I am attempting some hydrocarbon runs on a Saturn 2100T Ion Trap MS. The sample is from a catalysis process called Fischer-Tropsch, which mainly produces 4 major components per carbon number that elute in this order; 1-olefin, n- paraffin, trans-2-olefin, cis-2-olefin.
I'd like to specifically look at the parent ion because of some C13 work, but I am not able to see it. The picture is a scan of C11 (n-paraffin), and even if I zoom in, the parent ion is not there.

[url]Image[/url]
The three large peaks are 57, 71, 85 m/z. I can provide a bigger picture if necessary.

I have tuned the MS, baked the column (though it is a bit older), cleaned the inlet (with new septa) and played with the scanning of the trap - (used EI Auto, shortened the scan time and pre-scan time, dropped the emission current to 5). Nothing has helped. I still get the fragmentation pattern seen in the picture. Further, it does not seem to matter which n-paraffin I look at, they are essentially the same.

It seems as if I am getting some unnecessary fragmentation due to a dirty source or the column just bleeding too much. I understand that CI would be a good option as well, but before I go off and switch all this around I wanted to see the opinion of others. I mainly have worked with Agilent GCMS with quads, not traps.

Thanks.
Will