Chromatography Forum

Dear fellow chromatographers,

our MS System (Agilent 5973) shows steady peaks of the calibrant PFTBA during all acquisitions. If the valve is switched off under manual tuning the ion peaks do not disappear and change in abundance. Also if the valve is getting purged there is no click sound. Did anybody experienced something like this? Could it be that the valve is steadily open and can't manage to close?

I would be very grateful for any advice!

hi mvlo

sounds like the valve / solenoid is permanently open.
either the valve is defective or the control voltage to the solenoid is continuously on.
you could try to unplug the solenoid connector which is behind the MS lower panel. this will tell you if the valve closes when no voltage is present.

I agree. If it goes away when unplugged then there is a problem with the control board, if it stays then the valve is stuck open and probably needs to be replaced.

I have had them fail before, both open and closed.