Precise Measurements of 12CH2D2 by Tunable Infrared Laser Direct Absorption Spectroscopy

Yenny Gonzalez; David D. Nelson; Joanne H. Shorter; J. Barry McManus; Christoph Dyroff; Michael Formolo; David T. Wang; Colin M. Western; Shuhei Ono

doi:10.1021/acs.analchem.9b03412

Precise Measurements of ¹²CH₂D₂ by Tunable Infrared Laser Direct Absorption Spectroscopy

Yenny Gonzalez, David D. Nelson, Joanne H. Shorter, J. Barry McManus, Christoph Dyroff, Michael Formolo, David T. Wang, Colin M. Western, Shuhei Ono^*

^*Corresponding author for this work

Research output: Contribution to journal › Article (Academic Journal) › peer-review

17 Citations (Scopus)

109 Downloads (Pure)

Abstract

We present precise measurements of doubly deuterated methane (¹²CH₂D₂) in natural methane samples using tunable infrared laser direct absorption spectroscopy (TILDAS). Using a 413 m optical path length astigmatic Herriott cell and two quantum cascade lasers (QCLs) scanning the spectral regions of 1090.46 ± 0.1 and 1200.23 ± 0.1 cm^-1, the instrument simultaneously measures the five main isotopologues of methane. The ratios ¹³CH₃D/¹²CH₄ and ¹²CH₂D₂/¹²CH₄ are measured at 0.01‰ and 0.5‰ (1σ) instrumental precision, respectively. The instrumental accuracy was assessed by measuring a series of methane gases with a range of δ¹³C and δD values but with the abundances of all isotopologues driven to thermal equilibrium at 250 °C. The estimated accuracy of Δ¹²CH₂D₂ is 1‰ (1σ) on the basis of the results of the heated methane samples. This new TILDAS instrument provides a simple and rapid technique to explore the sources of methane in the environment.

Original language	English
Article number	23
Pages (from-to)	14967-14974
Number of pages	8
Journal	Analytical Chemistry
Volume	91
DOIs	https://doi.org/10.1021/acs.analchem.9b03412
Publication status	Published - 30 Oct 2019

Access to Document

10.1021/acs.analchem.9b03412

Full-text PDF (accepted author manuscript)
This is the author accepted manuscript (AAM). The final published version (version of record) is available online via American Chemical Society at https://pubs.acs.org/doi/10.1021/acs.analchem.9b03412#. Please refer to any applicable terms of use of the publisher.
Accepted author manuscript, 955 KB

Handle.net

Persistent link

Cite this

@article{8c9a78c844cb42b68980a3ce6a6db7b7,

title = "Precise Measurements of 12CH2D2 by Tunable Infrared Laser Direct Absorption Spectroscopy",

abstract = "We present precise measurements of doubly deuterated methane (12CH2D2) in natural methane samples using tunable infrared laser direct absorption spectroscopy (TILDAS). Using a 413 m optical path length astigmatic Herriott cell and two quantum cascade lasers (QCLs) scanning the spectral regions of 1090.46 ± 0.1 and 1200.23 ± 0.1 cm-1, the instrument simultaneously measures the five main isotopologues of methane. The ratios 13CH3D/12CH4 and 12CH2D2/12CH4 are measured at 0.01‰ and 0.5‰ (1σ) instrumental precision, respectively. The instrumental accuracy was assessed by measuring a series of methane gases with a range of δ13C and δD values but with the abundances of all isotopologues driven to thermal equilibrium at 250 °C. The estimated accuracy of Δ12CH2D2 is 1‰ (1σ) on the basis of the results of the heated methane samples. This new TILDAS instrument provides a simple and rapid technique to explore the sources of methane in the environment.",

author = "Yenny Gonzalez and Nelson, {David D.} and Shorter, {Joanne H.} and McManus, {J. Barry} and Christoph Dyroff and Michael Formolo and Wang, {David T.} and Western, {Colin M.} and Shuhei Ono",

year = "2019",

month = oct,

day = "30",

doi = "10.1021/acs.analchem.9b03412",

language = "English",

volume = "91",

pages = "14967--14974",

journal = "Analytical Chemistry",

issn = "0003-2700",

publisher = "American Chemical Society",

}

TY - JOUR

T1 - Precise Measurements of 12CH2D2 by Tunable Infrared Laser Direct Absorption Spectroscopy

AU - Gonzalez, Yenny

AU - Nelson, David D.

AU - Shorter, Joanne H.

AU - McManus, J. Barry

AU - Dyroff, Christoph

AU - Formolo, Michael

AU - Wang, David T.

AU - Western, Colin M.

AU - Ono, Shuhei

PY - 2019/10/30

Y1 - 2019/10/30

N2 - We present precise measurements of doubly deuterated methane (12CH2D2) in natural methane samples using tunable infrared laser direct absorption spectroscopy (TILDAS). Using a 413 m optical path length astigmatic Herriott cell and two quantum cascade lasers (QCLs) scanning the spectral regions of 1090.46 ± 0.1 and 1200.23 ± 0.1 cm-1, the instrument simultaneously measures the five main isotopologues of methane. The ratios 13CH3D/12CH4 and 12CH2D2/12CH4 are measured at 0.01‰ and 0.5‰ (1σ) instrumental precision, respectively. The instrumental accuracy was assessed by measuring a series of methane gases with a range of δ13C and δD values but with the abundances of all isotopologues driven to thermal equilibrium at 250 °C. The estimated accuracy of Δ12CH2D2 is 1‰ (1σ) on the basis of the results of the heated methane samples. This new TILDAS instrument provides a simple and rapid technique to explore the sources of methane in the environment.

AB - We present precise measurements of doubly deuterated methane (12CH2D2) in natural methane samples using tunable infrared laser direct absorption spectroscopy (TILDAS). Using a 413 m optical path length astigmatic Herriott cell and two quantum cascade lasers (QCLs) scanning the spectral regions of 1090.46 ± 0.1 and 1200.23 ± 0.1 cm-1, the instrument simultaneously measures the five main isotopologues of methane. The ratios 13CH3D/12CH4 and 12CH2D2/12CH4 are measured at 0.01‰ and 0.5‰ (1σ) instrumental precision, respectively. The instrumental accuracy was assessed by measuring a series of methane gases with a range of δ13C and δD values but with the abundances of all isotopologues driven to thermal equilibrium at 250 °C. The estimated accuracy of Δ12CH2D2 is 1‰ (1σ) on the basis of the results of the heated methane samples. This new TILDAS instrument provides a simple and rapid technique to explore the sources of methane in the environment.

UR - http://www.scopus.com/inward/record.url?scp=85075155190&partnerID=8YFLogxK

U2 - 10.1021/acs.analchem.9b03412

DO - 10.1021/acs.analchem.9b03412

M3 - Article (Academic Journal)

C2 - 31663335

VL - 91

SP - 14967

EP - 14974

JO - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

M1 - 23

ER -

Precise Measurements of ¹²CH₂D₂ by Tunable Infrared Laser Direct Absorption Spectroscopy

Abstract

Access to Document

Handle.net

Other files and links

Fingerprint

Dr Colin M Western

Cite this

Precise Measurements of 12CH2D2 by Tunable Infrared Laser Direct Absorption Spectroscopy

Abstract

Access to Document

Handle.net

Other files and links

Fingerprint

Profiles

Dr Colin M Western

Cite this

Precise Measurements of ¹²CH₂D₂ by Tunable Infrared Laser Direct Absorption Spectroscopy