Isolation of Caffeine from Tea

Organic Chemistry 241L

Wed. 1 pm/ sec. -003 Stuart/Haim Richman

Dr. Vaduvescu 09/29/2013

Isolation of Caffeine from Tea

Abstract

This experiment mainly focuses on the extraction of almost pure caffeine from two Lipton tea bags and determining its percent yield. A 0.29% yield of pure caffeine was obtained from 5.3551g of tea leaves (2 tea bags). Caffeine is soluble in both water and organic solvents and solid-liquid extraction and liquid-liquid extraction were used in the experimentation process. Caffeine was extracted using hot water, however, due to its medium polarity; it was further separated from water soluble compounds using a polar non-aprotic solvent, dichloromethane (CH2Cl2). There was a 47.2mg or 14.55% yield difference between what the manufacturer claimed per tea bag and what the experiment came up with. The experimental results could be perceived as a bit low due to experimental errors or manufacturers’ error.

Introduction

Tea has been consumed as a beverage for almost 2,000 years starting in China. It is the most widely consumed beverage after water (Alan M & Iris M, 2004).Their active participation in trade resulted in its introduction to Europe. The active component in tea is caffeine (C8H10N4O2). Caffeine is a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines.

Caffeine belongs to an extensive class of compounds known as the alkaloids. Alkaloids are a diverse group of compounds that are found primarily in plants and contain basic nitrogen atom/s.

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The basic nature of these compounds makes them exists mostly as salts. Many alkaloids have profound effects on the nervous system and acts as a mild stimulant examples are other well-known alkaloids...