Improved in situ Li isotopic ratio analysis of silicates by optimizing signal intensity, isotopic ratio stability and intensity matching using ns-LA-MC-ICP-MS

2017 ◽  
Vol 32 (4) ◽  
pp. 834-842 ◽  
Author(s):  
Jie Lin ◽  
Yongsheng Liu ◽  
Xirun Tong ◽  
Lvyun Zhu ◽  
Wen Zhang ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Isotopic Ratio ◽  
Silicate Glasses ◽  
Isotopic Ratios ◽  
Ratio Analysis ◽  
Icp Ms

How to get accurate and precise in situ Li isotopic ratios of silicate glasses on a ns-LA-MC-ICP-MS (Neptune Plus).

scholarly journals Calibration and field testing of cavity ring-down laser spectrometers measuring CH<sub>4</sub>, CO<sub>2</sub>, and <i>δ</i><sup>13</sup>CH<sub>4</sub> deployed on towers in the Marcellus Shale region

2018 ◽  
Vol 11 (3) ◽  
pp. 1273-1295 ◽  
Author(s):  
Natasha L. Miles ◽  
Douglas K. Martins ◽  
Scott J. Richardson ◽  
Christopher W. Rella ◽  
Caleb Arata ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Natural Gas ◽  
Mole Fraction ◽  
Isotopic Ratio ◽  
Marcellus Shale ◽  
Isotopic Ratios ◽  
Study Region ◽  
Wide Range ◽  
Cavity Ring Down

Abstract. Four in situ cavity ring-down spectrometers (G2132-i, Picarro, Inc.) measuring methane dry mole fraction (CH4), carbon dioxide dry mole fraction (CO2), and the isotopic ratio of methane (δ13CH4) were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications and characterize their performance in the field for the period January–December 2016. Prior to deployment, each analyzer was tested using bottles with various isotopic ratios, from biogenic to thermogenic source values, which were diluted to varying degrees in zero air, and an initial calibration was performed. Furthermore, at each tower location, three field tanks were employed, from ambient to high mole fractions, with various isotopic ratios. Two of these tanks were used to adjust the calibration of the analyzers on a daily basis. We also corrected for the cross-interference from ethane on the isotopic ratio of methane. Using an independent field tank for evaluation, the standard deviation of 4 h means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field tank testing scheme, the standard deviation of 4 h means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round-robin style testing using tanks with near-ambient isotopic ratios indicated mean errors of −0.14 to 0.03 ‰ for each of the analyzers. Flask to in situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the east and south towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median differences of the isotopic ratio measured at three of the towers, compared to the background tower, were &amp;minus0.15 to 0.12 ‰ with standard deviations of the 10 min isotopic ratio differences of 0.8 ‰. In terms of source attribution, analyzer compatibility of 0.2 ‰ δ13CH4 affords the ability to distinguish a 50 ppb CH4 peak from a biogenic source (at −60 ‰, for example) from one originating from a thermogenic source (−35 ‰), with the exact value dependent upon the source isotopic ratios. Using a Keeling plot approach for the non-afternoon data at a tower in the center of the study region, we determined the source isotopic signature to be −31.2 ± 1.9 ‰, within the wide range of values consistent with a deep-layer Marcellus natural gas source.

scholarly journals Using ship-borne observations of methane isotopic ratio in the Arctic Ocean to understand methane sources in the Arctic

2019 ◽  
Author(s):  
Antoine Berchet ◽  
Isabelle Pison ◽  
Patrick M. Crill ◽  
Brett Thornton ◽  
Philippe Bousquet ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Large Scale ◽  
Transport Model ◽  
Isotopic Ratio ◽  
The Arctic ◽  
Isotopic Ratios ◽  
Air Masses ◽  
Remote Areas ◽  
The Arctic Ocean

Abstract. Due to the large variety and heterogeneity of sources in remote areas hard to document, the Arctic regional methane budget remain very uncertain. In situ campaigns provide valuable data sets to reduce these uncertainties. Here we analyse data from the SWERUS-C3 campaign, on-board the icebreaker Oden, that took place during summer 2014 in the Arctic Ocean along the Northern Siberian and Alaskan shores. Total concentrations of methane, as well as isotopic ratios were measured continuously during this campaign for 35 days in July and August 2014. Using a chemistry-transport model, we link observed concentrations and isotopic ratios to regional emissions and hemispheric transport structures. A simple inversion system helped constraining source signatures from wetlands in Siberia and Alaska and oceanic sources, as well as the isotopic composition of lower stratosphere air masses. The variation in the signature of low stratosphere air masses, due to strongly fractionating chemical reactions in the stratosphere, was suggested to explain a large share of the observed variability in isotopic ratios. These points at required efforts to better simulate large scale transport and chemistry patterns to use isotopic data in remote areas. It is found that constant and homogeneous source signatures for each type of emission in the region (mostly wetlands and oil and gas industry) is not compatible with the strong synoptic isotopic signal observed in the Arctic. A regional gradient in source signatures is highlighted between Siberian and Alaskan wetlands, the later ones having a lighter signatures than the first ones. Arctic continental shelf sources are suggested to be a mixture of methane from a dominant thermogenic origin and a secondary biogenic one, consistent with previous in-situ isotopic analysis of seepage along the Siberian shores.

