Fully automated, high‐throughput instrumentation for measuring the δ<sup>13</sup>C value of methane and application of the instrumentation to rice paddy samples

Tokida, Takeshi; Nakajima, Yasuhiro; Hayashi, Kentaro; Usui, Yasuhiro; Katayanagi, Nobuko; Kajiura, Masako; Nakamura, Hirofumi; Hasegawa, Toshihiro

doi:10.1002/rcm.7016

Cited by 19 publications

(12 citation statements)

References 56 publications

(127 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For this GC/C/IRMS at the CER, the precision of repeated analysis was ±0.19‰ when 44 nmol of CH 4 was injected. For low CH 4 concentration samples, δ 13 C‐CH 4 was determined using GC/C/IRMS (Delta V advantage, Thermo Fisher Scientific) with a cryofocus trap at the National Institute for Agro‐Environmental Sciences (NIAES), Japan [ Tokida et al , ]. For this GC/C/IRMS at the NIAES, the precision of repeated analysis was ±0.11‰ when 1.6 nmol of CH 4 was injected.…”

Section: Methodsmentioning

confidence: 99%

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir

et al. 2015

Self Cite

View full text Add to dashboard Cite

Although freshwaters are considered to be substantial natural sources of atmospheric methane (CH 4 ), in situ processes of CH 4 production and consumption in freshwater ecosystems are poorly understood, especially in subtropical areas, leading to uncertainties in the estimation of global CH 4 emissions. To improve our understanding of physical and biogeochemical factors affecting CH 4 dynamics in subtropical lakes, we examined vertical and seasonal profiles of dissolved CH 4 and its carbon isotope ratio (δ 13 C) and conducted incubation experiments to assess CH 4 production and oxidation in the deep subtropical Fei-Tsui Reservoir (FTR; Taiwan). The mixing pattern of the FTR is essentially monomixis, but the intensity of winter vertical mixing changes with climatic conditions. In years with incomplete vertical mixing (does not reach the bottom) and subsequent strong thermal stratification resulting in profundal hypoxia, we observed increases in sedimentary CH 4 production and thus profundal CH 4 storage with the development of reducing conditions. In contrast, in years with strong winter vertical mixing to the bottom of the reservoir, CH 4 production was suppressed under NO 3 À -rich conditions, during which denitrifiers have the competitive advantage over methanogens. Diffusive emission from profundal CH 4 storage appeared to be negligible due to the efficiency of CH 4 oxidation during ascent through methane-oxidizing bacteria (MOB) activity. Most of the profundal CH 4 was rapidly oxidized by MOB in both oxic and anoxic layers, as characterized by its carbon isotope signature. In contrast, aerobic CH 4 production in the subsurface layer, which may be enhanced under high temperatures in summer, may account for a large portion of atmospheric CH 4 emissions from this reservoir. Our CH 4 profiling results provide valuable information for future studies predicting CH 4 emissions from subtropical lakes with the progress of global warming.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Craig, 1953;Schiegl and Vogel, 1970) to recent publications on analytical systems to measure isotope ratios in atmospheric CH 4 (e.g. Sapart et al, 2011;Sperlich et al, 2013;Bock et al, 2014;Tokida et al, 2014;Eyer et al, 2015) as well as papers that present and interpret such data (e.g. Levin et al, 2012;Sapart et al, 2013;Schaefer et al, 2016).…”

Section: Introductionmentioning

confidence: 93%

Development and evaluation of a suite of isotope reference gases for methane in air

