Hi Everyone,
I'm working on a Thermo trace 1310 with isq single quadrupole and FID. The autosampler is Triplus RSH with direct and headspace injection capabilities.
We mostly use the MS with different applications (different columns, solvents, injection techniques).
Unfortunately lately none of these methods are working and we're constantly experiencing problems and they are not always the same.
First we had sudden drifts when injecting from the same vial (area counts doubled), than there was a constant downwards drift in area counts. We went through all the usual stuff (liner, septa, syringe change, column reinstalled), tried completely different methods, but we still couldn't achieve repeatability.
We cleaned the inlet which made a slight improvement for one run.
We had an engineer out, who's OQ passed, but once he left we realised all his methods only uses splitless injections, while we only use split.
We tried to run the same component on both split and splitless and while splitless was perfect, split just had a constant downward drift in area counts. The cal line in split was quadratic, in splitless linear.
Engineer came again and replaced the split valve.
Now we don't have the drift, but in random injection the area doubles.
We also run tests on the FID to eliminate MS problems as the engineer just wants to change the multiplier.
FID is giving the same erratic behaviour.
Thank you for reading and looking forward to hearing any suggestions as I'm desperate for a working instrument.
Greta