A chemist runs a thin-layer chromatography plate and marks the
solvent as having traveled 6.1 cm up the plate. After
visualization, the distance of the spot of interest is measured as
having traveled 2.7 cm. Select the correct Rf value of this
spot
Thin Layer Chromatography utilizes a glass or metal plate coated
with a thin layer of absorbent material such as silica gel. The
sample is prepared similiarto paper chromatography and a solvent is
used to elute the sample.
1. Which is the stationary phase? Plate Silica
Gel Solvent
2. Which is the mobile phase? Plate Silica
Gel Solvent
3. Which component is inert? Plate Silica
Gel Solvent
What would happen if you ran a flash (chromatography) column
using a solvent where the Rf fo the lower spot was 0.5?
What would happen if you ran a flash column where the Rf value
of the upper spot was .2 and the Rf value of the lower spot was
.05?
Compare and contrast Column (solid-liquid) chromatography, Paper
Chromatography, and thin layer chromatography in respect to the
size of the sample that can be separated, the ease of use, and the
versatility of the method.
Questions regarding Thin Layer Chromatography Analysis
(TLC):
1. What is the purpose of the wick?
2. Why is it important to use diluted solutions?
3. Why is it important to spot the TLC plate quickly and
lightly?
4.What solvent will use to develop your TLC plates? ethyl
acetate, hexanes, or some mixture of the two? Why?
5. List at least 3 common errors when performing TLC and how to
fix them.
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.