Problems with DANI GC master TOF

[georgij23]

Dear all, I would like to ask you some questions.
We have bought in lab DANI GC master TOF. In the first day he dosnt check autotune intensity normal she is > 1000000 we has 950000. Seller say it is ok. We start calibration, after calibration (PCBs) his intensity decrease in 500000. Seller recommended increase multiplier value, intensity has raised 800000 but any time she is < 1000000. We inject 2-3 samples and after intensity decrease in 500000. Seller say to be necessary cleaning detector, take away tof and after 1 week he will back in lab. We have autotune test and has same problems. First start intensity is about 950000 after calibration about 500000. I inject sample we dosnt see peaks with intensity 500000. I call seller he say need cleaning detector. I not to trust seller because after 30-50 injection it the standards device need cleaning detector. I write DANI instruments but they send my email to seller. I tell with seller about technical service from DANI but they price is very high ( 7500 euro). We has assumption that device is used, maybe we mistake, but problem is. I change liner, septum, column. Maybe any one knows something about this device??? Please help

[Amirav]

I am not directly familiar with the Dani Master TOF but its concept of working is like that of the Markes TOF via pulsing the ion source voltages. Consequently, it does not have any reading and/or long term stabilization of the emission current and signal. Accordingly, the filament work function is being changed by the solvent hence the emission current and signal is reduced long after the elution of the solvent.
If I am correct you need to increase the solvent delay and the magnitude of the effect that you report will be reduced plus after long time filament operation the effect that you report might be reduced but it will always stay at some magnitude. You may also change the solvent of your sample and that may also affect the magnitude of your effect.
If you wish to communicate with me off line please write to amirav@tau.ac.il