Preparation of samples:

• Use a pestle and mortar to crush the Aspirin tablet and transfer to a weighing boat or bottle

• Dissolve approximately 0.1g of the powdered tablet in 0.5cm³ of Ethanol

• Repeat these steps with the Ibuprofen tablet and the Paracetamol tablet

• Use a pestle and mortar to crush the Caffein tablet and transfer to a weighing boat or bottle

• Dissolve approximately 0.1g of the powdered tablet in 7.0cm³ of Ethanol

• Repeat these 2 steps with the Anadin Extra tablet

Thin-layer chromatography

Preparation of samples:

• Carefully use a pencil to draw a faint line 1cm above the bottom of a TLC plate and mark five spots, equally spaced along the line

• Use a capillary tube to apply a tiny drop of each solution to a different origin spot and allow the plate to air dry

• Add approximately 10cm³ of Ethyl Acetate to the chromatography tank

• Place the TLC plate into the Chromatography tank, making sure that the level of the solvent is below the spotting line. Place the lid on the tank and make sure it is a tight fit.

• When the level of the solvent reaches about 1cm from the top of the plate, remove the plate and mark the solvent front with a pencil. Allow the plate to dry in the fume cupboard

• Place the plate under a UV lamp in order visualise the spots. Draw around them lightly in pencil

• Calculate the Rf values of the observed spots

Calculating Rf  values:

Rf   =