scholarly journals Polylactides with “green” plasticizers: Influence of isomer composition

2013 ◽  
Vol 130 (4) ◽  
pp. 2962-2970 ◽  
Author(s):  
Veluska Arias ◽  
Anders Höglund ◽  
Karin Odelius ◽  
Ann‐Christine Albertsson
Keyword(s):  
Isomer Composition

Differences in the isomer composition of perfluoroctanesulfonyl (PFOS) derivatives

2007 ◽  
Vol 42 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Sandhya M. Vyas ◽  
Izabela Kania-Korwel ◽  
Hans-Joachim Lehmler
Keyword(s):  
Isomer Composition

Isomer composition of the heteropolyacid H5PV2W10O40 according to31P and51V NMR data

1986 ◽  
Vol 35 (10) ◽  
pp. 1977-1981 ◽  
Author(s):  
R. I. Maksimovskaya ◽  
O. A. Subocheva ◽  
L. I. Kuznetsova
Keyword(s):  
Nmr Data ◽  
Isomer Composition

scholarly journals Gas-Liquid Chromatography–Mass Spectrometry Characterization of Polychlorinated Biphenyls (Aroclors) and 36Cl-Labeling of Aroclors 1248 and 1254

1971 ◽  
Vol 54 (4) ◽  
pp. 801-807
Author(s):  
David L Stalling ◽  
James N Huckins
Keyword(s):  
Mass Spectrometry ◽  
Aquatic Organisms ◽  
Sample Introduction ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Radioactive Materials ◽  
Isomer Composition ◽  
Temperature Programmed ◽  
Uptake And Metabolism

Abstract The isomer composition of the Aroclor 1200 series was characterized by GLC-MS, using temperature programming and SE-30 support-coated, open-tubular capillary columns. A method is described for the preparation and purification of 36Cl-labeled Aroclors 1248 and 1254. Neutron irradiation of the commercial material was used to prepare the 36Cl-labeled material. Purification of the irradiated product was accomplished by silicic acid column chromatography. Yields of the purified product were between 63 and 99%, with no detectable alteration of the isomer composition; 10% of the 36C1 produced was associated with the unchanged PCB isomers and the remaining radioactivity was contained in polychlorinated terphenyls. The terphenyls were produced by irradiation polymerization, and they were easily separated from the PCB components. Mass spectrometry, utilizing either temperature programmed GLC or direct probe sample introduction, was used to characterize the irradiation products. The radioactive materials are being utilized in experiments to determine uptake and metabolism of PCB by aquatic organisms.

Studies of the Uroporphyrins

1960 ◽  
Vol 6 (2) ◽  
pp. 71-97 ◽  
Author(s):  
C J Watson ◽  
M H Berg ◽  
V E Hawkinson ◽  
Irene Bossenmaier
Keyword(s):  
Calcium Carbonate ◽  
Ethyl Acetate ◽  
Extraction Procedure ◽  
Type I ◽  
Acute Porphyria ◽  
Preliminary Heating ◽  
Type Iii ◽  
Naturally Occurring ◽  
Isomer Composition ◽  
Metabolic Significance

Abstract 1. Seventeen cases of hepatic porphyria have been studied with respect to variations in isomer composition of the urinary Waldenström uroporphyrin complex. 2. Comparison was made of the effect of various isolation procedures on the isomer composition of the uroporphyrin complex, with special reference to the effect of preliminary heating of the urine. 3. Methods not employing heat, including the ethyl acetate extraction procedure of Waldenström, the talc adsorption of Grinstein et al., and a number of modifications, usually yielded relatively small amounts of a uroporphyrin complex, preponderantly Type I isomer. In two instances, however, the complex contained 60-70 per cent Type III. When separable on calcium carbonate, the Type III component was again shown to consist in the main of a 7-COOH porphyrin. Preheating of the urine regularly produced much larger amounts of a Waldenström type porphyrin, and larger proportions of Type III isomer in the complex. 4. The Waldenström porphyrin isolated following conversion of naturally occurring porphyrinogen, by irradiation with ultraviolet light, usually contained a marked preponderance of uroporphyrin I. In certain instances, however, the porphyrinogen was entirely that of the "208" Type III porphyrin. 5. While the large amount of Type III porphyrin found after heating the urine undoubtedly represents nonenzymatic conversion of porphobilinogen, the smaller amount of Type I isomer usually present in major proportion in the preformed uroporphyrin complex or its porphyrinogen may have intrinsic metabolic significance. In exceptional cases of acute porphyria, the uroporphyrin of the unheated urine is preponderantly the Type III isomer.

