Quantitative Determination of Usnic Acid in Usnea Strigosa through High Performance Liquid Chromatography

Andrew Maly and Myles Stackhouse

Usnic acid is a chemical produced in the metabolic process of some species of lichenized fungi or lichens including Usnea strigosa. The ability to reliably calculate the concentration of usnic acid and purify the acid found in these lichens will be incredibly useful in further research. To this goal, HPLC, High Performance Liquid Chromatography, was utilized to calculate the absorbance values of an usnic acid standard and its dilutions. However, the preliminary HPLC results showed too many peaks, which indicated impurities in the usnic acid sample. A recrystallization technique will be implemented to remove these impurities. Further testing will be done to determine the purity of the recrystallized acid sample using a polarimeter. After confirming purity, the recystalized usnic acid sample will be used to create a standard, and the standard along with its dilutions will be run in the HPLC. These results from the HPLC will then be used to create a calibration curve. Using this calibration curve and accounting for dilution factors, the presence and the concentration of usnic acid in the collected Usnea strigosa samples will be determined. [Poster pending additional data.]

• Andrew Maly is a senior chemistry major with an emphasis in forensic science. He is originally from Troisdorf, Germany but has been living in the United States since 2007. After graduation, he hopes to either enter the workforce as a forensic lab assistant or continue education in Europe.

• Myles Stackhouse is a sophomore chemical engineering major from Abbeville, SC. His dream is to become a flavorist. He splits his time between classwork, his work as a Jehovah's Witness, and his passions for cooking and music.