Elvira Pulido (MIO)
Malcolm Woodward (PML, UK)
The Mediterranean Sea is an oligotrophic area where the quantification of phosphate is a challenging task because concentrations drop to nanomolar levels, therefor unquantifiable using conventional techniques. The MIO laboratory is now using a nanomolar method for phosphate measurements (LWCC) and a new data set of phosphate concentration in Mediterranean surface waters was acquired, shedding new light on the behavior of phosphate in surface waters at both the seasonal and the spatial scale (cf AIOLOS project).
However, the LWCC analysis of nanomolar concentrations of DIP is currently a manual technique. The main objective of this project is to make it automatic in order to gain sensitivity, precision and efficiency. For this purpose, three main tasks were proposed:
1) Acquisition of a new LWCC system
2) Invitation to the MIO of Malcolm Woodward for knowledge transfer
3) Validation of the implemented LWCC-SCFA system to low phosphate Mediterranean waters.
1) A new LWCC system was acquired.
2) It was coupled with an already existing segmented continuous flow autoanalyser (SCFA) system.
3) Malcolm Woodward (PML, UK), a referent in the automated analysis of phosphate using the LWCC-SCFA coupled technique, visited MIO to train staff.
The developed methods and skills were operational at MIO by the end of 2018. The acquired expertise has already contributed to research activities in the Mediterranean Sea through the PERLE project (MISTRALS-MERMEX), for which the the NanoP-Med team determines nanomolar phosphate concentrations. Part of the team participated in the PERLE-2 cruise between February and March 2019, transfering the new analytical setup onboard the research vessel.
An unprecedented dataset of nanomolar concentrations of phosphate was obtained, a key element for Mediterranean biogeochemistry.
Nanomolar concentration of phosphate (DIP, nM) in surface waters (0-200 m) of the Mediterranean Sea along a longitudinal transect south of Crete (Elvira Pulido, unpublished data).