Fundamentals of GC/MS

Gas Chromatograph-Mass Spectrometry

Introduction: What is Mass ?
Mass of Materials
Mass Number and Isotope
Isotopic Abundance of Carbon Atoms
Isotope Abundance Table
Molecular Weight
Introduction: Types of Ions
Example of Mass Spectrum
Base Peak
Molecular Ion Peak
Fragment Ion
Isotope Peak
Ionization Modes: EI
Three Ionization Modes
Features of EI
Molecular Ion Produced by EI
Fragment Ion Produced by EI
Full View of EI Process
Producing EI Mass Spectrum
Electron Energy and Mass Spectrum
Ionization Modes: PCI
Three Ionization Modes
Features of PCI
Spectrum of PCI
Appropriate Conditions of PCI
Ionization Process of PCI
Reactions Ionizing Sample Molecules
Proton Affinity
Comparison of Reagent Gasses
Ionization Modes:NCI
Three Ionization Modes
Features of NCI
Spectrum of NCI
Ionization Process of NCI
Molecular Peak and Fragmentation
Negative ion Production Processes
Useful Application Fields
Hardware: Ion Source
Overview of Ion Source
Structure of Ion Source
To Control Ionization
The Role of Magnets
Comparison of Sources
Hardware: Mass Analyzer
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
Hardware: Scan Mode and SIM Mode
Scan Mode and SIM Mode
Scan Mode
Total Ion Chromatogram (TIC)
Mass Chromatogram (MC)
SIM Mode
FASST (Fast Automated Scan/SIM Mode)
Hardware: Detector
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
Hardware: Vacuum System
Overview of Vacuum System
Why Does MS Require High Vacuum?
Turbomolecular Pump
Single Pumping System
Limitation Factors of Vacuum
Differential Pumping System
Dual Inlet Turbomolecular Pump
TMP Pumping System and Column
Parameters Expressing Performance of Mass Analyzer :Mass Resolution and Peak Width
Over view of Mass Peak
Mass Resolution and Peak Width
Overlapping Profile of Two Peaks
How Dose a Mass Peak Define Width
Peak Width and Mass Scan Line
Parameters Expressing Performance of Mass Analyzer :Signal-to-Noise Ratio
Definition of S/N Ratio
The Factors Determining S/N Ratio
Simulation of S/N Ratio
Qualitative Methods of GC/MS Analysis: Retention Time and Retention Index
Chromatographic Separation
Distribution Coefficient
Retention Time Parameters
Factors Affecting Retention Time
Qualitative Analysis by GC
Relative Retention
Retention Index(Isothermal)
Linear Retention Index(LRI)
Identification Using LRI
Qualitative Methods of GC/MS Analysis: Library Search
An Easy Tool for Identification
Searching Libraries
Search Methods of Libraries
Combined Use of Retention Index
Examples of Spectral Library

Fundamental Guide

Fundamental Guide to GCMS