A new concept for sensitive in situ stable isotope ratio infrared spectroscopy based on sample modulation.
Isotopes Environ Health Stud
; 41(4): 323-33, 2005 Dec.
Article
en En
| MEDLINE
| ID: mdl-16543188
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 H(2)(17)O 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.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Isótopos de Oxígeno
/
Espectrofotometría Infrarroja
/
Agua
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Isotopes Environ Health Stud
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2005
Tipo del documento:
Article
País de afiliación:
Italia