vial and injector(s). If the failure is occurring at the sample vial, ensure when you calibrate the position of the autosampler over the vial you adjust the height so it is perhaps 2-3mm above the top of the sample vial with lid on.

Are you using a 10uL syringe or something larger? Ensure the plunger appears to be working well.

Good luck, let us know what happens!

[Bárbara]

It stays on the back at the standby position. I have a CP-8400 autosampler with a 10 uL syringe.
I have alredy checked the calibration of the autosampler and it seems to be okay. Anyway I'll do it one more time.

Thanks for the help!

[Ultimate Science 101]

The one additional "glitch" we have noticed, and perhaps this was more related to GC firmware than an inherent problem... If you have a 1079 PTV on the 450 GC and you are using liquid N2 or CO2 to cryogenically cool the injector, when you have finished running a sample (or sequence) and the injector cools back down to the initial starting temperature, the 450 GC will eventually go into "standby" mode when the standby cooling time has been reached. We've noticed (at least on 6.9.2 Workstation) that this will often kick off communication between the 1200L MS and Workstation software. Also, it doesn't seem possible to get the 450 GC out of the "standby" state by reactivating the method in the software. You either need to press the end standby button on the 450 display, or reactivate another method in MS Workstation that doesn't rely on cryogenic cooling of the injector or has a different initial injector temperature. Perhaps version 7.0 of Workstation has resolved these problems.

Not sure if you are using any sort of cryogenic cooling on your injector, but we figured we'd mention this since we've noticed this problem on more than one occasion. Still, we haven't seen this issue associated with the 8400 autosampler simply remaining in the "sample prep" state.

Make sure you also do a power reboot on your 450 GC before you do the 8400 calibration. Perhaps this will help your problem. Let us know if it goes away. Good luck!