Analyte detection

Analyte detection - context
Detection techniques - purpose
Chromatography - detector system
Detectors ... ?
Coupling chromatography & detectors
     Flame ionization detector (FID)
           General description of FID
           Illustration of FID
           Detailled description of FID
     Electron Capture Detector (ECD)
           General description of ECD
           Illustration of ECD
           Detailled description of ECD
     Comparison FID and ECD
           Type of detector
     UV-visible absorption detector
           General description of UV-vis-AD
                 UV frequency range
                 Principles of light absorption
                       Jablonski scheme
                 Chromophores
           Illustration of the UV-vis-AD
           Detailed description of UV-vis-AD
     Fluorescence detector (FD)
           General description of FD
                 Fluorescent light
           Illustration of FD
           Detailled description of FD
     Mass spectrometric detection (MSD)
           Brief description of MSD
End of lesson


Terminology

Concentration vs. mass flow dependent detectors

 

   Detectors can also be grouped into:

1. Concentration dependent detector

  • signal is related to the concentration of solute in the detector
  • dilution with make-up gas in GC lowers the response

  • examples: ECD, UV-visible absorbance detection, fluorescence detection

2. Mass flow dependent detectors

  • usually destroys the analyte
  • signal is related to the rate at which solute molecules enter the detector (i.e., the flow rate of the carrier gas)
  • the response is unaffected by make-up gas in the detector

  • examples: FID, MSD