Determination of Zr isotopic ratios in zircons using laser-ablation multiple-collector inductively coupled-plasma mass-spectrometry

2019 ◽  
Vol 34 (9) ◽  
pp. 1800-1809 ◽  
Author(s):  
Wen Zhang ◽  
Zaicong Wang ◽  
Frédéric Moynier ◽  
Edward Inglis ◽  
Shengyu Tian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Isotopic Ratios ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Isotope Variation

An in situ Zr isotopic analytical method for zircons was developed using LA-MC-ICP-MS to reveal the Zr stable isotope variation in the complex mineral crystallization history.

U-Pb dating, oxygen and hafnium isotopic ratios of zircon from rocks of oceanic core complexes at Mid-Atlantic Ridge: evidence for an interaction of young and ancient crusts at spreading of the ocean floor

2019 ◽  
Vol 489 (5) ◽  
pp. 483-489
Author(s):  
N. S. Bortnikov ◽  
S. А. Silantiev ◽  
F. Bea ◽  
P. Montero ◽  
T. F. Zinger ◽  
...  
Keyword(s):  
Continental Crust ◽  
Oceanic Crust ◽  
Isotopic Ratio ◽  
Ocean Floor ◽  
Isotopic Ratios ◽  
Icp Ms ◽  
Different Ages ◽  
Mid Atlantic Ridge ◽  
Slow Spreading ◽  
Central Atlantic

U-Pb age, oxygen and hafnium isotopic ratios in zircon from rocks of ocean core complexes at Mid-Atlantic Ridge have been studied using SHRIMP and MC-LA-ICP-MS techniques. U-Pb dating revealed four group of zircons: 1) 0,6-1,7 Ma, 2) 6,7-11,2 Ma, 3) 12,9-17,6 Ma, 4) 200 to 2044 Ma. The 18O values range from 4,74 to 7,2 and are distinct for zircon grains of different ages. Hafnium isotopic ratio for zircon aged from 0,6 to 17,6 Ma corresponds or is close to that of MORB from Central Atlantic. The oxygen and hafnium isotopic compositions of zircon elder than 280 Ma correspond to those of the sialic continental crust. A hypothesis of involvement of the ancient pre-Atlantic sialic (280 млн лет) and old Atlantic (7-17 Ma) crusts in a generation of the contemporary (young) oceanic crust during formation of the slow-spreading Mid-Atlantic Ridge has been proposed.

scholarly journals Combined U-Pb and Lu-Hf isotope analyses by laser ablation MC-ICP-MS: methodology and applications

2010 ◽  
Vol 82 (2) ◽  
pp. 479-491 ◽  
Author(s):  
Massimo Matteini ◽  
Elton L. Dantas ◽  
Marcio M. Pimentel ◽  
Bernhard Bühn
Keyword(s):  
Isotopic Ratio ◽  
Sediment Provenance ◽  
Significant Information ◽  
Icp Ms ◽  
Borborema Province ◽  
Isotopic Studies ◽  
The University ◽  
Isotope Analyses ◽  
Magmatic Event

The Lutetium-Hafnium isotopic system represents one of the most innovative and powerful tools for geochronology and isotopic studies. Combined U-Pb and Lu-Hf in situ analyses on zircon by LA-MC-ICP-MS permit to characterize isotopically the host magma from which it crystallized furnishing significant information for sediment provenance and crustal evolution studies. In this paper e describe the Lu-Hf systematic by LA-MC-ICP-MS developed in the laboratory of Geochronology of the University of Brasilia and report the results obtained by repeated analyses of 176Hf/177Hf isotopic ratio of three zircon standards: GJ-1 = 0.282022 ± 11 (n=56), Temora 2 = 0.282693 ± 14 (n=25) and UQZ = 0.282127 ± 33 (n=11). The 176Hf/177Hf ratio (0.282352 ± 22, n=14) of gem quality zircon used as in-house standard have been also characterized. As a geological application, we analyzed two complex zircons selected from a migmatitic rocks from the Borborema Province, NE Brazil. On the basis of U-Pb and Lu-Hf data, two main crystallization events have been identified in both studied zircons. An older event at ca. 2.05 Ga recognized in the inherited cores represents a well-characterized paleoproterozoic magmatic event that affected the whole Borborema Province. A second crystallization event at ~ 575 Ma, recognized at the rims, represents a Neoproterozoic (Brazilian) high grade metamorphic-magmatic event.

