Question

Name some possible sources of error that could occur during a 'Thin Layer Chromatography Analysis of Analgesic Drugs' laboratory. Briefly discuss how these would effect your results.

Answer 1

If you don't add enough sample to the plate, you won't be able to see the spot. If your solvent is too polar or not polar enough, you will get poor separation between chemicals because many chemicals will either move with the solvent or not move with the solvent (depending on their polarity and the solvent polarity), but will not be separated from each other.

There are many human errors that could occur as well, such as not marking the bottom of the plate (where the samples are placed) or the solvent front after running, which could create measurement errors. If the plate is touching the sides of the container or if it is not square, this could create problems where the solvent does not travel uniformly up the plate so the lanes would be skewed to one side or the other.

When the TLC plate was placed in a beaker, and filled with solvent, a drop of solvent fell on to the plate, could have caused slight differences in the distances obtained for the mixture. It could have also caused the final smear to appear less distinguished into individual components. Careful filling of the beaker with solvent could have avoided this error.

One significant source of error has been shown to arise from hand spotting of small volumes of solution when preparing the initial spots

There are probably many more you could come up with.