Chromatography Forum

hello again, this is a follow up to my previous post. Unfortunately nobody replied I tried to play a little bit with this Varian 3800 Saturn 2000 system that we have here. I set up a selected ion storage method only to find out that the sensitivity of the instrument is really, really but really bad.... I am getting a limit of detection 3:1 at 2000ng/ml where with quadropole instruments I was able to get down to 20-40 times lower. are there any tricks in ion trap MS that one could use to lower the detection limit?
In general what are the normal detection limits for such an instrument
what about the temperature of the ion trap. at the moment is set at 200 but i do get quite strange looking spectra even if I am monitoring just 20 ions.
I will continue experimenting but i was hoping for some help.
Thanks in advance

Giorgi,
I had the same sort of problem too.
We have the basic version of the Saturn 2000.
Contact Varian - I think there is a chip upgrade package for SIS?
Maybe you have it installed.
I will try to do SIS on ours again and see what happens.

If you are new to Trap you need to clean it if ion time is <15000.
Have you got silchrom electrodes (blue colour electrodes)?
Have a look at Schimels post in gas chromatography "Ion Trap Cleaning".
I have been investigating the use of wool in the injector - I find it is best to run with empty liner if you can.
WK