title: Suppressing background signals in solid state NMR via the Electronic Mixing-Mediated Annihilation (EMMA) method.
abstract: A simple procedure to effectively suppress background signals arising from various probe head components (e.g. stator, rotors, inserts) in solid state NMR is presented. Similarly to the ERETIC™ method, which uses an electronic signal as an internal standard for quantification, the proposed scheme is based on an electronically generated time-dependent signal that is injected into the receiver coil of the NMR probe head during signal acquisition. More specifically, the line shape, width and frequency of this electronic signal are determined by deconvoluting the background signal in the frequency domain. This deconvoluted signal is then converted into a time-dependent function through inverse Fourier Transform, which is used to generate the shaped pulse that is fed into the receiver coil during the acquisition of the Free Induction Decay. The power of the shaped pulse is adjusted to match the intensity of the background signal, and its phase is shifted by 180° with respect to the receiver reference phase. This so-called Electronic Mixing-Mediated Annihilation (EMMA) methodology is demonstrated here with a (13)C Single Pulse Magic Angle Spinning spectrum of an isotopically enriched (13)C histidine solid sample recorded under quantitative conditions.
authors.affiliation: Aix-Marseille Univ. & CNRS, Institut de Chimie Radicalaire UMR 7273, Equipe Spectrométries Appliquées à la Chimie Structurale, av. Escadrille Normandie Niémen, case 512, F-13013 Marseille, France.
authors.forename: Giulia
authors.initials: G
authors.lastname: Mollica
authors.forename: Fabio
authors.initials: F
authors.lastname: Ziarelli
authors.forename: Aura
authors.initials: A
authors.lastname: Tintaru
authors.forename: Pierre
authors.initials: P
authors.lastname: Thureau
authors.forename: Stéphane
authors.initials: S
authors.lastname: Viel
mesh_terms: D000465:Algorithms; D002247:Carbon Isotopes; D005583:Fourier Analysis; D006639:Histidine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000032:analysis; D012984:Software
chemical_list: D002247:Carbon Isotopes; D004364:Pharmaceutical Preparations; D006639:Histidine