Thin Layer Chromotography Discussion

The stationary phase will absorb or slow down different components of the tested solution to different degrees creating layers as the components of the solution are separated. Chromatography was invented by the Russian botanist, Mikhail Tsvet. Chemists use this process to identify unknown substances by separating them into the different molecules that make them up.

Thin Layer Chromatography (TLC) works in relation to the polarity of chemicals. A plate is first covered with aluminum foil or silica etc. and has solutions of varying polarities placed upon the aluminum foil or silica. When placed in a in a puddle of solvent that moves up the plate, the different inks i.e. the solution will move up the place based on their Rf values. Adherence increases with increasing polarity, so the less polar compounds will be carried farther by the solvent. Eventually the dyes will separate into their compontnets, which can be visibly seen. This is then used to determine who the ink of the unsigned note belonged to along with the pen that it belonged

Lycopene and β-carotene are separated using thin layer chromatography (TLC). A mixture of tomato paste containing dissolved lycopene and β-carotene is first spotted on a TLC plate. The technique uses a stationary phase layer, on which the substances stick, and a mobile phase, which migrates upwards the plate and carries the components of the mixture with itself (Chemguide). Depending on their respective polarity, lycopene and β-carotene stick more or less to the stationary phase and so they migrate up the TLC plate at different rates (Chemguide). Thus, as the chromatography is completed, the two components will appear as distinct dots at different heights on the plate. Lycopene has a bright orange color, whereas β-carotene is light yellow.

On a thin chromatography plate, five spots were placed ( as shown in table 2) and the plate was developed using chloroform/methanol. This was later visualized with dragendorff’s reagent under the UV light. All separated components were observed, identified and recorded.

In the beginning of this experiment, our TA added water, salt, and 75/25 hexane/acetone to spinach leaves to a blender and blended the mixture to assume equal amounts for each group and to avoid erros if each student had to do the blending. The addition of the water to the mixture allowed the it to separate into a distinct organic layer after being run in a centrifuge, which was available to be collected at the top of the centrifuge. Salt reduces solubility, which will force the organic parts of the mixture (the desired pigments for example) to separate into the organic layer at the top. Lastly, 75/25 hexane/acetone is added because this is a moderately polar solvent and will useful for both the non-polar and polar pigments present within the spinach leaves. A mixed solution of hexanes and acetone must be used because acetone is very polar, while hexane in very non-polar, and the spinach leaves contain both non-polar and polar pigments in them that are important in the extraction and for further analysis. The mixture was placed in the centrifuge so the solids in the mixture (mostly cellulose) could be separated from the liquids into separate distinct layers for further extraction and testing. In the tube, the organic substances separated into the top layer, whereas the water layer remains at the bottom of the tube below the solid layer made up of mainly cellulose.

The main goal in doing the column and thin layer chromatography was to separate spinach extract into its components based on polarity and then to analyze the components. The separation of the spinach extract was done using the column chromatography with the wet/slurry packing method. Alumina was inserted into the column to act as the stationary phase. After the components were separated and the solvents boiled out, the thin layer chromatography was performed to analyze the components of the spinach extract. This was done using a TLC plate and spotting each of the

[3] M.G. Dauyvis et al., J Agric. Food Chem., 2002, 50, 1548-52. Role of Ri

The isolation and purification of phosphatidylcholine from egg yolk is successfully achieved through aluminum oxide chromatography. The chromatography-purified fractions of PC is concentrated by doing thin layer chromatography. The TLC plate from first two fractions showed indication of PC, which describes the separation is very faster than the typical experiment. Usually fractions 5-9 contains the highly concentrated PC ( Clingman ).The net weight of the PC obtained after all the purification is 1.14grams.The TLC analysis between crude PC and purified PC is compare with standard lyso PC.The purified PC and crude PC has same Rf value but crude PC has additional spots that are not present in purified run. Since the purified PC has one prominent

Exploring Thin Layer Chromatography Thin layer chromatography (TLC) is used to to identify organic compounds with common over-the-counter medicine; and the relative strength of the intermolecular forces and how they affect the compound’s polarity within the medications tested. TLC is the physical separation of a mixture into its individual components by distributing the components between a stationary phase, or silica gel; and a mobile phase, or movement of sample up the TLC plate to the solvent front. The mobile phase is considered to be non-polar, the non-polar components of the sample will travel farther up the TLC plate than the polar components that will stay near the stationary phase.

Chromatography Investigation Chromatography is a highly regarded technique used to separate the components of a mixture. It is based on the principle that each component possesses a unique affinity for a stationary phase and a mobile phase. The components that are more inclined to enter the mobile phase will migrate further on the chromatogram and distinguish themselves from the other components. The type of solvent used in chromatography is known to directly affect the separation of the mixture. In this experiment, thin-layer and column chromatography will be utilized to separate the numerous chlorophyll and carotenoid pigments of a spinach extract.

Method: Some of the sample (0.1986 g, 1.188 mmol) was dissolved in acetone-d6 (500 µL) and a 1H NMR spectrum of this sample was collected. The sample was then finely grounded and its IR spectrum was subsequently collected. After this, the melting point of the sample was measured. Then the sample was dissolved in dichloromethane, and this sample solution was analysed by thin layer chromatography (TLC) along with 4-nitroaniline, 2-nitrobenzoic acid and 4-nitrophenol solutions where the eluent was dichloromethane (10 mL). This TLC analysis was repeated with another eluent prepared from methanol (1 mL) and dichloromethane (9 mL).

1.1.1.3 Separations Based on Polarity The arrangement of the atoms along with their in-between bonds, determine the structure and physicochemical properties of an organic molecule and with the presence of a particular atomic arrangement in a molecule, known as "functional group", the properties, chemical reactions and the polarity of that molecule can be predicted, making the classification of the organic molecules based on their principle functional group possible. Based on polarity for performance of a separation, by the nature and location of the functional group in molecules, their chromatographic retention can be determined and by ordering the molecules into a spectrum according to their polarity in chromatography, a range of highly polar to highly non-polar molecules can be shown (Figure 1.3). In chromatographic separations based on the polarity,

After this, assuming no complications, the ratio of these compounds is 2.0 to up to 4 or more at 40 weeks. Infants who have a ratio of 2.0 or more rarely develop RDS (Wardelab.com, 2017). It denotes alveolar stability and lung maturity. After extraction, the L:S ratio can be measured using Thin Layer Chromatography (TLC). TLC is a useful technique for separation and identification of a compound(s) when in a mixture. Compounds are separated by their differences in their solubility. There are two phases to separate the mixtures, mobile phase and stationary phase. In this experiment the mobile phase is the solvent which is chloroform:methanol:water in ratio 13:5:0.8 v/v. The stationary phase is the TLC plate, coated with silica gel. When the samples are spotted at the bottom of the TLC plate. It is then placed in a container containing the solvent (mobile phase). The solvent will then move up the TLC plate by capillary action, moving the mixtures at different rates, thereby separating them. When the solvent nearly reaches the top, the TLC plate is removed and the solvent front is

Chromatography is a process commonly used to separate substances in accordance to their differential distribution between what is referred to as a stationary phase and a moving or ‘mobile phase’. There are a variety of different types of chromatography some include; paper chromatography, gas chromatography and high performance liquid chromatography.

Chromatography is a separation technique in which the mixture to be separated is dissolved in a solvent and the resulting solution, often called the mobile phase, is then passed through or over another material, the stationary phase. The separation of the original mixture depends on how strongly each component is attracted to the stationary phase. Substances that are attracted strongly to the stationary phase will be retarded and not move alone with the mobile phase. Weakly attracted substances will move more rapidly with the mobile phase.