scholarly journals Computer-assisted analysis system of 13C-NMR spectra designed for composition determination of organic mixtures - Application to cosmetic products.

1986 ◽  
Vol 20 (3) ◽  
pp. 180-185
Author(s):  
Fumiyo Mochizuki ◽  
Keiichi Honda ◽  
Tohru Yoneya
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Computer Assisted ◽  
13C Nmr Spectra ◽  
Cosmetic Products ◽  
Organic Mixtures ◽  
Composition Determination ◽  
Analysis System ◽  
Assisted Analysis

scholarly journals Computer-assisted structural analysis of organic compounds from 13C-NMR spectra.

1994 ◽  
Vol 43 (7) ◽  
pp. 517-524
Author(s):  
Keiji SAITO ◽  
Yoshiaki ISHIDA ◽  
Tokio OOSHIMA
Keyword(s):  
Structural Analysis ◽  
Organic Compounds ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Computer Assisted ◽  
13C Nmr Spectra

Computer-aided determination of microfragmentary composition of organic molecule by mass-, 1H- and 13C-NMR spectra

1994 ◽  
Vol 18 (1) ◽  
pp. 81-88
Author(s):  
B.G. Derendyaev ◽  
K.S. Lebedev ◽  
S.A. Nekhorshev ◽  
S.P. Kirshansky
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Organic Molecule ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Computer Aided

Determination of the Structure of Chlorobutyl and Bromobutyl Rubber by NMR Spectroscopy

1987 ◽  
Vol 60 (4) ◽  
pp. 636-646 ◽  
Author(s):  
Chia Yeh Chu ◽  
Kenneth Norman Watson ◽  
Rastko Vukov
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Broad Band ◽  
Type Structure ◽  
13C Nmr Spectra ◽  
Model Compounds ◽  
1H And 13C Nmr

Abstract An analysis of the 1H and 13C NMR spectra of the chlorobutyl and bromobutyl rubbers was performed. Peaks were assigned based on evidence from broad-band decoupled, off-resonance decoupled, selectively decoupled and J-modulated spectra, the known characterization of butyl rubber and halogenation studies on model compounds. The assignment of the minor peaks indicated that the exomethylene-type structure is predominant in both halogenated rubbers. They also contain some nonhalogenated isoprenyl units. Bromobutyl rubber also contains some α-bromomethyl-type structures resulting from rearrangement of the exomethylene structure. The presence of endo-type structures will require further study for confirmation.

scholarly journals Modeling of Antioxidant Activity, Polyphenols and Macronutrients Content of Bee Pollen Applying Solid-State 13C NMR Spectra

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1123
Author(s):  
Sylwester Mazurek ◽  
Roman Szostak ◽  
Mateusz Kondratowicz ◽  
Magdalena Węglińska ◽  
Agnieszka Kita ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Bee Pollen ◽  
Relative Standard ◽  
Solid State 13C Nmr

An application of solid 13C nuclear magnetic resonance (NMR) spectroscopy for the determination of macronutrients, total polyphenols content, antioxidant activity, N C S elements, and pH in commercially available bee pollens is reported herein. Solid-state 13C NMR spectra were recorded for homogenized pollen granules without chemical treatment or dissolution of samples. By combining spectral data with the results of reference analyses, partial least squares models were constructed and validated separately for each of the studied parameters. To characterize and compare the models’ quality, the relative standard errors of prediction (RSEP) were calculated for calibration and validation sets. In the case of the analysis of protein, fat and reducing sugars, these errors were in the 1.8–2.5% range. Modeling the elemental composition of bee pollen on the basis of 13C NMR spectra resulted in RSEPcal/RSEPval values of 0.3/0.6% for the sum of NHCS elements, 0.3/0.4% for C, 1.8/1.9% for N, and 4.2/6.1% for S quantification. Analyses of total phenolics and ABTS antioxidant activity resulted in RSEP values in the 2.7–3.5% and 2.8–3.8% ranges, respectively, whereas they were 1.4–2.1% for pH. The obtained results demonstrate the usefulness of 13C solid-state NMR spectroscopy for direct determination of various important physiochemical parameters of bee pollen.

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