Analytical methods

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Analytical methods
Houdková Chocholácová
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Analytical methods

• Absolute analytical methods
• (direct evaluation of the analytical signals
  with regard to the analyte concentration)
• Relative analytical methods (which use
  calibration function, sample standards are
  obligatory)

• Gravimetry
• Volumetry (titration methods)
• Instrumental methods CZE
• GC

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Electromigration methods

• use motion of ionized particle in the electrical
  field
• velocity motion is directly proportional to their
  charge and size

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Main variants of the electromigration methods
Capillary Zone Electrophoresis (CZE) Capillary Gel Electrophoresis (CGE) Micellar Electrokinetic Capillary Chromatography (MECC) Capillary Electrochromatography (CE) Capillary Isoelectric Focusing (CIEF) Capillary Isotachophoresis (CITP)
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CZEseparation and determination of cations,
anions and components without charge

• INSTRUMENTATION
• Capillary
• Source 20 30 kV
• Platinum electrodes
• Vials with buffer solutions
• Detectors
• Time (such 10 minutes)
• Electroforetogram

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Capillary

• size 60 cm x 75 µm
• silica capillary covered by polyamide
• the whole capillary contains 10 µl, sampling
  volume is 10 nl
• various variant of sampling (hydrodynamic,
  electrokinetic)

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Principle of CZE

• method for separation and determination of
  cations, anions and so components without
  charge on the basis of diferent electrophoretic
  movement
• sample at start ? insert electrical field ?
  components A,B are moving with diferent constant
  speed towards to electrode ? origin zone
• to origin electroosmotic flow (EOF) and his
  impact on separation and shape peaks

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Application

• determination of dye at foodstuff
• monitoring composition of foodstuff during the
  production and storage
• pollution
• analyse of DNA (genetic engineering)
• and so, and so, and so

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Reference

• website
• Analytická chemie, Lumír Sommer (textbook)
• laboratory from ISA