השוואת שיטות

	הד-ספין ב-NMR	ספקטרומטריית מס (Mass Spectrometry) מסוג FT-ICR	NOESY
תחום	ספקטרוסקופיה	ספקטרוסקופיה	ספקטרוסקופיה
משפחה	Process / pipeline	Process / pipeline	Process / pipeline
שנת המקור	1950	1974	1981
הוגה השיטה	Erwin Hahn	Alan Marshall	Richard Ernst
סוג	Spectroscopic pulse sequence	Mass spectrometry technique	Two-dimensional pulse sequence
מקור מכונן	Hahn, E. L. (1950). Spin echoes. Physical Review, 80(4), 580-594.	Comisarow, M. B., & Marshall, A. G. (1974). Fourier transform ion cyclotron resonance spectroscopy. Chemical Physics Letters, 25(2), 282-283.	Aue, W. P., Bartholdi, E., & Ernst, R. R. (1976). Two-dimensional spectroscopy. Application to nuclear magnetic resonance. The Journal of Chemical Physics, 64(5), 2229-2246.
כינויים	CPMG pulse sequence, spin-echo NMR	FT-ICR-MS, Fourier Transform ICR, ICR mass spectrometry	NOE spectroscopy, 2D NOESY, NOE NMR
קשורות	4	4	3
תקציר	The spin-echo is a fundamental nuclear magnetic resonance (NMR) pulse sequence technique introduced by Erwin Hahn in 1950. It uses a 90-degree radiofrequency pulse followed by a 180-degree refocusing pulse to create an echo, effectively reversing the effects of magnetic field inhomogeneities and allowing accurate measurement of spin relaxation properties. This technique is essential in modern NMR spectroscopy for both one-dimensional and multidimensional experiments.	Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry is an advanced analytical technique that combines magnetic confinement of ions with Fourier transform data processing to achieve exceptional mass accuracy and resolution. Developed by Comisarow and Marshall in 1974, FT-ICR-MS enables the determination of exact masses and elemental compositions of complex molecules, making it invaluable for environmental chemistry, metabolomics, petroleum characterization, and structural elucidation of unknowns.	Nuclear Overhauser Enhancement Spectroscopy (NOESY) is a 2D NMR technique that detects through-space dipolar coupling between protons, rather than through-bond scalar coupling. Introduced by Macura and Ernst in 1981, NOESY reveals which protons are spatially close in the three-dimensional structure, independent of bonding connectivity. This makes NOESY invaluable for determining molecular conformation, assigning stereochemistry, and elucidating protein folds.