fluorometry - end of slide

• Fluorometry


  When light as absorbed by the matter to the absorber; molecule gets excited then spontaneously returns to the ground state
• Vibrational relaxation


  Excess energy = heat by collisions of solute + solvent
• Photoluminescence 


  longer wavelength is re-emitted after 10-8 seconds or longer
• Quantum efficiency factor or Yield 


  intensity of fluorescent emission that can vary to no fluorescence (zero) to all excited molecules (unity)
• INSTRUMENTATION OF A FLUOROMETER (1-11)

  1. Light source
  2. Focusing lens
  3. Monochromator
  4. Sample cuvet
  5. Emission monochromator
  6. Photomultiplier tube
  7. Signal outage amplifier
  8. Display
  9. Reference beam photosensor
  10. Source supply
  11. Light block
• Nephelometry


  Measures scattered light at a right angle
• Nephelometer


  a photometer designed to measure light scattered by a colloidal or colloidal-like suspension
• Right angle


  Perpendicular - 90°
• Ideal nephelometer instrument


  Free of stray light
• Turbidimetry 


  measures the reduction in the light transmission caused by particle formation; quantifies the residual light transmitted
• Reflectance spectromety


  a beam of light is directed to a flat surface
• White surface


  serves as maximum reflection and zero concentration standard
• Black surface


  serves as zero reflection and high concentration standard
• ESSENTIAL COMPONENTS OF REFLECTANCE SPECTROMETRY

  1. Light source
  2. Slit
  3. Filter
  4. Collimating lens
  5. Test surface
  6. Collimating lens
  7. Detector
  8. Readout device
• Powerful quali and quanti analytical technique that is used to measure a wide range of clinically relevant analytes

  Mass Spectrometry
• An analytical instrument that ionized target molecules

  Mass spectrometer
• A process by which a mixture of ionic species is identifies according to the mass to charge (m/z) ratio ( ions)

  Mass analysis
• Unfragmented ion of the original molecule

  Molecular ion
• Ions with the highest abundance of 100%

  Base peak
• Represented by vertical dashed lines

  Fragmentation patters
• Uses radio frequency and direct current

  Quadrupole Mass Filter (QMF)
• Measures time it takes ions of different masses to move from the ion source to

  Time of Flight Mass Analyzer
• Ionization sources


  electro spray ionization (ESI)

  sonics spray ionization (SSI)

  atmospheric pressure chemical ionization (APCI)