Chromatography Forum

Dear Experts,

I have a Agilent 7890 GC/MS into which I am manually injecting a variety of ppm to ppb samples. I was considering creating SIM profiles of the low ppm compounds but also wanted to scan simultaneously. Are there any conflicts in doing both at the same time? What is the effective range of a SIM profile such that they do not overlap with one another? .. suggestions

I'm assuming you have a 5975 or an upgraded 5973 attached to the 7890.

You can choose for each compound to use a SIM signal or a full scan signal when you set up the calibration. I forget where you set the SIM windows and ions but it was pretty simple to do. Both the full scan and SIM data will be available (it's not one or the other). I haven't had any conflicts. If you're asking how wide you have to make each SIM 'window' that depends mostly on chromatographic behavior and the limitation on how many SIM ions are being scanned for at any one time (I think I capped it at 8 ions at once... I think...).