SIMPLE CHROMATOGRAPHY 1 Separating a liquid mixture.

PHOTOGRAPHY 2 Photography is the science and art of photos and Chromatography is the science or study of chromatograms. A chromatogram is similar to a photo that shows how a mixture has been separated into its different coloured parts.

EXAMPLE OF A CHROMATOGRAM This shows a typical chromatogram after it has been made/prepared /developed. If you look closely this mixture has been separated into 5(FIVE) different parts or components. 3 Image souce: Natrij at English WikipediaWikipedia

Background to Chromatography 4 Chromatography is used to separate mixtures of substances into their components. All forms of chromatography work on the same principle. They ALL have a STATIONARY PHASE( a solid, or a liquid supported on a solid) and a MOBILE PHASE ( a liquid or a gas).

How chromatography works 1. The MOBILE PHASE flows through the STATIONARY PHASE and carries the parts /components of the mixture with it. 5

How chromatography works 2 6 Different components travel at DIFFERENT RATES. The REASONS for this will be looked at further on, in another lesson.

PAPER CHROMATOGRAPHY 7 In PAPER CHROMATOGRAPHY, the STATIONARY PHASE is a very good absorbent paper. The MOBILE PHASE is a suitable LIQUID SOLVENT or mixture of solvents.

WHAT YOU ARE GOING TO USE PAPER CHROMATOGRAPHY FOR ? 8 To SEPARATE out MIXTURES of coloured dyes in particular inks contained in felt tip pens. You can chose your favourite colour or any other and one other PRIMARY colour. Before we start our experiments we have to think a little about our COLOURS.

PRIMARY COLOURS 9 Are RED, YELLOW and BLUE Image source: Jason on Flickr, shared underJason on Flickr

READY TO START RUNNING YOUR PAPER CHROMATOGRAPHY 10 Have fun and listen to all your INSTRUCTIONS before you start. You have worksheets to help record and write your observations. All SCIENTISTS have to write what they have observed during their experiments. They should also try to explain what they have observed and WHY it happened or why what they EXPECTED to happen DID NOT.

THANK YOU FOR LISTENING 11 Image: George Johnston

GLC, HPLC and Industrial and other uses of Chromatography. The science of separating mixtures. 12 More Advanced Chromatography

Reminder how it works Paper Chromatography Solvent 2.Paper 3.Mixture 4.Separate Colours 5.Solvent Front 6.Immersion line Image souce: WikipediaWikipedia

How do the different components travel at different rates? 14 Several factors explain why the different parts of the mixture separate out as they do:- Solubility Molecular Weight Polarity

SOLUBILITY 15 If the mixture components are soluble in the solvent being used, the mixture will be carried up the paper strip. The material in the mixture will dissolve as the solvent front moves through it. Some of these substances will likely be more or less soluble than others. The more soluble substances will move faster and to a greater distance than those that are less soluble.

Molecular Weight 16 Those substances of lighter molecular weight will move higher up the paper. Those substances having a higher molecular weight will separate lower down the paper.

POLARITY 17 The chromatography paper is made of cellulose, a polar substance. If the compounds within the mixture are non-polar they will travel further. More polar substances bond(stick) with the cellulose paper more quickly, and therefore do not travel as far.

OTHER FORMS OF CHROMATOGRAPHY 18 TLC:- Thin layer Chromatography: Uses a thin layer of a solid phase spread onto a sheet of plastic or glass. GLC:- Gas Liquid Chromatography: Uses a GLC Instrument/Machine, which involves passing a gas through a glass or steel column coated with the solid phase. HPLC:- High Performance Liquid Chromatography: Uses even more sophisticated HPLC Instruments/Machines similar to GLC and involving higher gas pressures.

Basic GLC Instrument Diagram 19 Image Source: WickipediaWickipedia

LABORATORY GLC INSTRUMENT 20 Image Source: WickipediaWickipedia

HPLC 21 Image Source: Dvstechnique on WickipediaWickipedia

HPLC INSTRUMENT 22 Image Source: WickipediaWickipedia

INDUSTRIAL APPLICATIONS/USES OF CHROMATOGRAPHY 23 CHROMATOGRAPHY of many kinds is used throughout the chemical industry. Environmental testing labs test for contamination. Such as PCBs in waste oil. Pesticides such as DDT in groundwater. The EPA uses it to test DRINKING WATER. And to monitor AIR QUALITY.

MORE INDUSTRIAL USES OF CHROMATOGRAPHY 24 Pharmaceutical companies use it prepare large quantities of extremely pure drugs. Also to test the purified compounds for trace contaminants. It is used for quality control in the food industry. By separating and analysing additives, vitamins, preservatives, proteins and amino acids.

POLICE FORENSIC SCIENCE USE OF CHROMATOGRAPHY 25 To look for traces of flammable chemicals in burned material from possible arson sites. To test for class A illegal drugs in blood and urine samples from suspect drug users and criminals. To separate and test for DNA in exhibits produced in evidence.

Acknowledgements 26 Chromatography by George Johnston, The Children’s Hospital School, Leicester is licensed under a Creative Commons Attribution 4.0 International License.Creative Commons Attribution 4.0 International License