GAS ION SOURCE PERFORMANCE OF THE ENVIRONMICADAS AT HEKAL LABORATORY, DEBRECEN, HUNGARY

Radiocarbon ◽  
2021 ◽  
Vol 63 (2) ◽  
pp. 499-511
Author(s):  
Mihály Molnár ◽  
Marianna Mészáros ◽  
Róbert Janovics ◽  
István Major ◽  
Katalin Hubay ◽  
...  
Keyword(s):  
Carbon Isotopic Composition ◽  
Ion Source ◽  
Standard Samples ◽  
Carbon Isotopic ◽  
Accelerator Mass Spectrometer ◽  
Interface System ◽  
System Data ◽  
Gas Targets ◽  
Relative Errors ◽  
Good Agreement

ABSTRACTA coupled accelerator mass spectrometer–gas interface system has been successfully operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary, since 2013. Over the last 6 years more than 500 gas targets were measured below 100 µg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2, and IAEA-C7 standards. The performance of our instrumentation shows good agreement with other published gas-interface system data and also shows a quite good agreement with the nominal value of international standard samples. There is a measurable but quite small memory effect after modern samples, but this does not significantly affect the final results. Typical ion currents at the low energy side were between 10–15 µA with a 5% CO2 in He mixing ratio. The relative errors average ±6% for samples greater than or equal to 10 µgC sample with mean count rates of 300 counts per microgram C for OxII. The blank is comparable with other systems, which is 0.0050 ± 0.0018 F14C or 34,000–47,000 yr BP, which allows for the routine measurement of both of small environmental and archeological samples.

EnvironMICADAS C-14 AMS Gas ion source performance and its applications at HEKAL Laboratory, Debrecen, Hungary

2020 ◽  
Author(s):  
Mihály Molnár ◽  
Róbert Janovics ◽  
István Major ◽  
Katalin Hubay ◽  
Botond Buró ◽  
...  
Keyword(s):  
Carbon Isotopic Composition ◽  
Hungarian Academy ◽  
Ion Source ◽  
The European Union ◽  
Standard Samples ◽  
Development Fund ◽  
Carbon Isotopic ◽  
Interface System ◽  
Gas Targets ◽  
Good Agreement

<p>A coupled accelerator mass spectrometer - gas interface system successfully has been operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary since 2013. Over the last 6 years more than 500 gas targets were measured below 100 µg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2 and IAEA-C7 standards. The performance of our instrumentation shows good agreement with other published gas-interface system data and also shows a quite good agreement with the nominal value of international standard samples.  There is a measurable but quite small memory effect after modern samples, but this does not significantly affect the final results. Typical ion currents at the low energy side were between 10-15 µA with a 5% CO<sub>2</sub> in He mixing ratio. The relative errors average ±6% for samples greater than or equal to 10 µgC sample with mean count rates of 300 counts per microgram C for OxII. The blank is comparable with other systems, which is 0.0050 ± 0.0018 F<sup>14</sup>C or 34000-47000 yr BP, which allows for the routine measurement of both of small environmental and archeological samples.</p><p>The research was supported by the European Union and the State of Hungary, co-financed by the European Regional Development Fund in the project of GINOP-2.3.2-15-2016- 00009 “ICER”. This work was carried out in the frame of the János Bolyai Research Scholarship (Mihály Molnár) of the Hungarian Academy of Sciences</p>

scholarly journals The Tunguska Event as Recorded in a Tree Trunk

Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 367-371 ◽  
Author(s):  
Hitoshi Yonenobu ◽  
Chisato Takenaka
Keyword(s):  
Annual Ring ◽  
Carbon Isotopic Composition ◽  
Ring Width ◽  
Annual Ring Width ◽  
Hinoki Cypress ◽  
Carbon Isotopic ◽  
Significant Difference ◽  
Accelerator Mass Spectrometer ◽  
Tunguska Event ◽  
Tunguska Explosion

A living spruce tree was collected near the explosion center of the Tunguska event that occurred in 1908. We measured annual ring width and studied anatomical features to reconstruct the possible vegetational changes caused by the biological aftereffects of the Tunguska explosion. δ14C of annual rings from 1908 to 1910 was measured with a Tandetron accelerator mass spectrometer. The annual ring width decreased rapidly in 1908–1912, drastically increased in 1913, and decreased gradually thereafter. Traumatic resin ducts were observed in the transition zone between early- and latewood of the annual ring formed in 1908. We thus reconstruct these vegetational changes in the Tunguska forest: the Tunguska explosion damaged forest trees severely for ca. 3 yr, releasing rich nutrients from burned plants into the soil, and subsequently the vegetation was stimulated to recover by decreased socio-biological competition and better lighting conditions. δ14C values range from −28.2 to −1.5% for Tunguska spruce, and from −29.7 to 12.6% for Hinoki cypress. These fluctuations are within the ranges presented in Stuiver and Becker (1993), suggesting no evidence of anomalies of cometary origin in carbon isotopic composition. We found no significant difference between δ14C of Tunguska spruce and of Hinoki cypress.

New equation to decipher the relationship between carbon isotopic composition of methane and maturity of gas source rocks

2021 ◽  
Vol 64 (3) ◽  
pp. 470-493 ◽  
Author(s):  
Jianping Chen ◽  
Xulong Wang ◽  
Jianfa Chen ◽  
Yunyan Ni ◽  
Baoli Xiang ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopic Composition ◽  
Source Rocks ◽  
Carbon Isotopic ◽  
Gas Source ◽  
New Equation ◽  
The Relationship

Collaborative Study of a Titrimetric Method for the Assay of Amitrole Formulations

1967 ◽  
Vol 50 (3) ◽  
pp. 568-572
Author(s):  
J Russell Bishop
Keyword(s):  
Collaborative Study ◽  
Statistical Analyses ◽  
Standard Samples ◽  
Titrimetric Method ◽  
Inflection Points ◽  
Good Agreement

Abstract titrimetric method for the assay of dry and liquid amitrole formulations was studied by 10 collaborators. In the method, acid is added to the prepared amitrole sample, the solution is titrated potentiometrically with standard alkali, and the amitrole content is measured as the amount of alkali consumed between the first and second inflection points. Collaborative results on standard samples of a dry 90% formulation, a dry 50% formulation, and a liquid 2 lb/gallon formulation showed good agreement between samples and laboratories. Statistical analyses of the results were satisfactory, and the method for the assay of amitrole formulations is recommended for adoption as official, first action

The carbon isotopic composition of individual petroleum lipids

1984 ◽  
Vol 6 ◽  
pp. 665-670 ◽  
Author(s):  
I. Gilmour ◽  
P.K. Swart ◽  
C.T. Pillinger
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopic Composition ◽  
Carbon Isotopic
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