Fractional volume integration in two-dimensional NMR spectra: CAKE, a Monte Carlo approach.
J Magn Reson
; 192(2): 294-301, 2008 Jun.
Article
en En
| MEDLINE
| ID: mdl-18396078
ABSTRACT
Quantitative information from multi-dimensional NMR experiments can be obtained by peak volume integration. The standard procedure (selection of a region around the chosen peak and addition of all values) is often biased by poor peak definition because of peak overlap. Here we describe a simple method, called CAKE, for volume integration of (partially) overlapping peaks. Assuming the axial symmetry of two-dimensional NMR peaks, as it occurs in NOESY and TOCSY when Lorentz-Gauss transformation of the signals is carried out, CAKE estimates the peak volume by multiplying a volume fraction by a factor R. It represents a proportionality ratio between the total and the fractional volume, which is identified as a slice in an exposed region of the overlapping peaks. The volume fraction is obtained via Monte Carlo Hit-or-Miss technique, which proved to be the most efficient because of the small region and the limited number of points within the selected area. Tests on simulated and experimental peaks, with different degrees of overlap and signal-to-noise ratios, show that CAKE results in improved volume estimates. A main advantage of CAKE is that the volume fraction can be flexibly chosen so as to minimize the effect of overlap, frequently observed in two-dimensional spectra.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Oligopéptidos
/
Espectroscopía de Resonancia Magnética
/
Método de Montecarlo
/
Hormona Liberadora de Tirotropina
Tipo de estudio:
Health_economic_evaluation
/
Prognostic_studies
Idioma:
En
Revista:
J Magn Reson
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2008
Tipo del documento:
Article