1
|
Ohta T, Fukutani S, Kubota T, Mahara Y. Tritium concentration in the modern commercial D 2O reagents. ANAL SCI 2024:10.1007/s44211-024-00615-6. [PMID: 38862846 DOI: 10.1007/s44211-024-00615-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 06/01/2024] [Indexed: 06/13/2024]
Abstract
We investigated the tritium concentration in commercial modern D2O reagents frequently used in nuclear magnetic resonance analysis for analytical chemistry and in environmental tracer testing. The concentration of tritium in 11 D2O and 1 H218O reagents ranged from 61 Bq/L (5 × 102 TU) to 2.5 × 103 Bq/L (2 × 104 TU) in order of magnitude. The tritium concentration in the D2O reagents have increased with the increasing purity of D2O. The tritium concentration in all reagents was an order of magnitude greater than that in the surface waters at the Fukushima off-site of the Fukushima Daiichi Nuclear Power Plant after the accident in 2011 and in precipitation during the nuclear test era. However, the concentration of the tritium was lower than the regulatory limit for the concentration of tritium in drinking water accepted by the World Health Organization guidelines. The internal exposure effects from drinking the tritium water, which is contaminated by the tritium condensed in the reagent production processes, were negligible, even if the reagent was used in the environmental tracer test.
Collapse
Affiliation(s)
- Tomoko Ohta
- Department of Nuclear Technology, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan.
| | - Satoshi Fukutani
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Osaka, 590-0494, Japan
| | - Takumi Kubota
- Agency for Health, Safety and Environment, Kyoto University, Uji City, Kyoto, 611-0011, Japan
| | | |
Collapse
|
2
|
Ohta T, Fifield LK, Palcsu L, Tims SG, Pavetich S, Mahara Y. Record of 3H and 36Cl from the Fukushima nuclear accident recovered from soil water in the unsaturated zone at Koriyama. Sci Rep 2023; 13:19672. [PMID: 37952016 PMCID: PMC10640602 DOI: 10.1038/s41598-023-46853-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023] Open
Abstract
The opportunity to measure the concentrations of 3H and 36Cl released by the Fukushima nuclear accident in 2011 directly in rain was lost in the early stage of the accident. We have, however, been able to reconstruct the deposition record of atmospheric 3H and 36Cl following the accident using a bore hole that was drilled in 2014 at Koriyama at a distance of 60 km from the accident. The contributions of 3H and 36Cl from the accident are 1.4 × 1013 and 2.0 × 1012 atoms m-2 respectively at this site. Very high concentrations of both 3H (46 Bq L-1) and 36Cl (3.36 × 1011 atoms L-1) were found in the unsaturated soil at depths between 300 and 350 cm. From these, conservative estimates for the 3H and 36Cl concentrations in the precipitation in the ~ 6 weeks following the accident were 607 Bq L-1 and 4.74 × 1010 atoms L-1, respectively. A second hole drilled in 2016 showed that 3H concentrations in the unsaturated soil and shallow groundwater had returned to close to natural levels, although the 36Cl concentrations were still significantly elevated above natural levels.
Collapse
Affiliation(s)
- Tomoko Ohta
- Nagaoka University of Technology, Nagaoka, Japan.
- The University of Tokyo, Kashiwa, Japan.
| | | | - László Palcsu
- HUN-REN Institute for Nuclear Research, Debrecen, Hungary
| | | | | | | |
Collapse
|
3
|
Cui X, Li Y, Jiang C, Yuan Z, Zhou S, Chen W, Yu B. In situ measurement of water vapor isotope ratios in air with a laser-based spectrometer. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 283:121762. [PMID: 35985233 DOI: 10.1016/j.saa.2022.121762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/04/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Simultaneous measurement of H217O/H216O, H218O/H216O, and HDO/H216O in air with a compact spectrometer based on a mid-infrared distributed feedback (DFB) laser was described. The obtained mixing ratios of H216O, H217O, and H218O agreed reasonably well with those measured by a hygrometer. The precision and repeatability of the spectrometer were analyzed. Indoor air tests demonstrated that its 220-s precision was 0.08 ‰, 0.06 ‰, and 0.14 ‰ for δ18O, δ17O, and δ2H respectively. The measured values of δ18O, δ17O, and δ2H in indoor air were highly correlated with the water vapor mixing ratios. The compact spectrometer provides in situ measurements of water vapor isotopes with high precision and fast time response, which opens new possibilities for its application in atmospheric and hydrological research in the future.
