Introduction Separation, a process by which the distinguishing between substances through physical or chemical means in a mixture may be carried out. A widely employed technique for this purpose is called chromatography. 1 There are many different types of chromatography, including gas-liquid, paper, column and so on. 1 Chromatography differentiates by allowing the differences in polarity, vapor pressure, solubility and so on of different substances to be observed. 1 In our endeavor, we will be using specific types of chromatography, termed Thin-Layer Chromatography (TLC) and column chromatography. Essentially, TLC is an adsorption aspect of chromatography that uses a polar stationary phase and a non-polar mobile phase, and utilizes capillary
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Data and observation collected from column and TLC (silica stationary plate) on a mixture of ortho and para nitroaniline .The eluent used was a mixture of hexane and ethyl acetate, (13 ml) and (7 ml), respectively; the mobile phase used for the TLC was acetone.
Fraction collected from elution of the dry column chromatography Mobile Phase used in Column Color and Number of Spots Observed Rf Value
Test Tube 4-12 Mixture: hexane (13 ml) and ethyl acetate (7 ml) 9 clear-mustard yellow spots 0.27
Test Tube 1-3 Mixture: hexane (13 ml) and ethyl acetate (7 ml) 3 mustard yellow-clear 0.49
Discussion
Separation of the mixture of ortho and para nitroaniline indicates that the hypothesis is possible using the two techniques described. This can be understood by the different Rf values of the two components (Table 1). 2 Ortho was found to have an Rf value of approximately 0.60 and para was found to have a value of 0.45; this was found when ethyl acetate was used as the mobile phase.
The experiment used three mobile phases and the results show that ethyl acetate is the most polar followed by acetone and finally hexane (as virtually no separation occurred when hexane was the mobile phase). This is indicated by the Rf values that are given in Table 1. Given the results from Table 2 and Table 1 it can be said that the first three spots were ortho (Rf 0.49 and 0.60) and the last nine spots were para (Rf 0.27 and
Data and observation collected from column and TLC (silica stationary plate) on a mixture of ortho and para nitroaniline .The eluent used was a mixture of hexane and ethyl acetate, (13 ml) and (7 ml), respectively; the mobile phase used for the TLC was acetone.
Fraction collected from elution of the dry column chromatography Mobile Phase used in Column Color and Number of Spots Observed Rf Value
Test Tube 4-12 Mixture: hexane (13 ml) and ethyl acetate (7 ml) 9 clear-mustard yellow spots 0.27
Test Tube 1-3 Mixture: hexane (13 ml) and ethyl acetate (7 ml) 3 mustard yellow-clear 0.49
Discussion
Separation of the mixture of ortho and para nitroaniline indicates that the hypothesis is possible using the two techniques described. This can be understood by the different Rf values of the two components (Table 1). 2 Ortho was found to have an Rf value of approximately 0.60 and para was found to have a value of 0.45; this was found when ethyl acetate was used as the mobile phase.
The experiment used three mobile phases and the results show that ethyl acetate is the most polar followed by acetone and finally hexane (as virtually no separation occurred when hexane was the mobile phase). This is indicated by the Rf values that are given in Table 1. Given the results from Table 2 and Table 1 it can be said that the first three spots were ortho (Rf 0.49 and 0.60) and the last nine spots were para (Rf 0.27 and