scholarly journals Calibration and Field Testing of Cavity Ring-Down Laser Spectrometers Measuring CH<sub>4</sub>, CO<sub>2</sub>, and δ<sup>13</sup>CH<sub>4</sub> Deployed on Towers in the Marcellus Shale Region

2017 ◽  
Author(s):  
Natasha L. Miles ◽  
Douglas K. Martins ◽  
Scott J. Richardson ◽  
Christopher W. Rella ◽  
Caleb Arata ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Natural Gas ◽  
Mole Fraction ◽  
Isotopic Ratio ◽  
Marcellus Shale ◽  
Isotopic Ratios ◽  
Study Region ◽  
Field Calibration ◽  
Cavity Ring Down

Abstract. Four in-situ cavity ring-down spectrometers (G2132-i, Picarro, Inc.) measuring methane dry mole fraction (CH4), carbon dioxide dry mole fraction (CO2) and the isotopic ratio of methane (δ13CH4) were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. The calibration of the continuous isotopic methane analyzers used in this study required both a linear calibration and a mole fraction correction, and a correction for cross-interference from ethane. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications, and characterize their performance in the field for the period January–December 2016. Prior to deployment, each analyzer was calibrated using high methane mole fraction air bottles with various isotopic ratios, from biogenic to thermogenic source values, diluted in zero air. Furthermore, at each tower location, three field calibration tanks were employed, from ambient to high mole fractions, with various isotopic ratios. By testing multiple calibration schemes, we determined an optimized field calibration method. A method to correct for cross interference from ethane is also described. Using an independent field tank for evaluation, the standard deviation of 4-hour means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field calibration tank sampling scheme, the standard deviation of 4-hour means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round robin style testing using tanks with near ambient isotopic ratios indicated mean errors of −0.14 to 0.03 ‰ for each of the analyzers. Flask to in-situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the East and South towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median enhancements of isotopic ratio measured at three of the towers, compared to the background tower, were −0.15 to 0.12 ‰ with standard deviations of the 10-min isotopic ratio enhancements of 0.8 ‰. In terms of source attribution, analyzer compatibility of 0.2 ‰ δ13CH4 affords the ability to distinguish a 50 ppb CH4 peak from a biogenic source from one originating from a thermogenic source. Using a Keeling plot approach for the non-afternoon data at a tower in the center of the study region, we determined the source isotopic signature to be −31.2 ‰, consistent with a deep-layer Marcellus natural gas source.

scholarly journals A new set of standards for in – situ measurement of bromine abundances in natural silicate glasses: Application to SR-XRF, LA-ICP-MS and SIMS techniques

2017 ◽  
Vol 452 ◽  
pp. 60-70 ◽  
Author(s):  
Anita Cadoux ◽  
Giada Iacono-Marziano ◽  
Antonio Paonita ◽  
Etienne Deloule ◽  
Alessandro Aiuppa ◽  
...  
Keyword(s):  
In Situ Measurement ◽  
Silicate Glasses ◽  
Sr Xrf ◽  
Icp Ms ◽  
Natural Silicate

In Situ Analysis of Non-Traditional Isotopes by SIMS and LA–MC–ICP–MS: Key Aspects and the Example of Mg Isotopes in Olivines and Silicate Glasses

2017 ◽  
Vol 82 (1) ◽  
pp. 127-163 ◽  
Author(s):  
Marc Chaussidon ◽  
Zhengbin Deng ◽  
Johan Villeneuve ◽  
Julien Moureau ◽  
Bruce Watson ◽  
...  
Keyword(s):  
Silicate Glasses ◽  
In Situ Analysis ◽  
Icp Ms ◽  
Mg Isotopes ◽  
Key Aspects

In situ high-precision lithium isotope analyses at low concentration levels with femtosecond-LA-MC-ICP-MS

2019 ◽  
Vol 34 (7) ◽  
pp. 1447-1458 ◽  
Author(s):  
Lena K. Steinmann ◽  
Martin Oeser ◽  
Ingo Horn ◽  
Hans-Michael Seitz ◽  
Stefan Weyer
Keyword(s):  
High Precision ◽  
Signal Intensity ◽  
Lithium Isotope ◽  
Single Measurement ◽  
Low Concentration ◽  
Icp Ms ◽  
Isotope Analyses ◽  
Concentration Levels

Precision of a single measurement in the low signal intensity area is better with a combination of a 1013 Ω amplifier and a SEM.

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