Determination of nitrate isotopic signature in waters of different sources by analysing the nitrogen and oxygen isotopic ratio

2013 ◽  
Vol 15 (4) ◽  
pp. 751 ◽  
Author(s):  
Piotr Koszelnik ◽  
Renata Gruca-Rokosz
Keyword(s):  
Isotopic Ratio ◽  
Isotopic Signature ◽  
Oxygen Isotopic ◽  
Different Sources ◽  
Oxygen Isotopic Ratio

Stepwise Fluorination Method for Determination of Oxygen Isotopic Ratio of Diatoms

2013 ◽  
Vol 40 (12) ◽  
pp. 1897-1901
Author(s):  
Tie-Jun LI ◽  
Hong-Wei LI ◽  
Xiu-Jin LIU ◽  
Lian-Jun FENG
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
Oxygen Isotopic Ratio

METABOLISM OF OESTRONE AND OESTRADIOL IN THE HUMAN FOETO-PLACENTAL UNIT AT MIDPREGNANCY

1965 ◽  
Vol 49 (1) ◽  
pp. 65-82 ◽  
Author(s):  
J. Schwers ◽  
G. Eriksson ◽  
E. Diczfalusy
Keyword(s):  
Isotopic Ratio ◽  
Umbilical Vein ◽  
Radioactive Material ◽  
Isotopic Ratios ◽  
Therapeutic Abortion ◽  
Main Site ◽  
Foetal Liver ◽  
Different Sources

ABSTRACT In four cases of therapeutic abortion by laparotomy, tracer amounts of oestrone-6,7-3H and 17β-oestradiol-16-14C were injected into the umbilical vein 20 minutes prior to the interruption of gestation, and the radioactive material recovered from the placenta and various foetal tissues was analysed. More than 92 per cent of the radioactive material recovered from the foetus, but less than 15 per cent of that present in the placenta, was in a conjugated form. Among the foetal tissues studied, the highest percentage of unconjugated (free) radioactive material (25 per cent) occurred in the adrenals. Determination of the isotopic ratios revealed that complete interconversion of injected material was approached only by the oestrone and 17β-oestradiol isolated from the conjugated fraction of the liver. Approximately 10 per cent of the radioactive material recovered from the foetal liver and smaller amounts of that found in the placenta and residual foetal tissues were isolated and identified as oestriol. The isotopic ratio of oestriol isolated from different sources approached very closely that of conjugated oestrone and 17β-oestradiol in the foetal liver, but was distinctly different from the isotopic ratio of free and conjugated oestrone and 17β-oestradiol in all other tissues. At least 9 additional metabolites were detected in the conjugated fraction of the foetal liver. One of them was identified as 15α-hydroxy-17β-oestradiol, another one as 16- (or possibly 17-) epioestriol, and two were ring D ketolic oestrogens, most probably 16α-hydroxyoestrone and 16-oxo-17β-oestradiol. The isotopie ratios of all identified compounds were similar to those of oestrone and 17β-oestradiol isolated from the same fraction. It is concluded that in the foeto-placental unit at midpregnancy, the liver is the main site of oestrone and 17β-oestradiol metabolism and that this metabolism takes place predominantly in a conjugated form, most probably in form of 3-sulphates.

Variation of oxygen isotopic ratio during wine dealcoholization by membrane contactors: Experiments and modelling

2016 ◽  
Vol 498 ◽  
pp. 385-394 ◽  
Author(s):  
Roberto Ferrarini ◽  
Gian Maria Ciman ◽  
Federica Camin ◽  
Serena Bandini ◽  
Carlo Gostoli
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
Membrane Contactors ◽  
Oxygen Isotopic Ratio

scholarly journals Preparation and storage of “laboratory standard” for measurement of hydrogen and oxygen isotopic ratio

2015 ◽  
Vol 57 (3) ◽  
pp. 295-306
Author(s):  
Kotaro NAKATA ◽  
Takuma HASEGAWA ◽  
Mari YOSHIOKA ◽  
Takahiro IIDA
Keyword(s):  
Isotopic Ratio ◽  
Oxygen Isotopic ◽  
And Storage ◽  
Oxygen Isotopic Ratio

scholarly journals Wine origin authentication linked to terroir – wine fingerprint

2019 ◽  
Vol 15 ◽  
pp. 02033
Author(s):  
B. Gabel
Keyword(s):  
Pore Water ◽  
Isotope Composition ◽  
Food Product ◽  
Isotopic Signature ◽  
Original Method ◽  
Economic Problem ◽  
Red Wines ◽  
Table Grapes ◽  
Mineral Phases

Global wine and alcohol trade faces a serious economic problem linked to counterfeiting of these commodities. Recently applied authentication methods and techniques pose more difficulties for counterfeiters but they are apparently not effective once we consider economical losses identified by EU legal authorities. The presented solution links isotopic characteristics of the soil, plant, technological intermediate product and the final food product (wine, grapes) on the basis of 87Sr/86Sr isotopes ratios. For the isotopic signature of wines, the average isotope composition of the substrate cannot be a reliable indicator. Only the isotopic composition of pore water can, as it leaches various mineral phases at different stages and passes into vine root system. Instead of complicated sampling of pore water, an original method of preparing and processing soil samples and consequently must & wine samples was developed. Based on both, soil and biological material analysis, we can unquestionably determine not only geographical but also regional and local authenticity of the wine. Determination of red wines isotopic signature is more straightforward process in comparison to white wines, because of technologically different processing of grapes. That is the reason why, in case of white vines, the 87Sr/86Sr ratio of bentonites (natural purifier and absorbent useful in the process of winemaking) must also be taken into consideration. Results of analyses of Slovak wines from geographically diverse regions as well as from sites in close-by distances have clearly established reliability of presented concept, in which the soil is linked to the plant and to the final food product (wine or table grapes).

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