scholarly journals Miniaturized QC and TDL laser spectrometers for biogenic gases and isotope ratios on Mars, Titan, and Venus

2002 ◽  
Author(s):  
Chris Webster
Keyword(s):  
Isotope Ratios

Plagioclase weathering by mycorrhizal plants in a Ca-depleted catchment, inferred from Nd isotope ratios and REE composition

2017 ◽  
Vol 51 (6) ◽  
pp. 537-550
Author(s):  
Tasuku Akagi ◽  
Tomohiro Miura ◽  
Rie Takada ◽  
Kazuo Watanabe
Keyword(s):  
Isotope Ratios ◽  
Nd Isotope ◽  
Mycorrhizal Plants

TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Secondary Production ◽  
Isotope Ratios ◽  
Ruditapes Philippinarum ◽  
Transfer Efficiency ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Primary Producers ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

Authenticity of sugar – Identification of plant source and determination of geographical origin of sucrose

2015 ◽  
pp. 40-43 ◽  
Author(s):  
Andreas G. Degenhardt
Keyword(s):  
Metabolic Pathways ◽  
Isotope Ratio ◽  
Geographical Origin ◽  
Hydrological Cycle ◽  
Isotope Ratios ◽  
Saccharum Officinarum ◽  
Mass Spectrometric ◽  
C3 And C4 Plants ◽  
Plant Source

The isotope ratios of water, organic matter and micronutrients from food are dependent on the circumstances and sites of their origin and production. Analytical methods, based on mass spectrometry, are established for routine determination of isotopes. Differentiation between metabolic pathways of C3 and C4 plants is realizable by determination 13C/12C ratios which can distinguish and identify sucrose from pure beet (Beta vulgaris) and pure cane (Saccharum officinarum). Influenced by the worldwide hydrological cycle the isotope ratios of 2H/1H and 18O/16O vary systematically, the variations give information about geographical origin. The exemplarily determination of authenticity is demonstrated by using mass spectrometric isotope ratio evaluation for identification of plant source and geographical origin with the help of selected sugar samples with known origin.

Authenticity of speciality sugars – Determination of carbohydrate source and geographical origin of invert sugar syrup and burnt sugar syrup

2017 ◽  
pp. 87-91
Author(s):  
Andreas G. Degenhardt ◽  
Elke Jansen ◽  
Timo, J. Koch
Keyword(s):  
Geographical Origin ◽  
Hydrological Cycle ◽  
Isotope Ratios ◽  
Saccharum Officinarum ◽  
Invert Sugar ◽  
C4 Plants ◽  
Yeast Fermentation ◽  
Carbohydrate Source ◽  
Sugar Syrup

Modern instrumental analytical methods for the determination of 13C/12C ratios are established to differentiate between metabolic products of C3 and C4 plants. Differentiation and identification of sucrose from pure beet (Beta vulgaris) and pure cane (Saccharum officinarum) are possible without doubt. Influenced by the worldwide hydrological cycle the determination of the isotope ratios of 2H/1H and 18O/16O as well as their variations provide information about geographical origin. Using samples of selected crystal cane sugar (CCS) with known origin, invert sugar syrups (ISS) as well as burnt sugar syrups (BSS) produced therefrom, the authenticity was determined. The speciality sugars ISS and BSS which were made from CCS could be identified as carbohydrates of C4 plants by using 13C/12C Isotope-Ratio Mass Spectrometry (IRMS). In combination with yeast fermentation of ISS and sugar separation from BSS and fermentation into ethanol as well as knowledge about production water, the C2-H/O isotope ratios of ethanol can theoretically determine the geographical origin of the sugars.

Relationship between copper tonnage of Chilean base-metal porphyry deposits and Os isotope ratios

Geology ◽  
2000 ◽  
Vol 28 (6) ◽  
pp. 555-558
Author(s):  
Ryan Mathur ◽  
Joaquin Ruiz ◽  
Francisco Munizaga
Keyword(s):  
Base Metal ◽  
Isotope Ratios ◽  
Porphyry Deposits ◽  
Os Isotope
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