1. An Introduction to Chromatography What is chromatography? The separation of a mixture by distribution of its components between a mobile and stationary phase over time –mobile phase = solvent or gas –stationary phase = column packing material

3. Purpose of Chromatography AnalyticalAnalytical - determine chemical composition of a sample PreparativePreparative - purify and collect one or more components of a sample

4. Two-stage pressure regulator Carrier gas supply Flow controller Rotameter Flow splitter Syringe Injector Detector Temperature controlled zones Column Schematic of a Gas Chromatograph

5. Carrier Gas Supply

6. 300Vdc Injector and Detector

8. 300Vdc

10. Injection types

11. A Capillary Column for GLC Fused silica tubing d c  0.3 mm d f  1  m L = 15 - 60 m Polydimethylsiloxane (silicone) Good for retaining and separating nonpolar solutes by boiling point A thin layer of nonvolatile stationary phase is coating on the inner wall of the tubing (WCOT)

15. Si O OH Si O OH Si O OH Si O OH Si OH + Si Cl CH 3 Si O Cl CH 3 Si O Cl + CH 3 CH3OH Si O OCH 3 CH 3

16. 1 2 3 4 567 8 9 8 7 6 5 5 4 3 2 1 0102030 Isothermal at 45 o C 0102030 Isothermal at 145 o C 0102030 6090120150180 Time Temperature( o C) Programmed from 30 o to 180 o C Effect of temperature on gas chromatograms

17. Capillary GC-MS Fused silica Column Transfer Line Quadruple MS GCData system

18. Sample Carrier Packed column GC-MS Interface To MS Skimmer To vacuum pump Nozzel From GC Jet separator

19. Gaseous ion sources Mass analyzer Ion transducer Signal processor Ion inlet Vacuum pump 10 -5 to 10 -8 torr Components of a Mass Spectrometer

22. Sample inlet batch inlet direct probe inlet chromatographic inlet

23. Vacuum pump Heating coil Ionization chamber Direct insertion probe A sample probe for inserting a sample directly into an ion source Direct probe

24. Molecular leak Repeller Electron beam Heater Shield Filament 1 st accelerating slit Focusing slit 2 nd accelerating slit Anode To mass analyzer

26. Ions with unstable trajectories Ions with stable trajectories Ion source Dc and ac oltages Quadruple Mass Spectrometer

27. Continuous Dynode Electron Multiplier Resistive conductive surface GND 2kV