Compositional Analysis of Mixtures of Oleate Esters of Short Chain Alcohols (C1-C4) by Quantitative Proton Nuclear Magnetic Resonance Spectroscopy (qPNMR)

Ronald P. D’Amelia^1, , Brandon Khanyan¹ and Joseph Mancuso¹

¹Chemistry Department, Hofstra University, Hempstead, NY

Cite this paper

Ronald P. D’Amelia, Brandon Khanyan and Joseph Mancuso. Compositional Analysis of Mixtures of Oleate Esters of Short Chain Alcohols (C1-C4) by Quantitative Proton Nuclear Magnetic Resonance Spectroscopy (qPNMR). World Journal of Chemical Education. 2022; 10(1):1-7. doi: 10.12691/WJCE-10-1-1

Abstract

Quantitative nuclear magnetic resonance spectroscopy (qNMR) is a technique used to determine the concentration of one or more analyte within a mixture. Although NMR spectroscopy is typically used to qualitatively determine molecular structure, the quantitative application of NMR extends to concentration determinations and purity assessments. Described herein is an experiment designed to increase awareness of both the qualitative and quantitative applications of NMR spectroscopy that could be integrated into undergraduate analytical and instrumental chemistry laboratory course curriculums. The experiment entails the quantitative analysis of binary long-chain monounsaturated fatty acid mixtures ranging from 0% to 100% in 20% intervals of methyl oleate (MeOl), ethyl oleate (EtOl), propyl oleate (PrOl) and butyl oleate (BuOl) using proton NMR. The goal of the experiment is to determine the structure and weight percent composition of both analytes in each of the mixtures. The results show a strong, linear correlation between the gravimetric compositions and the weight percent compositions found using proton NMR. The experiment supports qNMR as a tool for determining weight percent compositions of mixtures and can be incorporated at the undergraduate chemistry laboratory level.

Keywords

quantitative analysis, Nuclear Magnetic Resonance, undergraduate laboratory experiment, hands-on learning, oleate esters, oleate ester mixtures

Copyright

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References

[1]	Woodworth J.K., Terrance J.C., and Hoffmann M.M, “Using Nuclear Magnetic Resonance Spectroscopy for Measuring Ternary Phase Diagrams”, J. Chem. Educ., 83(7), 1065-1066, July 2006.
[2]	Isaac-Lam M.F., “Analysis of Bromination of Ethylbenzene using a 45 MHz NMR Spectrometer: An Undergraduate Organic Chemistry Laboratory Experiment”, J. Chem. Educ., 91, 1264-1266, July 2014.
[3]	McGregor, M.A., Euler, W.B. Undergraduate NMR Laboratory Experiments. In NMR Concepts; Traficante, D.D. Ed.; NMR Concepts: Warwick, RI, 1995.
[4]	Gift A.D., Stewart S.M., and Bokashanga K.P., Experimental Determination of pKa Values by use of NMR Chemical Shifts, Revisited”, J. Chem. Educ. 89, 1458-1460, August 2012.
[5]	D’Amelia, R; Huang, L; Nirode, W; Rotman, E; Shumila, J; Wachter, N; “Application of 1H-NMR for the Quantitative Analysis of Short Chain Fatty Acid Methyl Ester Mixtures: An Undergraduate Instrumental Analysis Experiment”, World Journal of Chemical Education, April 2015.
[6]	Hoffmann M.M., Caccamis J.T., Heitz M.P., and Schlecht K.D., “Quantitative Analysis of Nail Polish Remover using Nuclear Magnetic Resonance Spectroscopy Revisited”, J. Chem. Educ., 85(10), 1421-1423, October 2008.
[7]	Clarke, D., “Acetone and Ethyl Acetate in Commercial Nail Polish Removers: A Quantitative NMR Experiment using an Internal Standard”, J. Chem. Educ., 74(12), 1464-1465, December 1997.
[8]	Peterson, J.,”1H NMR Analysis of Mixtures using Internal Standards”, J. Chem. Educ., 69, 843-845, October 1992.
[9]	Bauner, B. and Pringle, D. “Proton NMR Analysis of Heat Exchange Fluids Containing Ethylene Glycol, Propylene Glycol, and Water: A Real-World Experiment for the Analytical Laboratory”, J. Chem. Educ., 91, 743-746, April 2014.
[10]	Phillips J.S., Leary J.J., “A Qualitative – Quantitative 1H- NMR Experiment for the Instrumental Analysis Laboratory”, J. Chem. Educ., 63(6), 545-546, June 1986.
[11]	Podgorski, V.V., Milhalev, A.S., Kalabin, G.A., “Quantitative NMR Spectroscopy for the Quality control of Drugs and Pharmaceuticals, Phar. Chem.J., 45(3), 194-197, June 2011.
[12]	D’Amelia, R.P., Kimura, W. M., Villon, M-C., “Qualitative and Quantitative Analyses of Synthesized Short-Chain Fatty Acid Phenyl Esters using Fourier-Transform Infrared Spectroscopy” in the World Journal of Organic Chemistry, vol 9, # 1, pp. (2021).
[13]	D’Amelia, R.P., Kimura, W. M. Nirode, W. “Application of Quantitative Proton Nuclear Magnetic Resonance Spectroscopy for the Compositional Analysis of Short-Chain Fatty Acid Ethyl Ester Mixtures” in the World Journal of Chemical Education, vol 9, # 1, pp.8-13 (2021).
[14]	D’Amelia, R.P., Mancuso, J., Wachter N. “Application of Quantitative Proton Nuclear Magnetic Resonance Spectroscopy for the Compositional Analysis of Short Chain Fatty Acid Benzyl Ester Mixtures”, World Journal of Chemical Education, vol. 7, #3, pp. 189-195, (2019).