Gas Chromatography - Mass Spectrometry

 Chromatographic Considerations

• Basic Principles of the Chromatographic Process - Partition Theory
• Mechanisms of Gas Chromatography
• the equilibrium / distribution constant & solute-stationary phase interactions
• Temperature / Retention Relationship
• Sample Introduction principles and description of split / splitless, large volume (PTV) and on-column injection systems.
• Particular attention will be paid to carrier flow and sample loading
  

 GC- MS Hardware

• Low bleed phases and column geometries' compatible with mass selective detection
• The Mass Selective Detector
• System Hardware - description and operational principles (system overview, transfer line, pumping systems, ion source, quadrupole mass analyser, ion trap (where appropriate), electron multipliers and detector electronics)
• Why is Vacuum Required? - including monitoring and maintaining vacuum systems
• The Ion Source - why is ionisation necessary?
• Operating principle of the ion source, consideration of ion formation / fragmentation, beam collimation and acceleration.
• Solvent vent time and ion source maintenance
• Quadrupole Mass Filters - construction and operating principles
• Electron Multiplier principle of operation as both detector and amplifier.
  

 Tuning, Data Acquisition and Sample Interpretation

• Flow Chart of a Typical Auto-Tune Routine, tuning standards, relative abundance, isotope ratios, mass assignments and peak width.
• Detector Electronics Mathieu diagrams used to explain the significance of AMU gain and offset, X-ray voltage, electron multiplier voltage
• Troubleshooting from the Auto Tune Report how to identify system problems such as a dirty ion source
• Air and Water Checks
• Full Scan and Selected Ion Detection Modes principles of each mode, sensitivity enhancement, and scan rate settings
• Common Mass Spectral Features some common fragmentation and isotopic patterns