Changes in the milk and cheese fat composition of ewes fed commercial supplements containing linseed with special reference to the CLA content and isomer composition

Lipids ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 445-454 ◽  
Author(s):  
Pilar Luna ◽  
Javier Fontecha ◽  
Manuela Juárez ◽  
Miguel Angel de la Fuente
Keyword(s):  
Special Reference ◽  
Isomer Composition ◽  
Fat Composition

The PMR spectroscope study of the isomer composition of aromatic polyamic acids

1987 ◽  
Vol 29 (11) ◽  
pp. 2565-2572 ◽  
Author(s):  
A.N El'mesov ◽  
Yu.S Bogachev ◽  
I.L Zhuravleva ◽  
I.Ye Kardash
Keyword(s):  
Isomer Composition

scholarly journals Incremental effects of feeding a rumen-inert MUFA supplement to dairy cows on milk trans fatty acid isomer composition

2011 ◽  
Vol 70 (OCE4) ◽  
Author(s):  
K. E. Kliem ◽  
C. K. Reynolds ◽  
R. Kirkland ◽  
D. J. Humphries ◽  
C. E. Barratt ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Dairy Cows ◽  
Trans Fatty Acid ◽  
Fatty Acid Isomer ◽  
Isomer Composition

Influence of manufacturing conditions on the conjugated linoleic acid content and the isomer composition in ripened French Emmental cheese

2004 ◽  
Vol 71 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Silke Gnädig ◽  
Jean-François Chamba ◽  
Eric Perreard ◽  
Stéphane Chappaz ◽  
Jean-Michel Chardigny ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Dairy Product ◽  
Raw Milk ◽  
Linoleic Acid Content ◽  
Processing Temperature ◽  
Emmental Cheese ◽  
Propionic Acid Bacteria ◽  
Isomer Composition ◽  
Normal Processing

In a study of the evolution of conjugated linoleic acid (CLA) during cheese production, the influence of Emmental cheese processing on the CLA content and the CLA isomer composition was evaluated. The use of raw and thermised milk, changes of processing temperature and the effect of propionic acid bacteria (PAB) were investigated. The content of CLA in raw milk was 8·6±1·9 mg/g fat and in the ripened cheese at 70 d was 8·6±1·6 mg/g fat, under normal processing conditions. No changes in the CLA content and CLA isomer composition were observed during Emmental cheese manufacturing process. Changes in cooking and moulding temperatures did not influence the CLA content. CLA content of cheese made from microfiltered milk with two different Propionibacterium freudenreichii strains was very close to cheeses made without PAB. CLA levels seem to be stable in this type of dairy product under the conditions examined.

Substituent Parameters Impacting Isomer Composition and Optical Properties of Dihydroindolizine Molecular Switches

2014 ◽  
Vol 79 (12) ◽  
pp. 5586-5594 ◽  
Author(s):  
Matthew A. Bartucci ◽  
Jacob W. Ciszek
Keyword(s):  
Optical Properties ◽  
Molecular Switches ◽  
Isomer Composition

Quantitative Measurement of Isomer Composition in Polypentenamer Using Carbon-13 Nuclear Magnetic Resonance

1974 ◽  
Vol 7 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Charles J. Carman ◽  
Charles E. Wilkes
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantitative Measurement ◽  
Isomer Composition ◽  
Nuclear Magnetic
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