A new concept for sensitive in situ stable isotope ratio infrared spectroscopy based on sample modulation
Authors: Werle P., Dyroff C., Zahn A., Mazzinghi P., D’Amato F.
Autors Affiliation: CNR – Istituto Nazionale di Ottica Applicata, Largo E. Fermi 6, Firenze, Italy;
Institute for Meteorology and climate Research, Research Center Karlsruhe, Germany
Abstract: Diode-laser absorption spectroscopy finds increasing applications in the emerging field of stable isotope research. To meet the requirements of the water isotopes measurement challenge in environmental research, ways have to be found to cope with the present limitations of spectroscopic systems. In this article, we discuss an approach based on the Stark effect in molecular spectra to reduce the influence of time-dependent, unwanted background structures generally superimposed on the desired signal from the spectral feature under investigation. A road map to high-sensitivity isotopic ratio measurements of water isotopes is presented. On the basis of an Allan Variance analysis of measured data, the detection limits have been calculated as a function of the integration time. To achieve the required optical density of about 6 x 10(-7) for (H2O)-O-17 measurements, the duty cycle has to be optimized and the implementation of a sample modulation within an optical multipass cell is a promising approach to increase the stability of spectroscopic instrumentation required for ecosystem research and airborne atmospheric platforms.
Journal/Review: ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES
Volume: 41 (4) Pages from: 323 to: 333
KeyWords: Diode-laser spectroscopy; Hydrogen-2; Isotope analysis; Stark effect; DOI: 10.1080/10256010500384366Citations: 7data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-07-05References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here