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Isolation of the Components of BC Powder

Introduction

Aspirin, Caffeine and Salicylamide were extracted from an over-the-counter pain reliever (BC Powder). These components were separated by manipulating their solubilities by adjusting the acidity and basicity of the solution. By doing this, the three components were forced into conjugate acid (or base) forms, causing selective solubility in either an aqueous or organic solvent. These layers were then separated by use of a separation funnel. Once separated, the components extracted were characterized by measuring the melting point and performing a TLC analysis. Also, the recovered aspirin from the first part of the experiment was recrystallized and compared to that of the …show more content…
The aspirin was first ionized by the addition of a basic compound, sodium bicarbonate, into solution. This caused the aspirin to be locked into the aqueous layer and readily separated by means of a separatory funnel. Once separated, the aspirin was returned to its initial form by the addition of hydrochloric acid. To remove the sodium chloride salts and water, the solution was vacuum filtered. This process yielded a 52% recovery of the aspirin by mass. It is assumed that aspirin molecules remaining in the organic solvent layer was responsible for the missing mass. During the melting point analysis, the aspirin melted in the temperature range of 93 - 98 ºC. This shows a 30% error from the literature value of 135 ºC. The TLC analysis also supports that this basic extract was aspirin, as the Rf values of the basic extract and the standard aspirin were identical (0.38). The next component to be isolated was the caffeine. The organic layer set aside after the removal of aspirin was treated with hydrochloric acid, which put the ionized caffeine into the aqueous solvent and the third component, salicylamide into the organic solvent. Setting the organic layer aside, caffeine was returned to its original form by the addition of sodium hydroxide, a base, to the solution. To remove the resultant ionic compound sodium chloride and the water, the caffeine