A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C.

VITAMIN C; ORGANIC chemistry; OPTICAL spectroscopy; PHENANTHROLINE; PUBLIC health

Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid, easily implemented experiment was developed to measure vitamin C levels in solutions using visible spectroscopy. When vitamin C is added to a mixed reagent containing Fe3+ and 1,10-phenanthroline, the vitamin C reduces the Fe3+ to Fe2+ which subsequently combines with the 1,10-phenanthroline to form a reddish-orange colored complex that is measured by visible spectroscopy at 510 nm. The experiment includes measurement of the stability of aqueous vitamin C solutions when exposed to long-term storage and to heat. Students in GOB laboratory classes were able to produce results with good precision. The experiment was also extended to include the measurement of vitamin C in nutrition supplements. [ABSTRACT FROM AUTHOR]

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