(i)To learn the technique of TLC and the visualization of colourless components.
(ii)Identify the unknown drug by a TCL comparison with standard components.
Part2 :to learn the separation technique by using TLC plate in separating a mixture of compound by using spinach leaf.
Apparatus:UV lamp,capillary ,250 ML beaker
Materials:aspirin,acetaminophen,caffeine,unknown A,unknown B,TLC plates,ethyl acetate,Hexane,acetic acid,iodine
A.spotting of the TLC plates
1.A TLC plates is obtained from my instructor.
2.the plate is set down on a clean,dry surface then a line Is drawn lightly across the plate about 1cm from the bottom of the plate with the aid of a 2B pencil as shown in figure 3(i).
3.next five 2-3mm lines make,about 0.8cm is spaced apart and running perpendicularly through the lines across the bottom of the TLC plate.
4.The plate is spotted with 5 different analgesic.A separate capillary tube is used for each sample.The acetaminophen solution is first spotted,then the caffeine,then the unknown A,then aspirin,and lastly the unknow B.
B.Developing the TLC plate
1.A developing chamber is prepared as indicated in figure 3(ii),a 250mL beaker is used as a chamber,a half piece of filter paper inside,and aluminium foil to cover.
2.the eluent ,2:1 mixture of ethyl acetate:hexane is poured,into a beaker to a depth of under 1cm(about 15mL).About 5 drops of acetic acid is added into the beaker and mixed.The prepared TLC plate is placed in the developing chamber,the solvent level is ensured below the pencil line.
3.after the solvent has risen to near the top of the plate(about 0.5cm from the top),the plate is removed and the solvent front is marked with a pencil.the solvent is allowed to evaporate from the plate in the fumehood.
1.the colourless compounds are visualized by illuminationof the plate with an ultraviolet(UV)lamp.
2.the spots are outlined with a 2B pencil.the