Chromatography Forum

we bought a Thermo TSQ Quantum in october 2008. The first time we were very glad with the system until we changed the board into a new one (3000 transitions) Nearly the same time we installed a backflush system. Then we had many problems with sensitivity and small areas. We increased the injection volume from 1 µl to 2 µl but we did not reached the same level than before. Then Thermo changed the source into XLS.But there was no improvement.
e.g. area of Triphenylphosphat at 1 µl injection volume, old board and without backflush round about 900000 and now with the new board, XLS source, backflush and 2 µl 300000.
Then we realized that the wire of the filament bends so that there's no signal left anytime.

Did anyone make the same experiences?

You are not alone.

Search my previous post and you will see my frustration with this system. We called in the service engineer at least once a month in about two years after the installation. After updated to XLS and backflush, the instrument seems to stabilize itself, but the performance is no better than an Agilent GC-single Q-MS.

Check your S/N, even the peak is buried under noise, the software still gives you a double digit S/N. So the theoretical LOD is great, but it simply doesn't deliver in the real world.

Is your Quantum GC still in use or is it out of order?
What does Thermo say to your problem?Our guideline (SANCO) says that within a sequence the difference between beginning and end is not allowed to be more than 20%.Because of the guideline we think about changing our instrument.