Collapse
Affiliation(s)
- Xiaojuan Cui
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China.
| | - Yafan Li
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Chaochao Jiang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Zijian Yuan
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China
| | - Sheng Zhou
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Weidong Chen
- Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A Avenue, Maurice Schumann, 59140 Dunkerque, France
| | - Benli Yu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| |
Collapse
|
4
|
Xue X, Chu X, Zhang M, Wei F, Liang C, Liang J, Li J, Cheng W, Deng K, Liu W. High Hydrogen Isotope Separation Efficiency: Graphene or Catalyst? ACS APPLIED MATERIALS & INTERFACES 2022; 14:32360-32368. [PMID: 35792902 DOI: 10.1021/acsami.2c06394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Single-layer graphene has been demonstrated to be a high-efficiency hydrogen isotope sieving membrane in the electrochemical hydrogen pumping system. In this work, we transferred this membrane to proton exchange membrane water electrolysis (PEMWE), which has wide industrial applications. Two membrane electrode assemblies with decorated Pt and ink-coated Pt were investigated. The graphene with the decorated Pt scheme acquired the reported highest proton-to-tritium separation factor of 19.50 in PEMWE. However, rather than graphene, the decorated catalyst was demonstrated to be responsible for this remarkable separation efficiency. Previous studies from Geim's group underestimated the enhanced separation efficiency of decorated Pt over ink-coated Pt, resulting in an exaggerated separation efficiency for graphene. The behavior of proton transfer with hydrogen isotope separation through graphene was interpreted by a serial-parallel circuit model, which suggested that hydrogen isotope separation occurs at defect sites. The limited separation efficiency for graphene was also well understood by a density functional theory (DFT) calculation using an SW 55-77 model and the transition state theory for the kinetic isotope effect. This research provides a thorough understanding of proton transfer with hydrogen isotope separation through graphene.
Collapse
Affiliation(s)
- Xiaochong Xue
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - XinXin Chu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Mingjun Zhang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Wei
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chaofei Liang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Liang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinglin Li
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenyu Cheng
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke Deng
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Wei Liu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
5
|
Copia L, Wassenaar LI, Terzer-Wassmuth S, Belachew DL, Araguas-Araguas LJ. Comparative evaluation of 2H- versus 3H-based enrichment factor determination on the uncertainty and accuracy of low-level tritium analyses of environmental waters. Appl Radiat Isot 2021; 176:109850. [PMID: 34246163 DOI: 10.1016/j.apradiso.2021.109850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 05/26/2021] [Accepted: 06/28/2021] [Indexed: 10/21/2022]
Abstract
Analysis of low-level tritium (3H) in environmental waters requires pre-concentration using electrolytic enrichment prior to decay counting. Accurate and precise electrolytic enrichment factors (EF) are required to determine the sample's environmental 3H concentration. Two methods are used to determine EFs: i) the Spike Proxy Method (SPM) and ii) the Deuterium Method (DM) with each having several modalities. We conducted a comparative assessment of four EF strategies using 250 mL and 500 mL electrolytic enrichment of three low-level 3H proficiency water standards (0.5-7 TU) to see which strategy gave the most accurate 3H results based on z- and Zeta-scores. Our comparative evaluation revealed the DM offers consistently superior 3H results, with more precise EF determinations compared to the three SPM strategies. The DM gave the best z-scores with an EF relative combined uncertainty of about 0.5‰ and a negligible contribution to the overall uncertainty budget due to the EF determination. Moreover, the DM can improve productivity by eliminating the spike and gravimetric procedures from routine analyses and can give rapid cell enrichment performance feedback prior to decay counting. We recommend low-level tritium laboratories consider adopting the DM into their 3H sample enrichment and analysis operations.
Collapse
Affiliation(s)
- Lorenzo Copia
- International Atomic Energy Agency, Vienna International Center, A-1400, Vienna, Austria.
| | - Leonard I Wassenaar
- International Atomic Energy Agency, Vienna International Center, A-1400, Vienna, Austria
| | - Stefan Terzer-Wassmuth
- International Atomic Energy Agency, Vienna International Center, A-1400, Vienna, Austria
| | - Dagnachew L Belachew
- International Atomic Energy Agency, Vienna International Center, A-1400, Vienna, Austria
| | - Luis J Araguas-Araguas
- International Atomic Energy Agency, Vienna International Center, A-1400, Vienna, Austria
| |
Collapse
|
6
|
Lin YH, Wang YC, Wu MS, Lu KC, Lin HY, Kuo HS, Chang GD, Lin CM, Hsiao C. The study of isotopic enrichment of water in human plasma and erythrocyte. FASEB J 2020; 34:13049-13062. [PMID: 32779304 DOI: 10.1096/fj.202000388rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/11/2022]
Abstract
Life does not sustain without water. For water, there is a natural abundance of stable isotope hydrogen and oxygen. Water molecules get across cell membranes through a plasma membrane protein, named aquaporin. Moreover, the kidney is the main organ to maintain water homeostasis. Here, we study the stable isotopic ratios of hydrogen and oxygen in human blood plasma and erythrocyte corresponding to kidney functions. We extract waters from human plasma and erythrocyte, collected from 110 participants, including 51 clinically stable outpatients with end-stage renal disease (ESRD) and 59 subjects with normal renal function (NRF). We observed that (i) both extracellular (blood plasma) and intracellular (erythrocyte) biology waters are isotopic differences between the ESRD and NRF participants, (ii) the natural abundance of isotopic waters of ESRD is hypo-isotopic, and (iii) the isotopic enrichment of water between erythrocyte and blood plasma are distinct. In addition, we introduce an empirical formula using entropy transformation to describe isotopic water enrichment for biology. Accordingly, the natural abundance of stable isotope water of blood plasma and erythrocyte may be possibly put in practice a new sign for assessments of kidney dysfunctions.
