2.2.3 Chromatography: Principles and Applications

• What is the purpose of chromatography?

  Separate mixture components
• How can the resolution of column chromatography be improved?

  • Using a longer column to increase separation time
  • Optimizing the mobile phase composition and flow rate
  • Selecting a stationary phase with higher surface area
  • Reducing the particle size of the stationary phase
• What is the purpose of the mobile phase in column chromatography?

  To carry the sample through the stationary phase
• What are the advantages and limitations of column chromatography compared to other separation techniques?

  Advantages:

  • High resolving power
  • Ability to separate complex mixtures
  • Preparative-scale separation possible

  
  

  Limitations:

  • Time-consuming
  • Requires large sample volumes
  • Potential for sample loss or degradation
• How does the fractions collection step in column chromatography differ from the eluted molecules step?

  Fractions collection separates the components, while eluted molecules collects the separated components
• The mobile phase in thin-layer chromatography moves by gravity.

  False
• What distinguishes the main types of chromatography?

  Their setup and stationary phase
• Steps in paper chromatography

  1️⃣ Liquid moves by capillary action

  2️⃣ Components separate based on affinity

  3️⃣ Results are analyzed
• What are the three phases shown in the image?

  Mobile phase, Stationary phase, Sample
• What is the stationary phase in thin-layer chromatography?

  Flat plate with thin coating
• What is the purpose of the mobile phase in chromatography?

  • The mobile phase carries the sample through the stationary phase
  • It interacts with the sample components, causing them to separate
  • The different sample components move through the stationary phase at different rates based on their interactions with the mobile and stationary phases
• How does the mobile phase interact with the sample components in column chromatography?

  • The mobile phase carries the sample through the stationary phase
  • The mobile phase interacts with the sample components differently based on their properties
  • This differential interaction leads to the separation of the sample components
• How does the interaction between the mobile phase, stationary phase, and sample components lead to the separation of the sample in chromatography?

  The different sample components have varying affinities for the mobile and stationary phases, causing them to move through the system at different rates and separate
• What causes the separation of components in chromatography?

  Affinity for phases
• What is the name of the first step in column chromatography shown in the image?

  Loaded sample
• What are the key factors that affect the resolution and efficiency of chromatographic separation?

  • Choice of mobile and stationary phases
  • Flow rate of the mobile phase
  • Temperature
  • Sample concentration and volume
• What are the two possible states of the stationary phase?

  Solid or liquid-coated solid
• What is the primary principle behind chromatography?

  Separation by affinity
• What is the purpose of the stationary phase in column chromatography?

  To separate the components of the loaded sample
• What is the name of the chromatography technique shown in the image?

  Column chromatography
• How does the stationary phase in chromatography affect the separation of sample components?

  • The stationary phase contains a material that interacts with the sample components
  • The different sample components have different affinities for the stationary phase
  • This causes the components to move through the stationary phase at different rates, resulting in separation
• What type of material is used as the stationary phase in paper chromatography?

  Filter paper strip
• What are the main steps of column chromatography shown in the image?

  1. Loaded sample
  2. Mobile phase sample separation
  3. Stronger interactions
  4. Fractions collection
  5. Eluted molecules
• Steps to calculate the Rf value

  1️⃣ Measure the distance the substance has moved

  2️⃣ Measure the distance the solvent front has moved

  3️⃣ Divide the substance distance by the solvent distance
• The mobile phase can only be a liquid.

  False
• Substances with a stronger affinity for the stationary phase move faster in chromatography.


  False
• How is chromatography used in forensics?

  Analyzes evidence at crime scenes
• What are three applications of chromatography in medicine?

  Identify, purify drugs, monitor levels
• What is the purpose of the Rf value in chromatography?

  Identify substances