Chromatography Flashcards
What is chromatography?
A technique used to separate components of a mixture based on their molecular properties
On what principle does chromatography work?
Different substances move at different speeds through a medium, depending on their affinity to the mobile and stationary phase
What are the mobile and stationary phase?
Mobile phase: the liquid or gas that carries the substances
Stationary phase: the solid or liquid that the mobile phase moves through
How does chromatography separate substances?
Components partition differently between the mobile and stationary phases, leading to separation
What are the main types of chromatography?
Paper chromatography, thin layer chromatography (TLC), gas chromatography, and liquid chromatography
What is paper chromatography?
A technique using absorbent paper as the stationary phase and a liquid solvent as the mobile phase
What is thin layer chromatography (TLC)?
Similar to paper chromatography, but uses a plastic/glass plate coated with silica gel or alumina as the stationary phase
What is gas chromatography?
A method using a gas mobile phase and a solid/liquid stationary phase inside a column
What is liquid chromatography?
A method where a liquid mobile phase carries substances through a column filled with a stationary phase
What is a chromatogram?
A visible record of separated substances in a mixture
What does each spot or band on a chromatogram represent?
A separate substance in the mixture
What is an Rf value (Retention factor)?
A ratio of the distance a substance moves of the distance the solvent moves
How can Rf values be used for identification?
Similar substances have similar Rf value values under identical conditions, allowing comparison with known values
How is chromatography used in forensics?
To analyze ink samples, drug traces, and other crime scene evidence
How is chromatography used in the food industry?
To detect contaminants and check food authenticity
How is chromatography used in pharmaceuticals?
To separate an analyze drug components, ensuring purity and safety
How is chromatography used in environmental monitoring?
To detect pollutants in air, water, and soil samples
What is the calculation for the Rf value?
Rf = distance traveled by the substance / distance traveled by the solvent
