Thin Layer Chromatography
Thin Layer Chromatography
Submitted in partial fulfillment of the requirements for:
CHE 324
Organic Chemistry Laboratory
Dr. Robert Duncan
Fall Semester 2012
Caitlin Inman, Team Leader
October 9, 2012
Tyler Byrd, Data Collection
Shared Role, Technique Expert
Introduction:
“Chromatography is used to separate components of a mixture. For example, imagine a mixture of wood pieces, pebbles, and large rocks to be separated and the chromatography setup as a stream. Flowing water is then the moving phase, and the bottom of the stream is the stationary phase. If our mixture is thrown into the stream, the wood pieces will move freely with the flowing water. The wood has, therefore, a high affinity (or attraction) for the moving phase. The large rocks will stay at the bottom and, thus, have a high affinity for the stationary phase. Finally, the pebbles will roll slowly at the bottom and have an intermediate affinity for the moving phase and for the stationary phase” (Brozek). Thin Layer Chromatography (TLC) is a solid-liquid technique in which the two different phases are a solid stationary phase and a liquid mobile phase. TLC can be used to detect a given compound in a mixture, follow the course of the reaction, follow the purification of a compound, or evaluate the purity of the compound.
Objectives:
Certain objectives needed to be met in order for the Thin Layer Chromatography (TLC) experiment to be understood and completed. The identification of an unknown, and the techniques and principles of TLC had to be mastered to identify an unknown substance based on comparisons of lab standards and Rf factors. The next objective was to measure the distance a solvent travels and how to calculate the Rf factor of a compound.
Table of Physical Constants: Substance | Picture | Molecular Weight(g/mol) | Boiling Point °C | Melting Point°C | Density(g/cm3) | Hazards | p-nitrotoluene | | 137.14 | 238 | 51 | 1.29 | * Toxic * Dangerous for
Submitted in partial fulfillment of the requirements for:
CHE 324
Organic Chemistry Laboratory
Dr. Robert Duncan
Fall Semester 2012
Caitlin Inman, Team Leader
October 9, 2012
Tyler Byrd, Data Collection
Shared Role, Technique Expert
Introduction:
“Chromatography is used to separate components of a mixture. For example, imagine a mixture of wood pieces, pebbles, and large rocks to be separated and the chromatography setup as a stream. Flowing water is then the moving phase, and the bottom of the stream is the stationary phase. If our mixture is thrown into the stream, the wood pieces will move freely with the flowing water. The wood has, therefore, a high affinity (or attraction) for the moving phase. The large rocks will stay at the bottom and, thus, have a high affinity for the stationary phase. Finally, the pebbles will roll slowly at the bottom and have an intermediate affinity for the moving phase and for the stationary phase” (Brozek). Thin Layer Chromatography (TLC) is a solid-liquid technique in which the two different phases are a solid stationary phase and a liquid mobile phase. TLC can be used to detect a given compound in a mixture, follow the course of the reaction, follow the purification of a compound, or evaluate the purity of the compound.
Objectives:
Certain objectives needed to be met in order for the Thin Layer Chromatography (TLC) experiment to be understood and completed. The identification of an unknown, and the techniques and principles of TLC had to be mastered to identify an unknown substance based on comparisons of lab standards and Rf factors. The next objective was to measure the distance a solvent travels and how to calculate the Rf factor of a compound.
Table of Physical Constants: Substance | Picture | Molecular Weight(g/mol) | Boiling Point °C | Melting Point°C | Density(g/cm3) | Hazards | p-nitrotoluene | | 137.14 | 238 | 51 | 1.29 | * Toxic * Dangerous for
Cited: 1. Brozek, Celestyn M., Chromatography, Journal of Chemical Education 1999 76(1), 83, ACS Publications http://pubs.acs.org/doi/pdf/10.1021/ed076p83. 2. Malins, Donald C. and Wekell, John C., TLC-Versatile Tool. Journal of Chemical Education 1963, 40 (10), 531, ACS Publications http://pubs.acs.org/doi/pdf/10.1021/ed040p531.