Direct Qualitative and Quantitative Analysis of Triterpenes Using 13C NMR Spectroscopy Exemplified by Dichloromethanic Extracts of Cork

1999 ◽  
Vol 53 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Vincent Castola ◽  
Ange Bighelli ◽  
Joseph Casanova
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative

scholarly journals Secondary metabolites of three endemic Centaurea L. species

2014 ◽  
Vol 79 (11) ◽  
pp. 1355-1362 ◽  
Author(s):  
Vele Tesevic ◽  
Ivana Aljancic ◽  
Slobodan Milosavljevic ◽  
Vlatka Vajs ◽  
Iris Djordjevic ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
Secondary Metabolites ◽  
Sesquiterpene Lactone ◽  
1H Nmr ◽  
13C Nmr ◽  
1H Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Esi Ms ◽  
Aerial Parts

The aerial parts of three endemic Centaurea L. species, namely C. tomorosii Micevski, C. soskae Hayek and C. galicicae Micevski, afforded sesquiterpene lactone cnicin (1) and seven flavonoids: apigenin (2), isokaempferide (3), hispidulin (4), eupatorin (5), cirsimaritin (6), santaflavone (7) and salvigenin (8). The structures of the isolated compounds were determined by UV, 1H NMR and 13C NMR spectroscopy and HR-ESI-MS spectrometry. 1H NMR spectroscopy was used as a method for quantitative analysis of sesquiterpene lactone cnicin.

Analysis of marine dietary supplements using NMR spectroscopy

2015 ◽  
Vol 7 (12) ◽  
pp. 5226-5238 ◽  
Author(s):  
Photis Dais ◽  
Maria Misiak ◽  
Emmanuel Hatzakis
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Fish Oil ◽  
Dietary Supplements ◽  
Multidimensional Nmr ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
Multidimensional Nmr Spectroscopy

The objective of this study is the qualitative and quantitative analysis of encapsulated fish oil supplements by utilizing high-resolution multinuclear (1H,13C,31P) and multidimensional NMR spectroscopy.

scholarly journals 29Si AND 27Al CPMAS NMR QUALITATIVE AND QUANTITATIVE ANALYSIS OF KAOLINITE AND DICKITE IN KOS ISLAND KAOLINS, GREECE

2007 ◽  
Vol 40 (2) ◽  
pp. 936
Author(s):  
D. Papoulis
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Qualitative And Quantitative Analysis ◽  
Group Mineral ◽  
Qualitative And Quantitative ◽  
Exact Position ◽  
Structural Formulae ◽  
First Time

The application of 27Al and 29Si CPMAS NMR spectroscopy to the investigation of selected /caolinite and dickite bearing samples from hydrothermally altered rhyolites of Kos island is tested using also XRD and analytical SEM-EDS data. Kaolinite and dickite, can be detected by both their tetrahedral Si and octahedral Al CPMAS NMR spectra. It was found that the interference of the peaks become less significant and the shape of the peaL· narrow when the pulse recycling delay is high (up to 10s). The octahedral Al / tetrahedral Si ratios of kaolinite group mineral forms from samples showing various degrees of alteration, calculated from the NMR spectra, were found to be very similar to these derived from the structural formulae of SEM-EDS microanalyses. In this work it is presented for the first time an approach to provide narrow CPMAS NMR peaks. The narrow shape of the peaks provides accurate measurements of the exact position of the peaL· and the octahedral Al / tetrahedral Si ratios.

Sign in / Sign up

Export Citation Format

Share Document