Separation Science 2

• What is another name for partition chromatography?

  Reversed phase chromatography
• What does the stationary phase in reversed phase chromatography consist of?

  Silica particles with bonded alkyl groups
• How does the stationary phase in reversed phase chromatography differ from normal phase chromatography?

  It is non-polar, unlike normal phase
• Which type of drugs does the stationary phase attract more in reversed phase chromatography?

  Lipophilic (non-polar or less polar) drugs
• What happens during the elution of the column in reversed phase chromatography?

  Competition occurs between solute and solvent
• How does lipophilicity affect the elution time of a molecule?

  More lipophilic molecules elute more slowly
• What is the effect of a more lipophilic solvent on the elution time of a drug?

  It results in a shorter elution time
• What charge does a cation exchange resin have?

  Negatively charged
• How can cations be eluted from a cation exchange resin?

  By increasing Na+ concentration in the buffer
• What happens when the pH is decreased in cation exchange chromatography?

  It neutralizes the negative charge on the surface
• What charge does an anion exchange resin have?

  Positively charged
• What is the principle behind anion exchange chromatography?

  Anions are attracted to positively charged resin
• What is the significance of pH in anion exchange chromatography?

  It affects the binding strength of the analyte
• What is the definition of an eluent?

  Fluid entering the chromatography column
• What is the definition of an eluate?

  Fluid emerging from the bottom of the column
• What does elution refer to in chromatography?

  The process of passing liquid or gas through a column
• What is an analyte?

  The component of interest in chromatography
• What is a solute?

  A component in a solution
• What are the main components of a basic Liquid Chromatography system?

  1. Mobile Phase
  2. Pump
  3. Injector
  4. Column
  5. Detector
• What is isocratic elution?

  Composition of the mobile phase does not change
• What is gradient elution?

  Composition of the mobile phase changes over time
• What is the effect of using gradient elution?

  It speeds up run times and improves separation
• What is the van Deemter Equation used for?

  To analyze factors affecting chromatography resolution
• What is the significance of peak area in quantitative analysis?

  It is directly proportional to the amount of substance
• What are the main steps involved in quantitative analysis?

  1. Sample collection
  2. Analytical experiment
  3. Data acquisition
  4. Data processing
  5. Quantification
• What is a calibration plot used for in quantitative analysis?

  To calculate the concentration from peak area
• How is the concentration of nicotinic acid calculated from peak area?

  Using the slope and intercept from calibration
• What are the types of chromatography and their principles?

  1. Adsorption: Based on polarity differences
  2. Partition: Based on hydrophobicity differences
  3. Ion exchange: Based on charge differences
  4. Gas chromatography: Based on volatility
  5. Permeation: Based on size
  6. Affinity: Based on ligand binding
• What is a common challenge in chromatography regarding analyte concentration?

  Analyte concentration outside the linear range
• What is a solution to the challenge of overlapping analyte peaks?

  Adjusting the mobile phase composition
• What is the effect of sample components eluting at the same time as the analyte?

  It complicates the analysis and identification
• What is the role of the detector in a chromatography system?

  To identify and quantify the analytes
• What is the purpose of a degasser in a chromatography system?

  To remove dissolved gases from the mobile phase
• What is the significance of particle size in chromatography?

  It affects the resolution of separation
• What is the effect of stationary phase thickness on chromatography?

  It influences mass transfer and resolution
• What is the relationship between lipophilicity and retention time in reversed phase chromatography?

  More lipophilic compounds have longer retention times
• What is the role of the mobile phase in chromatography?

  To transport analytes through the column
• What is the effect of solvent miscibility in chromatography?

  It allows for proper mobile phase composition
• What is the significance of the calibration curve in quantitative analysis?

  It helps determine the concentration of unknowns
• What is the importance of sample preparation in chromatography?

  It ensures accurate and reliable results