Lab.1. Thin-layer chromatography
REPORT
NAME…………………………………………..
FIRST NAME:…………………………………………….
STUDENT GROUP……………………………………..
DATE OF LABORATORY………………………………
PART I
ELUOTROPIC SERIES OF SOLVENTS IN SYSTEM WITH SILICA GEL
Table.1. The values of migration distance (mm) and retardation factor, RF, of solutes in systems with silica gel and different solvents, is the elution strength
Hexane Toluene Acetone Solute = 0.00 = 0.22 = 0.56 The solvent front migration distance, start – finish (b) Migration RF Migration RF Migration RF Colour of the distance distance distance dye (a) (a) (a)
Dye 1
Colour …….
Dye 2
Colour…….
Dye 3
Colour …….
Dye 4
Colour ……
Mixture
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Lab.1. Thin-layer chromatography
Formula to use:
RF = a/b, RF – retardation factor
Answer the questions:
Which solvent is characterized by the highest elution strength? Arrange the eluotropic series for solvents/eluents used.
What components comprise the investigated sample mixture?
Table 2. The values of separation factor, α, of solutes chromatographed in systems with silica gel and different solvents, is the elution strength
Hexane Toluene Acetone Solute = 0.00 = 0.22 = 0.53
Separation factor Separation factor Separation
factor
Dye 1/ Dye 2
Dye 2/ Dye 3
Dye 3/ Dye 4
Formulas to use:
Place for calculations:
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Lab.1. Thin-layer chromatography
Answer the questions:
Indicate chromatographic system, which is characterized by the highest values of separation factor?
Indicate the chromatographic system, which facilitates good separation of all investigated mixture components.
PART II.
ELUOTROPIC SERIES OF SOLVENTS IN TLC SYSTEMS WITH ALUMINUM OXIDE
Use the procedure from PART I, steps 1- 6, for aluminium oxide plates.
Table.3. Migration distance (mm) and retardation factor, RF, values of solutes in systems with aluminium oxide and different solvents; is the elution strength
Hexane Toluene Acetone Solute = 0.00 = 0.29 = 0.56
The distance of solvent front migration, start – finish (b)
Migration RF Migration R Migration R Colour of the F F distance distance distance dye (a) (a) (a) Dye 1 Colour ……. Dye 2 Colour……. Dye 3 Colour ……. Dye 4 Colour ……
Mixture
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Lab.1. Thin-layer chromatography
Answer the questions:
Which solvent has the highest elution strength? Arrange the eluotropic series of solvents for chromatographic systems with aluminium oxide.
Table 4. Separation factor, α, values of solutes in systems with aluminium oxide and solvents/eluents specified
Formulas to use:
Hexane Toluene Acetone Solute = 0.00 = 0.29 = 0.56
Separation factor Separation factor Separation
(α) (α) factor (α)
Dye 1/ Dye 2
Dye 2/ Dye 3
Dye 3/ Dye 4
Answer the question:
For which solvent the separation factor shows the highest values?
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Lab.1. Thin-layer chromatography
PART III
COMPARISON OF ELUTION STRENGTH OF SOLVENTS IN SYSTEMS WITH SILICA AND ALUMINA
Table.5. The values of retardation factor, RF, obtained for the systems with silica gel and aluminium oxide
Hexane Toluene Acetone
Silica Aluminium Silica Aluminium Silica Aluminium Solute oxide gel gel gel oxide oxide
Dye 1
Colour …….
Dye 2
Colour…….
Dye 3
Colour …….
Dye 4
Colour ……
Mixture
Answer the question:
Have you obtained the same results for the systems with silica gel and aluminium oxide ? If not then try to explain the difference/s?
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Lab.1. Thin-layer chromatography
PART IV
ELUTION STRENGTH OF MIXED SOLVENTS IN SYSTEMS WITH SILICA GEL
Table 6. Migration distance (mm) and retardation factor values of investigated solutes in the systems with silica gel and acetone + hexane
Eluent 5% acetone in hexane 10 % acetone in hexane 40% acetone in hexane
The migration distance of solvent front (start – finish) (b) Migration RF Migration RF Migration RF Colour of the dye distance (a) distance (a) distance (a)
Dye 1
Colour …….
Dye 2
Colour…….
Dye 3
Colour …….
Dye 4
Colour ……
Colour of the dye
Answer the question:
Does composition of the mobile phase influence on migration distance of solute zone/s?
Arrange the solvent mixtures/solutions in respect of their elution strength in silica gel system
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