A novel flow-based procedure for automation of respirometric assays in soils.
Talanta
; 158: 14-20, 2016 Sep 01.
Article
en En
| MEDLINE
| ID: mdl-27343572
ABSTRACT
A flow-based strategy involving a gas-diffusion sampling probe was proposed for evaluating the respiration rate in soils. The amount of CO2 collected after a pre-defined time interval was proportional to the free CO2 released by the soil ecosystem. The 500-mL incubation flasks typically used for soil respirometric assays were adapted and a special cover was designed for connecting a tubular gas diffusion membrane, a fan, and a septum for adding the CO2(g) standards required for calibration. The method relied on the pH-dependent absorbance variations resulting from the CO2 collection. A 1.3mmolL(-1) bromothymol blue solution (pH 7.0) acted as both acceptor and carrier streams. In order to widen the dynamical working range to 0.003-0.2mmol CO2, two analytical curves were obtained, each related to a different time interval for the CO2 collection. Kinetic curves related to CO2 release by the soil samples were straightforwardly attained. Repeatability and detection limit were estimated as 2.0% and 0.001mmol CO2 (n=10), and accuracy was assessed in relation to a recommended titrimetric procedure.
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Base de datos:
MEDLINE
Asunto principal:
Microbiología del Suelo
/
Dióxido de Carbono
Idioma:
En
Revista:
Talanta
Año:
2016
Tipo del documento:
Article