1. Chromatography

2. What is Chromatography?
Chromatography is a technique for separating mixtures in order to analyze and identify the components of a mixture.
Separate
Analyze
Identify
Mixture
Components

3. Uses for Chromatography
Real-life examples of uses for chromatography:
Pharmaceutical Company – determine amount of each chemical found in new product
Hospital – detect blood or alcohol levels in a patient’s blood stream
Law Enforcement – to compare a sample found at a crime scene to samples from suspects
Environmental Agency – determine the level of pollutants in the water supply
Manufacturing Plant – to purify a chemical needed to make a product

4. How Chromatography Works
Paper chromatography separates the components of a mixture by their different attractions to the solvent and the paper.
The mixture is placed on the paper
The solvent moves up the paper
The solvent dissolves the components in the mixture
The solvent carries the individual components up the paper, to a height that depends on their attraction to both the solvent and the paper.

5. Diagram of Chromatography
Paper
Separation
Solvent
Mixture
Components
Components
Attraction to Paper
Attraction to Solvent
Blue
Insoluble in Mobile Phase
Black
     
 
Red
    
Yellow 
        

7. Paper Chromatography Series of spots forms. Each spot corresponds to a
different chemical in the
mixture.

8. Separation and identification.
Measure Rf values of Coloured compounds & colourless compounds.
Compare samples in mixture with known substances.
For Colourless compounds ‘ Locating Agents’ are used

9. What real chromatograms look like1 2 3 4 5
Each picture shows the chromatogram at a later time

10. Types of Chromatography
Paper Chromatography – separates dried liquid samples with a liquid solvent and a paper strip
Liquid Chromatography – separates liquid samples with a liquid solvent and a column made of solid beads
Gas Chromatography – separates vaporized samples with a carrier gas and a column made of a liquid or of solid beads
Thin-Layer Chromatography – separates dried liquid samples with a liquid solvent and a glass plate covered with a thin layer of alumina or silica gel.