Tlc Lab
PAPER AND THIN-LAYER CHROMATOGRAPHY Lab 47
Michael Stravino, CHM 2211L, June 3, 2012
Abstract
Thin-Layer Chromatography and Paper Chromatography can be used to identify identical compounds, unknown compounds, the number of components in a mixture, as well as other important uses not explored in this laboratory. This experiment explores these techniques to identify an unknown amino acid by TLC and analyze food colors using paper chromatography. By using 2.0 mL of dimethoxyethane and 18 mL of absolute ethanol as the developing solution, and then spotting each sample of amino acids and an unknown on the silica gel chromatography plate, we began the process of TLC plating. The ninhydrin solution was sprayed on the chromatography plate and allowed to dry. After allowing the solution to dry, we outlined the spots and calculated the Rf values to determine the identity of unknown #936 was phenylalanine. In regards to the Paper Chromatography experiment, the same steps were taken, but instead 5 mL of distilled water, 5 mL of 1-propanol, and 5 mL of 1-butanol were used in the developing chamber. The ingredients of each food coloring were analyzed using the Rf values of all the spots.
I. Introduction
Purpose: The purpose of this experiment was to become familiar with the techniques of chromatography. Chromatography is used to separate the components of a mixture. The techniques in this laboratory were used to identify amino acids by use of Thin-Layer Chromatography, and paper chromatography was used to analyze food coloring. Thin-Layer Chromatography has a close relationship with column chromatography; however, the solvent ascends in Thin-Layer, rather than descending, which are seen by column chromatography. The Thin-Layer Chromatography is used to identify two compounds that are identical, and can also determine the number of components in a mixture1. The Rf value is helpful to identify an unknown compound by duplicating the same Rf value.
Michael Stravino, CHM 2211L, June 3, 2012
Abstract
Thin-Layer Chromatography and Paper Chromatography can be used to identify identical compounds, unknown compounds, the number of components in a mixture, as well as other important uses not explored in this laboratory. This experiment explores these techniques to identify an unknown amino acid by TLC and analyze food colors using paper chromatography. By using 2.0 mL of dimethoxyethane and 18 mL of absolute ethanol as the developing solution, and then spotting each sample of amino acids and an unknown on the silica gel chromatography plate, we began the process of TLC plating. The ninhydrin solution was sprayed on the chromatography plate and allowed to dry. After allowing the solution to dry, we outlined the spots and calculated the Rf values to determine the identity of unknown #936 was phenylalanine. In regards to the Paper Chromatography experiment, the same steps were taken, but instead 5 mL of distilled water, 5 mL of 1-propanol, and 5 mL of 1-butanol were used in the developing chamber. The ingredients of each food coloring were analyzed using the Rf values of all the spots.
I. Introduction
Purpose: The purpose of this experiment was to become familiar with the techniques of chromatography. Chromatography is used to separate the components of a mixture. The techniques in this laboratory were used to identify amino acids by use of Thin-Layer Chromatography, and paper chromatography was used to analyze food coloring. Thin-Layer Chromatography has a close relationship with column chromatography; however, the solvent ascends in Thin-Layer, rather than descending, which are seen by column chromatography. The Thin-Layer Chromatography is used to identify two compounds that are identical, and can also determine the number of components in a mixture1. The Rf value is helpful to identify an unknown compound by duplicating the same Rf value.
Citations: D.L. Pavia, G.M. Lampman, G.S. Kriz, and R.G. Engel “Introduction to Organic Laboratory Techniques: A Small Scale Approach, 3rd Ed.”, (2011) Brooks/Cole, pp. 800-809