World Journal of Chemical Education
ISSN (Print): 2375-1665 ISSN (Online): 2375-1657 Website: http://www.sciepub.com/journal/wjce Editor-in-chief: Prof. V. Jagannadham
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World Journal of Chemical Education. 2021, 9(1), 8-13
DOI: 10.12691/wjce-9-1-2
Open AccessArticle

Application of Quantitative Proton Nuclear Magnetic Resonance Spectroscopy for the Compositional Analysis of Short-Chain Fatty Acid Ethyl Ester Mixtures

Ronald P. D'Amelia1, , Masashi W. Kimura1 and William F. Nirode1

1Chemistry Department, Hofstra University, Hempstead, NY

Pub. Date: November 20, 2020

Cite this paper:
Ronald P. D'Amelia, Masashi W. Kimura and William F. Nirode. Application of Quantitative Proton Nuclear Magnetic Resonance Spectroscopy for the Compositional Analysis of Short-Chain Fatty Acid Ethyl Ester Mixtures. World Journal of Chemical Education. 2021; 9(1):8-13. doi: 10.12691/wjce-9-1-2

Abstract

Nuclear magnetic resonance spectroscopy (NMR) is a widely used, powerful, and perhaps one of the most important instrumental techniques to qualitatively determine the molecular structure of an analyte. Using proton NMR in quantitative applications, also known as qNMR, is, however, uncommon, particularly in quantifying analytes within a mixture. To increase exposure to both qualitative and quantitative aspects of NMR in an undergraduate chemistry laboratory curriculum, we have developed a straightforward qNMR experiment suitable for adaptation into analytical and instrumental chemistry courses. The objective of this experiment is to determine the weight percent composition of a binary mixture containing short-chain fatty acid ethyl esters. We report on the methodologies used to determine the weight percent composition of ethyl acetate (EtAc), ethyl propionate (EtPr), and ethyl butyrate (EtBu) with mixtures ranging from 0% to 100%. The results demonstrate a strong, linear correlation of the weight percent composition of a selected component in a binary mixture found using proton qNMR with the theoretical compositions calculated gravimetrically. The experiment demonstrates the quantitative utility of proton NMR and serves as an educational tool for the undergraduate chemical laboratory.

Keywords:
quantitative analysis nuclear magnetic resonance proton NMR undergraduate laboratory experiment hands-on learning ethyl esters ethyl ester mixtures

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References:

[1]  Woodworth, J. K.; Terrance J. C.; Hoffmann, M. M. Using Nuclear Magnetic Resonance Spectroscopy for Measuring Ternary Phase Diagrams. J. Chem. Educ. 2006, 83(7), 1065-1066.
 
[2]  Isaac-Lam, M. F. Analysis of Bromination of Ethylbenzene using a 45MHz NMR Spectrometer: An Undergraduate Organic Chemistry Laboratory Experiment. J. Chem. Educ. 2014, 91(8), 1264-1266.
 
[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.; Steward S. M.; Bokashanga K. P. Experimental Determination of pKa Values by use of NMR Chemical Shifts, Revisited. J. Chem. Educ. 2012, 89(11), 1458-1460.
 
[5]  D'Amelia, R. P.; Huang, L.; Nirode, W. F.; Rotman, E.; Shumila, J.; Wachter, N. M. Application of 1H-NMR for the Quantitative Analysis of Short Chain Fatty Acid Methyl Ester Mixtures: An Undergraduate Instrumental Analysis Experiment. World J. Chem. Educ. 2015, 3(2), 46-50.
 
[6]  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 J. Chem. Educ. 2019, 7(3), 189-195.
 
[7]  Hoffmann, M. M.; Caccamis, J. T.; Heitz, M. P.; Schlecht, K. D. Quantitative Analysis of Nail Polish Remover using Nuclear Magnetic Resonance Spectroscopy Revisited. J. Chem. Educ. 2008, 85(10), 1421-1423.
 
[8]  Clarke, D. Acetone and Ethyl Acetate in Commercial Nail Polish Removers: A Quantitative NMR Experiment using an Internal Standard. J. Chem. Educ. 1997, 74(12), 1464-1465.
 
[9]  Peterson, J. 1H NMR Analysis of Mixtures using Internal Standards. J. Chem. Educ. 1992, 69(10), 843-845.
 
[10]  Bauner, B.; 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. 2014, 91(5), 743-746.
 
[11]  Phillips, J. S.; Leary, J. J. A Qualitative-Quantitative 1H-NMR Experiment for the Instrumental Analysis Laboratory. J. Chem. Educ. 1986, 63(6), 545-546.
 
[12]  Podgorski, V. V.; Milhalev, A. S.; Kalabin, G. A. Quantitative NMR Spectroscopy for the Quality Control of Drugs and Pharmaceuticals. Phar. Chem. J. 2011, 45(3), 194-197.