Have you ever wondered how many dyes a pen ink consists of?

Our IGCSE students conducted a simple chromatography experiment to separate the colours of various inks. They used common laboratory apparatus and reagents such as beakers, filter papers, measuring cylinders, funnels and ethanol, as well as pen inks, scissors, pencils, rulers and aluminium foil. Firstly, they had to draw a 5.2 cm x 11 cm rectangle shape on two filter papers using a pencil and then cut them out. Following that, they drew the baseline at a distance of 1 cm from the bottom of each filter paper using the pencil and placed spots of different inks on the baseline. They then measured 6-7 mL of ethanol using the measuring cylinder, transferred it into a beaker and sealed the beaker using a piece of aluminium foil, for 5 minutes.  The filter papers with the spots of inks were placed in the beaker in an upright position and immersed into ethanol, so that the baseline was above the level of the solvent. The beaker was quickly re-sealed and the solvent (ethanol) diffused across the filter papers, carrying along the various components of each ink and separating them according to their different solubilities. The experiment ended when the solvent reached about 1 cm from the top of each filter paper. Our students learned how chromatography can be used as separation technique in a simple experimental setting, as well as the wider applications, and developed their own laboratory skills in a fun and interactive way through the process.img_20181115_141939img_20181115_142012img_20181115_142038img_20181115_142103img_20181115_142230img_20181115_142255img_20181115_142320img_20181115_142349img_20181115_142416img_20181115_142447

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