course note
Experiment 10 Thin Layer Chromatography
Purpose!
To identify how many components are in a mixture and the identity of a compound in a mixture by comparing the Rf of a known compound with the Rf of an unknown compound.
Intodection.
In this experiment the thin-layer chromatography the (TLC) will be used to determine the composition of various over-the-counter analgesic. We will be given two commercially prepared TLC plates with a flexible backing and a silica-gel coating with a fluorescent indicator. On the first TLC plate, a reference plate, we will spot five standard compounds . In addition, a standard reference mixture containing four of these same compounds will be spotted. In this experiment we will not be using Ibuprofen because it would overlap with salicylamide after the plate is developed.On the second plate (the sample plate), you will spot Naproxen sodium as an additional standard and four commercial analgesic preparations in order to determine their composition. Two methods of visualization will be used to observe the positions of the spots on the developed TLC plates. First, the plates will be observed while under illumination from a short-wavelength ultraviolet (UV) lamp
For a second means of visualization, iodine vapor will be used
Hypothesis
I predict that the polar substance will be close to the surface but ,the nonpolar substance will move along with the solvent.
Reaction /setup.
Reagent>>
Reagent
Molar mass
Poiling point
Melting point
Density
Refractive index
Safety Data methylene chloride
84.94 g/mol
40 C
-97C
1.325g/cm3
Flammable
Ethanol
46.07g/mol
78.3C
-117.3C
789.0kg/m3
Flammable
Acetaminophen
151.16g/mol -------
169-172C
1.263g/cm3
Aspirin
180.16g/mol
140C
135C
1.35kg/m3
Caffeine
194.19
178C
235-238C
1.23g/cm3
Ibuprofen
156.13g/mol
157C
75-78C
1.03g/cm3
Salicylamide
137.136g/mol
181C
142C
1.33g/cm3
Purpose!
To identify how many components are in a mixture and the identity of a compound in a mixture by comparing the Rf of a known compound with the Rf of an unknown compound.
Intodection.
In this experiment the thin-layer chromatography the (TLC) will be used to determine the composition of various over-the-counter analgesic. We will be given two commercially prepared TLC plates with a flexible backing and a silica-gel coating with a fluorescent indicator. On the first TLC plate, a reference plate, we will spot five standard compounds . In addition, a standard reference mixture containing four of these same compounds will be spotted. In this experiment we will not be using Ibuprofen because it would overlap with salicylamide after the plate is developed.On the second plate (the sample plate), you will spot Naproxen sodium as an additional standard and four commercial analgesic preparations in order to determine their composition. Two methods of visualization will be used to observe the positions of the spots on the developed TLC plates. First, the plates will be observed while under illumination from a short-wavelength ultraviolet (UV) lamp
For a second means of visualization, iodine vapor will be used
Hypothesis
I predict that the polar substance will be close to the surface but ,the nonpolar substance will move along with the solvent.
Reaction /setup.
Reagent>>
Reagent
Molar mass
Poiling point
Melting point
Density
Refractive index
Safety Data methylene chloride
84.94 g/mol
40 C
-97C
1.325g/cm3
Flammable
Ethanol
46.07g/mol
78.3C
-117.3C
789.0kg/m3
Flammable
Acetaminophen
151.16g/mol -------
169-172C
1.263g/cm3
Aspirin
180.16g/mol
140C
135C
1.35kg/m3
Caffeine
194.19
178C
235-238C
1.23g/cm3
Ibuprofen
156.13g/mol
157C
75-78C
1.03g/cm3
Salicylamide
137.136g/mol
181C
142C
1.33g/cm3