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Simulation of Radio Frequency Quadrupole Mass Analyzer. Stephen Jones EPS 109 Final Project 11/27/12. Radio Frequency Mass Analyzer. Used in Mass Spectrometry to separate ions with specific mass/charge (m/z) ratio Design:
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Simulation of Radio Frequency Quadrupole Mass Analyzer Stephen Jones EPS 109 Final Project 11/27/12
Radio Frequency Mass Analyzer Used in Mass Spectrometry to separate ions with specific mass/charge (m/z) ratio Design: Four electrodes with positive and negative DC voltage on diagonally opposite rods RF AC voltage applied 180° out of phase between pairs of diagonal rods Acceleration= (charge)x(E field) /(mass) • Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis 6th Ed.; Brooks/Cole; Belmont, CA 2007.
Radio Frequency Mass Analyzer - continued Both DC and AC potentials are increased during run to obtain m/z spectrum Full scan on the order of milliseconds • Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis 6th Ed.; Brooks/Cole; Belmont, CA 2007.
Stable Stable vs. Unstable Trajectories Stability is determined by Dimensions of RFMA (r0) Mass (m) Charge (e) DC Voltage (U) AC Voltage (V) AC Frequency (ωrf) Stability can be determined with parameters a and q Unstable • F. Muntean, Int. J. Mass. Spec. Ion Proc., 151 (1995) 197-206
Similar to: Simulation Parameters • Field radius = 3.5 cm • Mass 1: 722.66 Dalton • Mass 2: 57.81 Dalton • U = ± 20 Volts • V= ± 400 Volts Molecule 1 (blue) is inside region of stability (a = 0.04, q = 0.4) Molecule 2 (red) is outside region of stability (a = 0.5, q = 0.25) 1,2,3-Tritetradecanoylglycerol http://www.chemfinder.com/chembiofinder/Forms/Search/ContentArea/ChemBioVizSearch.aspx?FormGroupId=8&AppName=CHEMBIOFINDER&AllowFullSearch=true&KeepRecordCountSynchronized=false&CurrentIndex=1 Isopropylamine http://www.chemfinder.com/chembiofinder/Forms/Search/ContentArea/ChemBioVizSearch.aspx?FormGroupId=8&AppName=CHEMBIOFINDER&AllowFullSearch=true&KeepRecordCountSynchronized=false&CurrentIndex=5
How to Run Run with script: SMJ_EPS109_finalproj.m Function: quad.m