6.5 Chromatography and Spectroscopy Flashcards
What is chromatography ?
Used to separate individual components from a mixture of substances.
What is the stationary phase ?
Does not move and is normally a solid or liquid component supported on a solid.
What is the mobile phase ?
Moves and is normally a liquid or a gas.
What is thin layer chromatography ?
Quick and inexpensive analytical technique that indicates how many components are in a mixture.
What does TLC used ?
Uses a silica plate, which is highly adsorbant.
What is adsorption ?
Process by which the solid silica hold the different substance in the mixture to its surface. Separation is achieved by the relative adsorptions of substances in stationary phase.
What is the retention factor ?
distance moved by solute / distance moved my solvent front
What is gas chromatography ?
Used for separating and identifying volatile organic compounds present in a mixture.
What is the stationary phase is gas chromatography ?
High boiling point liquid on an inert solid support.
What is mobile phase in gas chromatography ?
Inert carrier gas such as helium.
How does gas chromatography work ?
Volatile mixture is injected into apparatus. Mobile carrier gas carries components in sample through capillary column which contains liquid stationary phase.
How are components separated in gas chromatography ?
Dependent on their solubility in stationary phase. They reach detector at different times.
What is retention time ?
Time taken for each component to travel through the column.
How is concentration of components compared ?
Determined by comparing its peak integration with values obtained from standard solution of the components.
