Chromatography Forum

Anyone deal with precursors to 69, 219, 502 on Autotune? 5973A.
I don't have this with my autotunes on other instruments.
Is this telling me something? I switched from Positive to Negative polarity as I lost my 502 on Autotune. < 1% after using Positive DC current for a year or so... I have better abundance all the way around after switching polarity. I have aprox. 10% -502 on tuning but with precursors now on 69, 219, and 502. All within range though according to tune evalutation.
Thank you. [/img]

Your instrument probably tuned better negative at the factory and at some point someone switched it to positive.

If you life up the case over the MSD there should be a sticker noting which mode it should be used in. If you can't find this sticker you can vent out the system and inspect the quadrapole it should marked there.