et al. 2016

View full text Add to dashboard Cite

Abstract. Measurements from multiple laboratories have to be related to unifying and traceable reference material in order to be comparable. However, such fundamental reference materials are not available for isotope ratios in atmospheric methane, which led to misinterpretations of combined data sets in the past. We developed a method to produce a suite of synthetic CH4-in-air standard gases that can be used to unify methane isotope ratio measurements of laboratories in the atmospheric monitoring community. Therefore, we calibrated a suite of pure methane gases of different methanogenic origin against international referencing materials that define the VSMOW (Vienna Standard Mean Ocean Water) and VPDB (Vienna Pee Dee Belemnite) isotope scales. The isotope ratios of our pure methane gases range between −320 and +40 ‰ for δ2H–CH4 and between −70 and −40 ‰ for δ13C–CH4, enveloping the isotope ratios of tropospheric methane (about −85 and −47 ‰ for δ2H–CH4 and δ13C–CH4 respectively). Estimated uncertainties, including the full traceability chain, are < 1.5 ‰ and < 0.2 ‰ for δ2H and δ13C calibrations respectively. Aliquots of the calibrated pure methane gases have been diluted with methane-free air to atmospheric methane levels and filled into 5 L glass flasks. The synthetic CH4-in-air standards comprise atmospheric oxygen/nitrogen ratios as well as argon, krypton and nitrous oxide mole fractions to prevent gas-specific measurement artefacts. The resulting synthetic CH4-in-air standards are referred to as JRAS-M16 (Jena Reference Air Set – Methane 2016) and will be available to the atmospheric monitoring community. JRAS-M16 may be used as unifying isotope scale anchor for isotope ratio measurements in atmospheric methane, so that data sets can be merged into a consistent global data frame.

show abstract

Section: Introductionmentioning

confidence: 93%

author's response

Sperlich¹

2016

View full text Add to dashboard Cite

Measurements from multiple laboratories have to be related to unifying and traceable reference material in order to be comparable. However, such fundamental reference materials are not available for isotope ratios in atmospheric methane, which led to misinterpretations of combined data sets in the past. We developed a method to produce a suite of synthetic CH 4 -in-air standard gases that can be used to unify methane isotope ratio measurements of laboratories in the atmospheric monitoring community. Therefore, we calibrated a suite of pure methane gases of different methanogenic origin against international referencing materials that define the VSMOW (Vienna Standard Mean Ocean Water) and VPDB (Vienna Pee Dee Belemnite) isotope scales. The isotope ratios of our pure methane gases range between −320 and +40 ‰ for δ 2 H-CH 4 and between −70 and −40 ‰ for δ 13 C-CH 4 , enveloping the isotope ratios of tropospheric methane (about −85 and −47 ‰ for δ 2 H-CH 4 and δ 13 C-CH 4 respectively). Estimated uncertainties, including the full traceability chain, are < 1.5 ‰ and < 0.2 ‰ for δ 2 H and δ 13 C calibrations respectively. Aliquots of the calibrated pure methane gases have been diluted with methane-free air to atmospheric methane levels and filled into 5 L glass flasks. The synthetic CH 4 -in-air standards comprise atmospheric oxygen/nitrogen ratios as well as argon, krypton and nitrous oxide mole fractions to prevent gasspecific measurement artefacts. The resulting synthetic CH 4in-air standards are referred to as JRAS-M16 (Jena Reference Air Set -Methane 2016) and will be available to the atmospheric monitoring community. JRAS-M16 may be used as unifying isotope scale anchor for isotope ratio measurements in atmospheric methane, so that data sets can be merged into a consistent global data frame.

show abstract

Fully automated, high‐throughput instrumentation for measuring the δ¹³C value of methane and application of the instrumentation to rice paddy samples

Cited by 19 publications

References 56 publications

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir

Development and evaluation of a suite of isotope reference gases for methane in air

author's response

Contact Info

Product

Resources

About

Fully automated, high‐throughput instrumentation for measuring the δ13C value of methane and application of the instrumentation to rice paddy samples

Cited by 19 publications

References 56 publications

Effect of interannual variation in winter vertical mixing on CH4 dynamics in a subtropical reservoir

Effect of interannual variation in winter vertical mixing on CH4 dynamics in a subtropical reservoir

Development and evaluation of a suite of isotope reference gases for methane in air

author's response

Contact Info

Product

Resources

About

Fully automated, high‐throughput instrumentation for measuring the δ¹³C value of methane and application of the instrumentation to rice paddy samples

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir

Effect of interannual variation in winter vertical mixing on CH₄ dynamics in a subtropical reservoir