Tlc Chromothography
IDENTIFICATION OF UNKNOWN SOLUTIONS USING TLC CHROMATOGRAPHY
Purpose: To become familiar with the principles and terminology of TLC chromatography to identify an unknown molecule based on comparisons with known laboratory standards and Rf factors.
Background
Thin Layer Chromatography:
Chromatography is a sophisticated method of separating and identifying mixtures of two or more compounds. The separation is accomplished by the distribution of the mixture between two phases: one that is stationary and one that is moving or mobile. Chromatography works on the principle that different compounds will have different solubilities and adsorption to the two phases, which will allow for their separation.
Thin Layer Chromatography (TLC) is a solid-liquid technique in which the two phases are a solid, stationary phase and a liquid, mobile phase. The solid phase you will be using in today’s lab is a plastic plate covered with an adsorbent, in this case, silica gel. Aluminum is another common solid phase used. Because silica is a polar molecule, the components of the solution we will use in lab today will be separated based on their relative polarities. The more polar a molecule, the higher affinity it will have for the more polar silica plate and will therefore spend less time in the mobile phase. As a result, it will move up the plate more slowly. Conversely, a less polar molecule will spend more time in the mobile phase and will therefore move up the plate more quickly. The speed at which the molecules will move up the plate thus depends on the relative difference in polarity between the stationary and mobile phases, and will vary depending on the nature of the stationary and mobile phases used for separation.
The following are some common uses of Thin-Layer Chromatography: 1. To determine the number of components in a mixture. 2. To determine the identity of two substances. 3. To monitor the progress of a reaction
The difference each molecule
Purpose: To become familiar with the principles and terminology of TLC chromatography to identify an unknown molecule based on comparisons with known laboratory standards and Rf factors.
Background
Thin Layer Chromatography:
Chromatography is a sophisticated method of separating and identifying mixtures of two or more compounds. The separation is accomplished by the distribution of the mixture between two phases: one that is stationary and one that is moving or mobile. Chromatography works on the principle that different compounds will have different solubilities and adsorption to the two phases, which will allow for their separation.
Thin Layer Chromatography (TLC) is a solid-liquid technique in which the two phases are a solid, stationary phase and a liquid, mobile phase. The solid phase you will be using in today’s lab is a plastic plate covered with an adsorbent, in this case, silica gel. Aluminum is another common solid phase used. Because silica is a polar molecule, the components of the solution we will use in lab today will be separated based on their relative polarities. The more polar a molecule, the higher affinity it will have for the more polar silica plate and will therefore spend less time in the mobile phase. As a result, it will move up the plate more slowly. Conversely, a less polar molecule will spend more time in the mobile phase and will therefore move up the plate more quickly. The speed at which the molecules will move up the plate thus depends on the relative difference in polarity between the stationary and mobile phases, and will vary depending on the nature of the stationary and mobile phases used for separation.
The following are some common uses of Thin-Layer Chromatography: 1. To determine the number of components in a mixture. 2. To determine the identity of two substances. 3. To monitor the progress of a reaction
The difference each molecule