title: Precision and sensitivity optimization of quantitative measurements in solid state NMR.
abstract: This work presents a methodology for optimizing the precision, accuracy and sensitivity of quantitative solid state NMR measurements based on the external reference method. It is shown that the sample must be exclusively located within and completely span the coil region where the NMR response is directly proportional to the sample amount. We describe two methods to determine this "quantitative" coil volume, based on whether the probe is equipped or not with a gradient coil. In addition, to improve the sensitivity and the accuracy, an optimum rotor packing design is described, which allows the sample volume of the rotor to be matched to the quantitative coil volume. Experiments conducted on adamantane and NaCl, which are representative of a soft and hard material, respectively, show that one order of magnitude increase in experimental precision can be achieved with this methodology. Interestingly, the precision can be further improved by using the ERETIC method in order to compensate for most instrumental instabilities.
authors: CNRS, Fédération des Sciences Chimiques de Marseille, Spectropole, Service 511, av Escadrille Normandie Niémen, 13397, Marseille Cedex 20, France. fabio.ziarelli@univ-cezanne.fr
authors: Fabio
authors: F
authors: Ziarelli
authors: Stéphane
authors: S
authors: Viel
authors: Stéphanie
authors: S
authors: Sanchez
authors: David
authors: D
authors: Cross
authors: Stefano
authors: S
authors: Caldarelli
mesh_terms: D000218:Adamantane / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D012965:Sodium Chloride; D000218:Adamantane