Measurement of the D/H, ¹⁸O/¹⁶O, and ¹⁷O/¹⁶O isotope ratios in water by laser absorption spectroscopy at 2.73 μm.
A compact isotope ratio laser spectrometry (IRLS) instrument was developed for simultaneous measurements of the D/H, 18O/16O and 17O/16O isotope ratios in water by laser absorption spectroscopy at 2.73 μm. Special attention is paid to the spectral data processing and implementation of a Kalman adaptive filtering to improve the measurement precision. Reduction of up to 3-fold in standard deviation in isotope ratio determination was obtained by the use of a Fourier filtering to remove undulation structure from spectrum baseline. Application of Kalman filtering enables isotope ratio measurement at 1 s time intervals with a precision (<1‰) better than that obtained by conventional 30 s averaging, while maintaining a fast system response. The implementation of the filter is described in detail and its effects on the accuracy and the precision of the isotope ratio measurements are investigated.
Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang 330063, China. wutccnu@nchu.edu.cn.
Tao
T
Wu
Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A, Av. Maurice Schumann, 59140 Dunkerque, France. chen@univ-littoral.fr.
Weidong
W
Chen
Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A, Av. Maurice Schumann, 59140 Dunkerque, France. eric.fertein@univ-littoral.fr.
Eric
E
Fertein
Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A, Av. Maurice Schumann, 59140 Dunkerque, France. pascal.masselin@univ-littoral.fr.
Pascal
P
Masselin
Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. xmgao@aiofm.ac.cn.
Xiaoming
X
Gao
Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. wjzhang@aiofm.ac.cn.
Weijun
W
Zhang
Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. wyj@aiofm.ac.cn.
Yingjian
Y
Wang
Nanoplus Nanosystems and Technologies GmbH, Oberer Kirschberg 4, 97218 Gerbrunn, Germany. johannes.koeth@nanoplus.com.
Johannes
J
Koeth
Nanoplus Nanosystems and Technologies GmbH, Oberer Kirschberg 4, 97218 Gerbrunn, Germany. daniela.brueckner@nanoplus.com.
Daniela
D
Brückner
Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang 330063, China. xdhe@126.com.
Xingdao
X
He
D000465:Algorithms; D003903:Deuterium / Q000032:analysis; D004867:Equipment Design; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D010103:Oxygen Isotopes / Q000032:analysis*; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000032:analysis* / Q000737:chemistry
D010103:Oxygen Isotopes; D014867:Water; D003903:Deuterium