Chromatography Forum

I have a peak at m/z 40 and 45 when I make air spectrum and leak check fial in auto tune. How I can fixed this problem?

You can take a can of the compressed electronics duster which should give a mass in the 50-60m/z range and spray it around the seal to the vacuum chamber while scanning the instrument and watch for that ion to appear and you will pinpoint where the leak is. If you don't see a leak at the seal, then try where the column connects and where the vacuum lines connect. If you find the location of the leak then you can inspect to see if there is anything there that should not be. I have seen a large leak occur by simply finding a hair laying across the o-ring seal before.