Collapse
Affiliation(s)
- Yuan-Hau Lin
- College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ying-Chi Wang
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Mai-Szu Wu
- College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Nephrology, Taipei Medical University - Shuang Ho Hospital, New Taipei City, Taiwan
| | - Kuo-Cheng Lu
- School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hsin-Yi Lin
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsien-Shou Kuo
- College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Geen-Dong Chang
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Chun-Mao Lin
- College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chiaolong Hsiao
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
7
|
Gusyev MA, Morgenstern U, Nishihara T, Hayashi T, Akata N, Ichiyanagi K, Sugimoto A, Hasegawa A, Stewart MK. Evaluating anthropogenic and environmental tritium effects using precipitation and Hokkaido snowpack at selected coastal locations in Asia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 659:1307-1321. [PMID: 31096342 DOI: 10.1016/j.scitotenv.2018.12.342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/22/2018] [Accepted: 12/22/2018] [Indexed: 06/09/2023]
Abstract
Tritium dating requires a good understanding of the tritium and water inputs into hydrologic systems, including their main trends due to latitudinal, seasonal and altitudinal effects. Although tritium reached ambient levels at the end of the 20th century, tritium released from nuclear facilities and bomb tests since then has the potential to confound use of tritium for age dating. We therefore collected precipitation and snowpack samples for tritium analysis to confirm that tritium levels in Japanese precipitation had not exceeded ambient levels following the North Korean nuclear tests in January 6th 2016 and September 3rd 2017. As the result, the highest tritium concentration was 5.52(±0.27)TU at samples collected from January 8 to 11th at one Honshu and four Hokkaido locations and samples collected at six Honshu locations had 8.01(±1.5)TU from September 6 to 19th 2017. Confirming ambient tritium concentrations after both events we investigated the latitude tritium effect at selected coastal stations in Asia, indicating a break of latitude trend around Tokyo area, and established the latitude scaling factors to the north and south of the Tokyo area data. The seasonal trend was investigated during the winter-spring 2016 in precipitation samples confirming the higher spring tritium compared with winter continental tritium values. The altitude effect on tritium and stable (18O and 2H) isotopes was observed in Hokkaido snowpack, which had tritium concentrations ranging between 4.08 and 5.93 TU during March-April, and demonstrated two trends for western and central Hokkaido mountain ranges. Using established latitude and altitude scaling factors with the long-term continuous time-series of monthly Tokyo area tritium we estimated the annual weighted tritium at 110 meteorological stations in Japan with monthly precipitation demonstrating the applicability of this approach for future tritium-tracer studies across Asia.
Collapse
Affiliation(s)
- M A Gusyev
- International Centre for Water Hazard and Risk Management (ICHARM)/National Graduate Institute for Policy Studies (GRIPS), Public Works Research Institute (PWRI), Tsukuba 305-8516, Japan.
