Our research involves the study of the metabolic budget of the ocean and different chemical oceanographic parameters. For this work, we collaborate with the Analytical Core Lab of KAUST.
Winkler iodometric determination is a reference method for the measurement of dissolved oxygen (DO) in waters. This methodology allows the determination of Gross Primary Production (GPP), Net Community Production (NCP) and Community Respiration (CR) produced by the plankton community. Community Respiration and NCP are calculated from changes in DO concentrations, before and after incubation of samples in dark and transparent conditions respectively. GPP is calculated as NCP + CDO. DO concentrations are determined by automated high-precision titration. Measurements are performed with a Mettler Toledo Autotritator M 50 (using calibrated potentiometric electrodes and automated end-point detection). With these methods, we achieve an estimate of the variation and biogeography of the pelagic community. It allows for fully automated high-precision titration, required for oxygen analyses and alkalinity measurements. The Mettler Toledo instrument can handle more than 8 samples in a carrousel sampling system, allowing for fast throughput of samples.
This is an important parameter for understanding the carbonate system in sea water. It is a parameter that can be combined with additional parameters, e.g., pH, CO2, or dissolved inorganic carbon (DIC), to determine other parameters. Alkalinity measurements could be done with two titrator systems: