Experimental Methods in Chemical Engineering: Nuclear Magnetic Resonance

• Published in: Canadian journal of chemical engineering 2019-03, Vol.97 (3), p.628-635
• Main Authors: Rigamonti, Marco G., Gatti, Francesco G., Patience, Gregory S.
• Format: Article
• Language: English
• Subjects: Analytical method; Aqueous solutions; benchtop NMR; bibliometric network; Chemical bonds; Chemical engineering; Chemical sensors; Chemoreceptors; Cluster analysis; cost; Crystal structure; Density functional theory; detection limit; Drug delivery systems; Error detection; Experimental methods; Functional groups; Ionic liquids; Magnetic induction; Magnets; Molecular structure; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nuclei (nuclear physics); Organic chemistry; Polymers; Radio frequency; Reaction kinetics; Research methodology; Stability analysis; X-ray diffraction
• ISSN: 0008-4034; 1939-019X
• DOI: 10.1002/cjce.23409

Nuclear magnetic resonance (NMR) spectroscopy measures free induction decay (FID) signals that atomic nuclei emit when excited by a radio‐frequency (RF) pulse in a static magnetic field. The Fourier‐transformed spectrum shows chemically shifted peaks, area intensity, and multiplicity, which give information on molecular structure, bonds, functional groups, and purity. Web of Science Core Collection indexed 46 000 articles that mentioned NMR in 2016 and 2017. The VosViewer software grouped the research into 5 clusters: solid‐state analysis including metabolomics; biology with in‐vitro and antibacterial applications; coupled analytical techniques to identify crystal structure for which x‐ray diffraction and density functional theory figure prominently; liquid‐state analysis for polymers, aqueous solutions, nano‐particles, and drug delivery; and chemosensors. Researchers publishing in The Canadian Journal of Chemical Engineering focus most on: liquid‐state NMR to characterize polymers, branching, and monomers; quantify conformation, reaction kinetics, and equilibrium; and assess surfactant stability, ionic liquids, and composition. We introduce the theory behind NMR spectroscopy and common applications in chemistry and material science. We highlight the strength and limitations, sources of error, and the detection limit for this analytical technique, as manufacturers develop massive magnets for high‐resolution spectra (1 GHz), and benchtop NMR for real‐time, in‐situ analysis (80 MHz).