| | | | - T Nishihara
- Civil Engineering Research Institute for Cold Region (CERI), PWRI, Sapporo 062-8602, Japan
| | - T Hayashi
- Akita University, Akita 010-8502, Japan
| | - N Akata
- National Institute for Fusion Science (NIFS), Toki 509-5292, Japan
| | | | - A Sugimoto
- Hokkaido University, Sapporo 060-0808, Japan
| | | | | |
Collapse
|
8
|
A laboratory information management system for the analysis of tritium ( 3 H) in environmental waters. Appl Radiat Isot 2018; 137:139-146. [DOI: 10.1016/j.apradiso.2018.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/16/2018] [Accepted: 03/06/2018] [Indexed: 11/21/2022]
|
9
|
Wassenaar LI, Han LF, Schiefer T, Kainz G, Araguas-Araguas L, Aggarwal PK. A simple polymer electrolyte membrane system for enrichment of low-level tritium ( 3H) in environmental water samples. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2018; 54:274-287. [PMID: 29166773 DOI: 10.1080/10256016.2017.1403914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/08/2017] [Indexed: 06/07/2023]
Abstract
Tritium (3H) is an essential tracer of the Earth's water cycle; yet widespread adoption of tritium in hydrologic studies remains a challenge because of analytical barriers to quantification and detection of 3H by electrolytic pre-concentration. Here, we propose a simple tritium electrolytic enrichment system based on the use of solid polymer electrolyte membranes (PEMs) that can be used to enrich 3H in 250-3000 mL environmental water samples to a 10-mL final volume. The IAEA PEM-3H system reported here can produce high enrichment factors (>70-fold) and, importantly, removes some of the deterrents to conventional 3H enrichments methods, including the use of toxic electrolysis and neutralization chemicals, spike standards, a complex electrolysis apparatus that requires extensive cooling and temperature controls, and improves precision by eliminating the need for tracking recovery gravimetrics. Preliminary results with varying operating conditions show 3H enrichments to 70-fold and higher are feasible, spanning a wide range of tritium activities from 5 to 150 TU with a precision of ∼4.5 %. Further work is needed to quantify inter-sample memory and to establish lower 3H detection limits. The IAEA PEM-3H system is open source, with 3-D CAD and design files made freely available for adoption and improvement by others.
Collapse
Affiliation(s)
- Leonard I Wassenaar
- a Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Center , Vienna , Austria
| | - Liang-Feng Han
- a Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Center , Vienna , Austria
| | | | - Gustav Kainz
- a Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Center , Vienna , Austria
| | - Luis Araguas-Araguas
- a Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Center , Vienna , Austria
| | - Pradeep K Aggarwal
- a Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Center , Vienna , Austria
| |
Collapse
|
10
|
Kumar B, Han LF, Wassenaar L, Klaus P, Kainz G, Hillegonds D, Brummer D, Ahmad M, Belachew D, Araguás L, Aggarwal P. A compact tritium enrichment unit for large sample volumes with automated re-filling and higher enrichment factor. Appl Radiat Isot 2016; 118:80-86. [DOI: 10.1016/j.apradiso.2016.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 07/06/2016] [Accepted: 07/19/2016] [Indexed: 11/15/2022]
|
11
|
Schauer AJ, Schoenemann SW, Steig EJ. Routine high-precision analysis of triple water-isotope ratios using cavity ring-down spectroscopy. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:2059-2069. [PMID: 27469283 DOI: 10.1002/rcm.7682] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/13/2016] [Accepted: 07/08/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Water isotope analysis for δ(2) H and δ(18) O values via laser spectroscopy is routine for many laboratories. While recent work has added the δ(17) O value to the high-precision suite, it does not follow that researchers will routinely obtain high precision (17) O excess (Δ(17) O). We demonstrate the routine acquisition of high-precision δ(2) H, δ(17) O, δ(18) O, d, and Δ(17) O values using a commercially available laser spectroscopy instrument. METHODS We use a Picarro L2140-i cavity ring-down spectroscopy analyzer with discrete liquid injections into an A0211 vaporization module by a Leap Technologies LC PAL autosampler. The instrument is run in two modes: (1) as recommended by the manufacturer (default mode) and (2) after modifying select default settings and using alternative data types (advanced mode). Reference waters analyzed over the course of 15 months while running unknown samples are used to assess system performance. RESULTS The default mode provides precision for δ(2) H, δ(17) O, δ(18) O, d, and Δ(17) O values that may be sufficient for many applications. When using the advanced mode, we reach a higher level of precision for δ(2) H, δ(17) O, δ(18) O, d, and Δ(17) O values (0.4 mUr, 0.04 mUr, 0.07 mUr, 0.5 mUr, and 8 μUr, respectively, where mUr = 0.001 = ‰, and μUr = 10(-6) ) in a shorter amount of time and with fewer syringe actuations than in the default mode. The improved performance results from an increase in the total integration time for each injected water pulse. CONCLUSIONS Our recommended approach for routine δ(2) H, δ(17) O, δ(18) O, d and Δ(17) O measurements with the Picarro L2140-i is to make use of conditioning vials, use fewer injections (5 per vial) with greater pulse duration (520 seconds (s) per injection) and use only the first 120 s for δ(2) H measurements and all 520 s for δ(17) O and δ(18) O measurements. Although the sample throughput is 10 unknowns per day, our optimal approach reduces the number of syringe actuations, the effect of memory, and the total analysis time, while improving precision relative to the default approach. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Andrew J Schauer
- IsoLab, Department of Earth and Space Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Spruce W Schoenemann
- IsoLab, Department of Earth and Space Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Eric J Steig
- IsoLab, Department of Earth and Space Sciences, University of Washington, Seattle, WA, 98195, USA
| |
Collapse
|