Chromatography Forum

Hi all,
I am trying to tune up and calibrate our ZQ mass spectrometer. I followed the instructions and injected using the hamilton sysringe and the pump the API solution. Now I wanted to injecte again but the pump does not go back to the starrting possition on its own. Does anyone know how to acomplish this?
Thank you

I don't know that particular built-in syringe pump, but usually there is a simple mechanical way to disengage the block that pushes the syringe plunger from the screw thread that drives it, so you can slide it manually back to the start. There will be a knob to pull or something to push...