Application of automated eightfold suppression of water and ethanol signals in 1H NMR to provide sensitivity for analyzing alcoholic beverages

Application of automated eightfold suppression of water and ethanol signals in 1H NMR to provide sensitivity for analyzing alcoholic beverages

Copyright © 2011 John Wiley & Sons, Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Magnetic resonance in chemistry : MRC. - 1985. - 49(2011), 11 vom: 16. Nov., Seite 734-9
1. Verfasser: Monakhova, Yulia B (VerfasserIn)
Weitere Verfasser: Schäfer, Hartmut, Humpfer, Eberhard, Spraul, Manfred, Kuballa, Thomas, Lachenmeier, Dirk W
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2011
Zugriff auf das übergeordnete Werk:Magnetic resonance in chemistry : MRC
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Protons Water 059QF0KO0R Ethanol 3K9958V90M
Beschreibung
Zusammenfassung:Copyright © 2011 John Wiley & Sons, Ltd.
The 400 MHz (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 the eight (1)H NMR frequencies of water and ethanol (the OH singlet of both water and ethanol, as well as the CH(2) quartet and CH(3) triplet of ethanol). The sequence of reference measurement for frequency determination followed by the suppression experiment is controlled by a macro in the acquisition software so that a measurement under full automation is possible (12 min per sample total time). Additionally, sample preparation was optimized to avoid precipitation, which is facilitated by 1:1 dilution with ethanol and pH 7.4 buffer. Compared with the standard water presaturation pulse program, the eightfold suppression allowed a significantly higher setting of receiver gain without receiver overflow, which significantly increased the signal-to-noise ratio by an average factor of 10. The signal intensities increased by a factor of 20. The resulting limits of detection (below 1 g/hl of pure alcohol) now allow the control of legal requirements for minor compounds in alcoholic beverages
Beschreibung:Date Completed 28.02.2012
Date Revised 21.11.2013
published: Print-Electronic
Citation Status MEDLINE
ISSN:1097-458X
DOI:10.1002/mrc.2823