Lab 1: Identification of Analgesics by Serina Lewis

Purpose: To learn why drug purification is important and how to purify drugs.

Introduction: This experiment will provide a positive identification of a drug and possibly will determine how much the drug is present. Thin-layer chromatography (TLC) is a sensitive, fast, simple, and inexpensive analytical technique used in carrying out organic experiments, and also widely used in crime labs. TLC is used by criminalist for drug identification to determine the number of components in a mixture, to determine the identity of two substances, to monitor the progress of the reaction, and to determine the degree of purity.

Materials and Methods: Sample 4 and 7 (1%solution), ethyl acetate and acetic acid were the solvents in the experiment.Iodine & a UV lamp were used to identify the spots. TLC plates, made of silica, were cut into 25 x 5 cm plates (used a ruler) , and a beaker with a watch glass on top.

Procedure: A 1 cm line was drawn from the bottom of the TLC plate using a pencil and a ruler. A capillary tube was used to spot the sample onto the TLC plate at the 1 cm line. The TLC plate and filter paper was placed in a beaker that contained ethyl acetate or ethyl acetate and acetic acid and then covered with a watch glass. Once placed into the beaker, the TLC plate became saturated with the solvent vapors. The wet TLC plate was removed from the beaker after the solvent and allowed to dry on a Kim wipe. In order to view the spots, the dried TLC plate was viewed by a UV lamp then placed into a beaker with iodine.

Results

The results indicated as follows:

Figure 1, on the right, the TLC plate with sample 4 and 7

Sample 4 had an Rf value of 0.45

Sample 7 had an Rf value of 0.53

Discussion/Conclusion: Based on the results, sample 4 is purified, while sample 7 is not.

-Serina Lewis

Biology Class of 2011