Organic humidity may be controlled by dissolving a fatty acid or nitrile in an organic solvent. The vapor pressure of a solvent will be reduced whenever it is dissolved in a compound with a higher solubility than whenever it is dissolved in a compound with a lower solubility. Our project has focused on controlling organic humidity, and monitoring it with a simple apparatus that would be accessible to anyone interested in replicating our work. A closed system consisting of a vacuum pump, IR gas cell, and Erlenmeyer flask is assembled. Then an organic reservoir is allowed to equilibrate through our closed system so that the atmosphere in the IR gas cell is identical to that of the atmosphere directly above our reservoir. The organic analytes of interest have been found to absorb strongly at around 1465 cm-1 and 1386 cm-1 for CH2 and CH3 peaks respectively. The absorbance is directly proportional to the concentration of the organic analytes in the atmosphere. Additionally, the solubility of different saturated reservoirs has been determined with UV-Visible Spectroscopy and standard dilutions, where all of our compounds were found to absorb strongly at 204 nm. Developing a method to control organic humidity will be important for future work where we try to carry out chemical reactions utilizing atmospheric solvent and need a way of regulating the vapor pressure of the solvent. Compounds tested thus far include: lauric acid, decanoic acid, palmitic acid, stearonitrile, hexadecylamine, stearic acid, and myristic acid.

The group would like to thank their faculty sponsor Dr. Paul Bracher for their support of this project.