how will you use simple filter paper to demonstrate chromatography. Explain with diagram
Answers
Answer
Paper chromatography is a legitimate though primitive form of chromatography but it can be used as a model to talk about all types. A sample spot of black ink can be applied near the bottom edge at a marked location. The edge is dipped in solvent ( a bit of trial and error here) maybe methanol. A covered chamber can be used to house the experiment, making it more reproduceable. Wait some minutes until the solvent front reaches near the top of the paper. The ink should separate into component colours. Take out the paper and quickly mark the solvent front before it dries. You can measure the height of the ink spots above the orgin and compare with the solvent front for the Rf value.
This can also be used as a model for other forms of chromato
graphy as there is
a stationary phase - paper - mainly cellulose
mobile phase - solvent - methanol or similar
sample - ink spot
results - Rf values for each spots
results - intensity of spot increases with concentration
results- compare with spots of known concentration.
So HPLC would have a different list 1–6 but still within the model
1 stationary phase - steel column- usually modified C18 silica
2 mobile phase - solvent mixture or gradient - acetonitrile or methanol/water delivered by a pump
3 sample - dissolved mixture - applied using a valve and loop
4 results - peaks from the detector - on PC integration system
5 results - area under each peak - proportional to concentration
6 results - calibration against know standards - numerous software based methods
Explanation:
REQUIREMENTS
Large glass jam jar with cover (eg flat piece of plastic or glass)
6 sharpened wooden sticks (ie toothpicks)
Hair dryer or warm oven
Ruler
Stapler
Scissors
Sellotape
Paper clips
Cotton thread
Lollipop sticks
Pencil
Sheet of chromatography paper, or large filter paper
0.1% aqueous sodium chloride solution (mobile phase)
Distilled water
Pack of assorted food colours (red, yellow, green and blue)
Small test tubes
Labels
METHODS
EXTRACTION OF THE COLOURS
Sort the ‘Smarties’ into piles of the same colour. Tip one of the piles into a small clean test tube and to the ‘Smarties’ add a small quantity of cold distilled water (approx 1cm3). Agitate the test tube and its contents for 2 minutes until the colour appears in the aqueous phase. Decant the coloured solution into a clean dry test tube. Label the tube and its contents with name of the ‘Smarties’ colour.
Repeat the extraction process for each pile of ‘Smarties’.