Column Chromatography Lab Report

In the following reaction, benzil was rearranged to from benzilic acid by reacting it with potassium hydroxide in ethanol. 0.100 benzil was utilized and the theoretical yield of benzilic acid was 0.109 grams (see Eq 5). The final yield and weight of benzilic acid was 0.60 grams. The final yield and theoretical yield were used to calculate the percent yield, 55% (similar to Eq 3). The melting point of benzilic acid was 148.3C and the literature value for

Sanger settled instead on partition chromatography that had been developed in the1940s by Richard Synge and Archer Martin. This technique is that packed a tube tipped with ground up silica gel, then wetting the gel with water and pipetting in an amino acid solution at the top. Chloroform then inserted to wash the amino acid solution through and added a methyl red dye. The dye formed red bands against to an orange background which helped show up the separated amino acids. First tine Sanger tested methane sulfonyl chloride proved this reagent disappointing.

The purpose of refluxing the reaction was to break the bond in the p-acetaminophen and acetic anhydride at the same time the condenser prevent some molecule to escape though evaporation by capturing it and return it into the reaction vessel. The heat was necessary to break bond in P-acetaminophen and in acetic anhydride by increasing the rate of reaction and bringing molecules closer to the activation energy. Product isolation was performed by cooling the solution, and filtered it to isolate the crystals of the products by using Hirsch funnel. This crude product was then purified through recrystallization technique and by using Craig tube. The final process was to identify the product by using dig melt machine to find out the melting point

Paper Chromatography and Spectrophotometry Used to Identify Amino Acids and Concentration of Protein in Solution Introduction: Paper chromatography was used to characterize known amino acids in solution with an accordant Rf value. These Rf values were then used to identify a solution with unknown amino acids and observed Rf values. An Rf value is calculated using the following formula:Distance Traveled by solute (cm)Distance Traveled by solvent (cm), where the distance traveled by solute is measured from the origin line to the center of the solute spot (Lombard, p19). A polar matrix, composed of cellulose, was utilized in tandem with a nonpolar solvent (Ammonia:Ethanol:dH2O) during paper chromatography (Freeman, et al. p113). This diversity

The ethyl (3-oxo-2,3-dihydro-4H-1,4-benzothiazin-4-yl)acetate 4C (0.05 mol, 14.37g) was warmed in a mixture of ethanol and DMF (1:2) to get a clear solution and was cooled to room temperature. A solution of KOH (0.08 mol, 4.81g) in water (10 ml) was added to this solution and the mixture was stirred for 24h at room temperature to ensure the completion of the reaction. The completion of the reaction was monitored by TLC (CHCl3:MeOH, 9:1). The reaction mixture was evaporated to dryness and the residue dissolved again by adding ice cold water. The insoluble impurities were separated by filtration and the filtrate was acidified with 4N HCl to get a solid product (3-oxo-2,3-dihydro-4H-1,4-benzothiazin-4-yl)acetic acid (4D), collected by filtration.

Thin-layer chromatography (TLC) is a chromatography technique used to separate the components of a mixture. It can be used to monitor the progress of a reaction, determine the purity of a substance, and identify compounds present in a given mixture. TLC is performed on a sheet of glass, plastic, or aluminum foil, which is coated with a thin layer of adsorbent material, usually silica gel, aluminum oxide, or cellulose. This layer of adsorbent is known as the stationary phase. After the sample has been applied on the plate, a solvent or solvent mixture is drawn up the plate via capillary action (known as the mobile phase).

Once the final solid product was obtained in both reactions the melting point procedure was used to determine the level of remaining impurity of the final product, comparing the experimental and expected values found in literature. In conjunction with the melting point procedure, infrared spectroscopy was used to reveal the different functional groups of the products. In other words, the IR machine indicates whether our final product matches up with the desired one, matching carbonyl and alcohol absorption peaks (or the lack thereof) to their theoretical presence (either benzil or benzillic acid).

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Ethanol (3.5 mL, ...M) was added to Benzoin (...g) followed by an addition of sodium borohydride solution to the suspension of Benzoin in ethanol. The mixture was then heated with swirling. After the benzoin in the mixture was dissolved, it was heated for further 1-2 minutes with occasional swirling. The hot solution was then diluted with water. The suspension was then chilled and the product was collected by vacuum filtration. The product was then further recrystallized from the minimum amount of hot ethanol to give colourless glistening plates. (....g, % yield), m.p.

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.

It can be concluded that column chromatography is an effective way of separating components of a mixture. The crude pigment was sent through the column however three distinctly separate layers were collected (yellow, green-blue and blue). Each coloured layer represented a different pigment. It was made clear by the column chromatography that the beta-carotene (yellow) is the least polar pigment, chlorophyll b (green) is the most polar and chlorophyll a (blue-green) is intermediately polar based on the order the pigments were eluted. In the column, the least polar pigment eluted first as it adhered best to the 8:2 pet ether: acetone mobile phase. The last pigment that passed through was chlorophyll b as it was the most polar and adhered greatly to the silica. The effectiveness of column chromatography was confirmed using thin layer chromatography. On the silica plate, a spot was added for each separated pigment and the crude pigment. A highly effective separation using column chromatography would show corresponding distances travelled for the three separate colours and the three spots the crude separated into on the TLC plate. This confirmed that the column separated the pigments into the correct three layers. On the TLC

The objective of this experiment was to calculate the lower concentration limit of detection and detection threshold through instrumental analysis and human psychophysics, respectively. These values were then statistically compared to determine the superior method and inherent advantages/disadvantages were reviewed.1 Gas chromatography (GC) is a critical tool in a wide array of applications relating to food analysis, for the separation of various compounds (especially volatiles) within a mixture is typically essential in the characterization of inherent aroma compounds and undesirable defects of a given food product. Therefore, accurate quantification/qualification using GC/human psychophysics is a crucial aspect of the research and development

The goal of this lab was to synthesize benzocaine by utilizing Fischer esterification, reflux, and melting point determination techniques. These techniques were successfully performed and the synthesis was successfully performed. Although, the synthesis was not very efficient due to the low percent yield of the product (28%) and the melting point of the product not correlating to that of benzocaine.

The 4-nitrobenzoic acid product had a percent yield of 48.89%, showing a very high yield out of 50%. The melting point range was from 236-238°C, whereas the literature value is 237-240°C. The melting point of the product was very close to the literature value and also had a narrow range, indicating a pure product and therefore deeming recrystallization unnecessary. However, if the acid need to be purified, methanol would be used as the recrystallizing solvent.

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