Natural Product Extraction: Isolation of Caffeine from Tea, Thin Layer Chromatography

Natural Product Extraction: Isolation of Caffeine from Tea, Thin Layer Chromatography

And

Sublimation of Caffeine from Tea

I. Results

A) Table 1. Table describing the TLC results of the Standardized Caffeine, Crude Caffeine(from extraction) and Purified Caffeine ( from sublimation).

Solvent System Sample Spot Label Rf

Std Caffeine 1/1.3 = 0.76%

Beam Crude Caffeine 0.79%

Purified Caffeine 0.59%

Std Caffeine 2/ 2.6= 0.76%

EtOACMeOH H2O Crude Caffeine 0.76%

Purified Caffeine 0.69%

B) Table 3. Pertinent Data for Sublimation and Extraction

Data Before Sublimation After Sublimation

Mass of Caffeine 1.19 g (Extraction sample) 0.09 g

Mass of Setup 92.96g 93.05 g

C) Figure 1. Thin Layer Chromatography Results

II. Discussion

Extraction, the first portion of the set of experiments, is a technique that is capable of separating a specific substance by differentiating the layers of components. The experiment had the constant use of methylene chloride to act as a medium for separating the caffeine from the teabags. Methylene chloride is non-polar It was implemented five times to assure that the purity of the substance would be as pure as possible. The sodium sulfate was used to dry the substance after the five washes. This process was carried out to have a clear,visual representation of the two different layers created: the caffeine and the miscellaneous impurities.

Thin Layer Chromatography, the second portion of the experiment, was an analytical process that allowed for the viewing of the caffeine samples from the extraction in the previous experiment. The only notable portion for this experiment was the BEAM (benzene/ether/acetic acid/ methylene) and EAM templates for the TLC plates. The plates were dabbed with samples of a standardized caffeine and the crude sample obtained from the experiment for comparison of samples. For this case, the spots were fairly similar in elevation and shape when viewed under UV Light.

Sublimation, the last part of the experiment, is a technique that allows for further purification of a solid substance without the substance having to undergo a liquidated phase. The sublimator, the apparatus used for this experiment, consisted of an evaporating dish, a funnel, filter paper and