Theory of chromatography

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Theory of chromatography
Capacity factor and distribution coefficient
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Theory of chromatography
Retention time
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Theory of chromatography
Retention time
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Theory of chromatography
Resolution and selectivity
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Theory of chromatography
Plate concept
van Deemter Equation
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Resolution
Shape and yield of peak
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Binary chromatography

• Isocratic chromatography
• One mobile phase
• Poor resolution and selectivity
• Binary chromatography
• Two mobile phases
• Much higher resolution and selectivity
• Approach
• Use an initial mobile phase which promotes strong
  interactions between the stationary phase and
  molecules that need to be retained
• Wait till unbound or weakly interacting molecules
  have been removed from the column
• Switch over to a second mobile phase in a
  appropriate manner to sequentially release or
  elute out the bound components

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Binary chromatography equipment
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Binary chromatography chromatogram
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Binary chromatography thumb rules
Ion-exchange First mobile phase low ionic
strength Second mobile phase high ionic
strength Affinity First mobile phase
physiological conditions, sometimes high ionic
strength Second mobile phase acidic pH,
sometimes low ionic strength Reverse
phase First mobile phase polar Second mobile
phase non-polar Hydrophobic interaction First
mobile phase High concentration of
anti-chaotropic salt Second mobile phase
Anti-chaotropic salt free solution
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Mobile phase changeover
100
Linear
second mobile phase
Step
Non-linear
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