Thin-Layer Chromatographic Analysis of Drug Components

Thin-Layer Chromatographic Analysis of Drug Components

Introduction

The purpose of this lab was to identify an unknown drug by using chromatographic analysis. This form of analysis required that the components of an analgesic drug tablet be tested before and analyzed before the testing of the unknown drug. Through the information gathered during the experiment and the textbook information the unknown drug was fairly simple to identify. This process of chromatographic analysis is used by lab technicians in hospitals who are encountered with the challenge of identifying a drug that is unknown at the time ( Lehman,John 2004). This process is similar to the ones performed in toxology labs when trying to identify a drug that has been taken by the patient, this is important so that the physician could act according to the patients well-being. For this experiment, analyses of components of popular drugs were required before we were presented with an unknown to analyze.

Procedure and Observations

To begin with, five individual spot samples of known drug components were spot tested. Each individual component was spot tested on a TLC plate. The TLC plate was prepared by drawing five evenly spaces marks running horizontal on about one centimeter from the base of the plate. Each sample was taken by a micro pipette and a small dot of each of the samples was spotted right above the marks on the TLC plate. The five samples that were spotted on the TLC included ( Caffeine, Aspirin, Ibuprofen, Salicylamide, and Acetaminophen). Following the spotting of each component the developing chamber for the TLC plate was prepared.

The developing chamber was constructed my obtaining a mason jar and filling it about a centimeter filled with the developing solution. Dichloromethane was chosen for the developing solution and the desired amount was poured into the mason jar. After the Developing chamber was prepared, the spotted TLC plate was placed into the solution on a slant so that the whole plate was in the jar. The lid was placed on the mason jar and time allowed for the plate to absorb the dichloromethane. During the development time it was crucial that the absorbed liquid did not over shoot the top of the TLC plate.

After the development, the TLC plate was removed and was carefully placed under an ultraviolet. Due to each of the samples containing a fluorescent indicator, the spots are easily spotted on the developed TLC plate by showing up as dark spots. Each spot was marked with a pencil and the measurements of how far each spot moved during the development was taken in millimeters. After each components distance traveled was taken, each R_f value was taken for each of the components was taken.

The R_f value for each of the tested components were taken by measuring how far the spot traveled. Starting at the marks at the