Re: MassSpec: LCQ

Len Packman (lcp2@mole.bio.cam.ac.uk)
Fri, 10 Dec 1999 16:24:32 +0000

Thanks to all for terrific discussion on LCQ. A change from 1%
formic/70%MeOH to 0.1% formic/70%MeOH seems to have done the trick for
giving many more 2+ states. I now get higher mass ions (>2000Da) appearing
as 2+ states which were previously unseen.

To answer some queries:
1. Solution is fresh every 2-3 days to minimise esterification
2. 1+ states are not fragments
3. Use of capillary temp 150C instead of 200C on LCQ Classic improves yield
of 2+
4. Reduction of capillary temp below about 120C gives additional ion
clusters (presumably solvent adducts) in nanospray

Len

*********************************************************************
Dr Len C. Packman
Assistant Director of Research
Protein and Nucleic Acid Chemistry Facility
Department of Biochemistry
University of Cambridge
80 Tennis Court Road
Old Addenbrookes Site
Cambridge, CB2 1GA, UK
Tel: +44 (1223) 333639
FAX: +44 (1223) 766002
e-mail: lcp2@mole.bio.cam.ac.uk
Visit my WWW page at http://www.bio.cam.ac.uk/proj/adr/PNAC/pnac.html