Analysis of APC tablets. An inexpensive and practical thin-layer chromatography experiment

Abstract

By using a commercial item, students are faced with a "live" problem connected with everyday living.

Dietary fat and health: An experiment on the determination of iodine number of fats and oils by coulometric titration

“…An approximately 0.1 N solution of IC1 is prepared by dissolving 8-8.5 g of IC1 in 1L of glacial acetic acid. Exactly 10.00 mL of this IC1 solution and 20 cell. From a buret an exactly measured, slight excess of the standardized thiosulfate solution is added to destroy the I2 produced from the reaction of the ICI with the Kl.…”

Incorporation of consumer products in the teaching of analytical chemistry

“…Separation of the active ingredients (aspirin, caffeine, and acetaminophen) in analgesic tablets, such as Excedrin, is performed by thin-layer (5) and also by high-performance liquid chromatography (6). In the case of thin-layer chromatography, the students are asked to identify the components by their Rj values as well as by their ultraviolet spectra, obtained after removal from the plate and dissolution in methanol.…”

The aspirin project. Laboratory experiments for introductory chemistry

“…Tablets which contain phenacetin and/or caffeine in addition to acetylsalicylic acid and starch provide a more challenging separation problem (2). An extraction with excess cold ether separates the very soluble acetylsalicylic acid and moderately soluble phenacetin from the insoluble caffeine and starch.…”

“…Both the starch binder, common in all commercial aspirin tablets, and caffeine, which is found in certain acetylsalicylic acid-containing analgesic preparations, have been isolated by students in sufficient purity to allow for characterization by study of physical and spectroscopic properties. A few students have successfully separated and identified components using a recently reported thin-layer chromatographic procedure (2). Finally, a small number of students have extended their studies to "buffered" and "extrastrength" commercial samples.…”