Sample molecules are ionized in the ion source after chromatographic separation by a GC. The structure and function of the ion source will be explained here.
- Overview of Ion Source
- Structure of Ion Source
- To Control Ionization
- The Role of Magnets
- Comparison of Sources
A quadrupole(QP) mass analyzer is most extensively used for GC/MS analysis. The mechanical structure of a QP mass analyzer and its principles will be explained.
- Overview of Mass Analyzer
- Structure of QP Mass Analyzer
- Applied Voltages to Rods
- Mass Filtering by QP Analyzer
- Motion Equation of QP Analyzer
- Stability Region and Ion Trajectory
- Stability Region and Scan Line
Scan Mode and SIM Mode are the generally used analysis mode. Operation principles of the two modes will be explained, and a new analysis mode will be introduced.
- Scan Mode and SIM Mode
- Scan Mode
- Total Ion Chromatogram(TIC)
- Mass Chromatogram(MC)
- SIM Mode
- FASST (Fast Automated Scan/SIM Mode)
An electron multiplier is generally used as a detector on a mass spectrometer. The structure of an electron multiplier system will be described here.
- Overview of Detector System
- Structure of Electron Multiplier (Discrete-Dynode Type)
- Electron Multiplication
- Gain of Electron Multiplier
- Structure of Electron Multiplier (Continuous-Dynode Type)
- Conversion Dynode
The mass spectrometer is housed in a vacuum. The basic knowledge of vacuum system, which is needed to understand GC/MS analysis, will be provided here.
- Overview of Vacuum System
- Why Does MS Require High Vacuum?
- Turbomolecular Pump
- Single Pumping System
- Limitation Factors of Vacuum
- Differential Pumping System
- Single Pumping System and Differential Pumping System
- Dual Inlet Turbomolecular Pump
- TMP Pumping System and Column