Mass amu mass spectrum n c c n h c o c o n n c h c 3

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Mass (amu) Mass Spectrum N C C N H C O C O N N C H C 3 H C 3 H Mass Spectrometer A Typical Mass Spectrum Typical sample: isolated compound (~1 nanogram)
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107 + _ + _ e - e - e - + + + + + + _ Electron Collector (Trap) Repeller Extraction Plate Filament to Analyzer Inlet Electrons Neutral Molecules Positive Ions Electron Impact Ionization Source
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108 Mass Filter Mass Spectrometer Schematic Inlet Ion Source Detector Data System High Vacuum System Rough pumps Rotary pumps Turbo pumps Diffusion pumps Vapor HPLC GC Solids probe MALDI ESI FAB EI/CI TOF Quadrupole Ion Trap Mag. Sector FTMS Microch plate Electron Mult. PC’s UNIX Mac
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109 ion trajectory not in register (too heavy ) Ion Source Detector ion trajectory not in register (too light) ion trajectory in register S N Magnetic Sector Mass Analyzer Electromagnet
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110 Quadrupole Mass Analyzer A quadrupole mass filter consists of four parallel metal rods with different charges The applied voltages affect the trajectory of ions traveling down the flight path For given dc and ac voltages, only ions of a certain mass-to-charge ratio pass through the quadrupole filter and all other ions are thrown out of their original path
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111 Detector Ion Source + _ _ DC and AC Voltages Quadrupole Ion Filter resonant ion non-resonant ion +
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112 Mass Filter Mass Spectrometer Schematic Inlet Ion Source Detector Data System High Vacuum System Rough pumps Rotary pumps Turbo pumps Diffusion pumps Vapor HPLC GC Solids probe MALDI ESI FAB EI/CI TOF Quadrupole Ion Trap Mag. Sector FTMS Microch plate Electron Mult. PC’s UNIX Mac
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113 MS Detectors Early detectors used photographic film Today’s detectors (ion channel and electron multipliers) produce electronic signals via 2 ry electronic emission when struck by an ion Timing mechanisms integrate these signals with scanning voltages to allow the instrument to report which m/z has struck the detector Need constant and regular calibration
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114 Mass Detectors Electron Multiplier
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117 Club Drugs Column: Heliflex ® AT -1ms 30m x 0.25mm x 0.25µm (Part No. 15897 ) Column Temp: 140°C (1min hold) to 300°C (3min hold) at 10°C/min Carrier Gas: Helium at 0.8mL/min (24cm/sec) Detector: FID at 340 °C 1. Methamphetamine (0.18mg/mL) 2. 4-Methoxyamphetamine (0.18mg/mL) 3. 2,3-MDA (0.18mg/mL) 4. 3,4-MDA (0.18mg/mL) 5. 2,3-MDMA (0.18mg/mL) 6. 3,4-MDMA (0.18mg/mL) 7. 4-Bromo-2,5-dimethoxyphenethylamine (0.18mg/mL) 8. Ketamine (0.18mg/mL) 9. Phencyclidine (0.18mg/mL) 10. Cocaine (0.18mg/mL) 11. Flunitazepam (0.18mg/mL)
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