Thin Layer Chromatography Lab Report

Introduction

The purpose of this experiment was to identify the composition of over-the-counter analgesics by the method of Thin Layer Chromatography (TLC). The TLC method is used for rapid qualitative analysis of mixtures to determine and identify its components and purity. A development solvent was used to separate the analgesics found in both the known drug sample and an unknown sample of over-the-counter medications. The pertinent techniques for this experiment are spotting the stationary phase with the samples, placement of stationary sample in mobile phase chamber for development, observation under a UV light, and further development in iodine chamber.

Experimental Scheme

Figure 1 Figure 2

Anacin Salicylamide

Procedure

12 micropipettes were prepared in lab by heating the middle of capillary tubes over a flame. The capillary tubes

After the completion of the micropipettes preparations, two silica TLC plates were prepared by drawing a line 1 cm from the edge of the silica TLC paper and divided into five parts with a ruler and a graphite pencil. One of the prepped silica TLC was used as the Reference Plate and the second as the Unknowns plate. The reference plate was spotted with Acetaminophen, Aspirin, Caffeine, Safinamide, and the standard reference mixture. The Unknowns plate was spotted with solutions identified as solution 1 through 4 and the last spot was spotted with the standard reference mixture. The micropipettes were used for spotting the two silica TLC plates after each was dipped in a separate solution. Effort was made to avoid over spotting or cross contamination of the solutions. Both prepped silica TLC plates were placed in the Development Chamber (DC), that had 0.5% glacial acetic acid in ethyl acetate as solvent.