TLC Limit Test for Related Substances

 
TLC Limit Test for Related Substances
Objective
To test Naproxen Tablet Using Thin Layer Chromatography Limit Test
Materials
• Naproxen tablets
• Toluene
• Tetrahydrofuran
• Methanol
• Acetic Acid
Introduction
Naproxen is (+) –2-(6-methoxyl-2-naphthyl)-propionic acid. Naproxen falls into a
category of compounds known as non-steroidal anti-inflammatory drugs (NSAIDS), is very
light sensitive and together with its derivative compound, Naproxen Sodium, is used for making
pain and fever relieving drugs. The Naproxen drugs are also very effective in treating stiffness
and inflammation caused by ailments like kidney stones. Figure 1, below, shows the structure of
naproxen, which has the formula C14H14O3.
Figure 1
Procedure
The average weight of the tablets was first determined, after which ten tablets were taken
from the lot, weighed and ground into powder form. The next step involved following the
procedure for thin-layer chromatography, wherein silica gel GF254 is used as coating and a
blend of toluene, 18 volumes of tetrahydrofuran and 6 volumes of 6 M acetic acid as the mobile
phase. 10 µL of methanol solution, containing 2.0 per cent w/v of Naproxen solution (1), was

applied to the chromatoplate. In the same way, 10µ methanol solution, containing 0.010 per cent
w/v of Naproxen solution (2), was applied to the chromatoplate. The chromatoplate was then
taken out and allowed to dry. It was then examined under an ultraviolet lamp with a maximum
output of 254 nm.
Calculations
RF = a∕b where a = weight of sample way
 b = weight of mobile phase way
b = 13.5
Rf1 = a/b = 5.1/13.5 = 0.378
Rf2 = 4.9/13.5 = 0.363
Rf3 = 4.3/13.5 = 0.319
Rf4 = 4.4/13.5 = 0.326
Results and Discussion
Number of sample B A Rf
1 13.5 4.4 0.33
2 13.5 4.3 0.32
3 13.5 4.9 0.36
4 13.5 5.1 0.39
In the Naproxen analysis, the TLC method was used. This method is a liquid-solid
technique. It involves the mobile phase moving up the thin layer of the stationary phase through
the action of the capillaries. The TLC technique has a comparable correlation with column
chromatography, which involves the solvent passing through the absorbent column. This
association enables TLC to be a faster technique for establishing the composition of solvents for
preparative separations. For the separation to be successful, the sample must possess a fairly
equal affinity for solvent and packing material. The sample will not move from the origin, if the
sample possesses a greater attraction to the stationary phase than the solvent, resulting in a low
Rf value. Effective removal of the solution can be achieved by optimizing the relative affinity of
sample, solvent and support. 

Conclusion
Naproxen is (+) –2-(6-methoxyl-2-naphthyl)-propionic acid. It’s from a category of
compounds known as non-steroidal anti-inflammatory drugs (NSAIDS). It’s very light sensitive
and should be shielded from it. Together with its derivative compound, Naproxen Sodium, it’s
used for making pain and fever relieving drugs. The Naproxen drugs are also very effective in
treating stiffness and inflammation, brought about by ailments like kidney stones. The formula
for Naproxen is C14H14O3.