## Abstract Longitudinal water proton relaxation rates of methemoglobin solutions show a strong dependence on temperature and pH. The increase of the relaxation rates with temperature is associated with shortened exchange lifetime of the coordinated water molecule. An accurate measurement of the re
An algorithm for the automated quantitation of metabolites in in vitro NMR signals
โ Scribed by Greg Reynolds; Martin Wilson; Andrew Peet; Theodoros N. Arvanitis
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 413 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0740-3194
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
The quantitation of metabolite concentrations from in vitro NMR spectra is hampered by the sensitivity of peak positions to experimental conditions. The quantitation methods currently available are generally labor intensive and cannot readily be automated. Here, an algorithm is presented for the automatic time domain analysis of highโresolution NMR spectra. The TARQUIN algorithm uses a set of basis functions obtained by quantum mechanical simulation using predetermined parameters. Each basis function is optimized by subdividing it into a set of signals from magnetically equivalent spins and varying the simulated chemical shifts of each of these groups to match the signal undergoing analysis. A novel approach to the standard multidimensional minimization problem is introduced based on evaluating the fit resulting from different permutations of possible chemical shifts, obtained from oneโdimensional searches. Results are presented from the analysis of ^1^H proton magic angle spinning spectra of cell lines illustrating the robustness of the method in a typical application. Simulation was used to investigate the biggest peak shifts that can be tolerated. Magn Reson Med, 2006. ยฉ 2006 WileyโLiss, Inc.
๐ SIMILAR VOLUMES
The 400โMHz ^1^H NMR analysis of alcoholic beverages using standard pulse programs lacks the necessary sensitivity to detect minor constituents such as methanol, acetaldehyde or ethyl acetate. This study investigates the application of a shaped pulse sequence during the relaxation delay to suppress
An approximation technique for the calculation of pulsed-gradient experiment. We have also recently initiated a study of the NMR signals in confined spaces is introduced on the basis of a theoretical description of these issues with the help of a new memory-function formalism and compared to the wel