****************************************************************************** From: "Brian Arbogast" Date: Thu, 10 Feb 2000 09:13:05 -0800 Subject: LCQ custom calibration reference files Organization: Network for Education and Research in Oregon Greetings, We don't know yet how to use alternate to Ultramark calibration standards on the LCQ. On our other instruments it's a simple matter to enter mass lists, calibration reference files, and use them to calibrate. Is it also easy on the LCQ? Could anyone give us pointers? Thanks Much, Brian ****************************************************************************** From: "M Sweeney - MSMS Consulting" Date: Fri, 11 Feb 2000 16:06:52 GMT Subject: Re: LCQ custom calibration reference files Organization: EarthLink Network, Inc. Brian There was a set of posts on this on the ABRF group recently. Try http://www.abrf.org/archives/hmail/9927/index.html#33 and then make sure to check the few other messages above the main thread group. I don't know why these are not included in the thread listed there. The answer is; this is not possible in the same way as it is on other instruments. The LCQ uses the Ultramark to set the trap parameters up and this is not something the avg.. Jane/Joe should try. Two suggestions arose from the discussion; tune using nanospray or have a second set of syringe and fused silica sample transfer line dedicated for Ultramark. The nanospray method was issued with the caveat that it is not good for EM calibrations. The reason most people don't want to use Ultramark is that it can leave a background problem after tuning. By using a dedicated "rig" for Ultramark and purchasing the little cap for the heated capillary from Finnigan, much of the background can be avoided. One can make a two-point calibration correction to the calibration using the diagnostic tab menu choice for calibration. This allows one to correct for any calibration errors observed on the instrument without re-'Ultramarking' the system. Finnigan is looking into this option for future software releases it sounds like. Not being a trap math guru myself, I much prefer to trust Finnigan's great R&D staff to decide how my trap is set-up. The background issues can be worked around fairly easily in most cases. They are a certain frustration, however using the observations you can read on the ABRF, they may be greatly reduced and understood. sorry for my long windedness Matt Sweeney mattsweeney@earthlink.net Mass Spec Consulting Training/Operations/Consulting/Method Development LC/MS Pharmacokinetics, Peptides, Proteins, Metabolism, Maintenance Classes, Specialist in Finnigan Equipment and Software ******************************************************************************