Thin Layer Chromatography and Column Chromatography Essay

2564 Words Oct 12th, 2012 11 Pages
Introduction
Chromatography is a technique used to separate a mixture into its individual components. In this experiment, chromatography is done by using a thin layer chromatography (TLC) plate and filter paper. The word ‘chromatography’ itself means the separation of colours. However, nowadays, both coloured and colourless compound are used in chromatography by various methods.
In chromatography, the separation process of mixture is mainly based upon the polarity and molecular weight of sample. Then, the separation involves mobile phase and stationary phase. The mixture to be separated is applied to an immovable solid surface, which is the stationary phase, such as TLC plate and the filter paper. Then, suitable solvent is then added to
…show more content…
3. Set up of apparatus as shown in Diagram 2:
(note: the glass column was clamped in a vertical way)
While setting up the apparatus, 15 mL of solvent was poured in before decanting the slurry. The solvent was then drained to make the slurry to become packed. The drained solvent was collected in collection flask, and poured into the glass column again and again for 5 times to allow packing. During the 5th time, when the solvent level is within 6cm of the top of the adsorbent, add 0.5 cm of sand layer on the slurry. The excess solvent was drained off until its level is exactly above the lower layer of sand and the stopcock was closed.
Diagram 2
Diagram 2
Sand (0.5cm)
)
Sand (0.5cm)
)
cotton cotton Sand (0.5cm)
Sand (0.5cm)
Slurry
Slurry

4. The mobile phase was added slowly into the glass column. (The mobile phase is mixture of 0.01g of p-nitroanilinie and 0.01g pyrene, which dissolved as much as possible in minimum amount of ethyl acetate). 5. Drain off the remaining solvent until the mixture solution is just below the top layer of sand. 6. The wall of glass column was rinsed with fresh solvent and drained until the level is once again below the top of sand. 7. The rinsing was repeated until the silica gel was virtually colourless. 8. The column was then filled with fresh solvent 9. Separation of band was observed as column developed. The lower band is colourless, which was collected in another collection

Related Documents