The lab-on-chip (LOC) iron sensor is a miniaturised wet chemical analyser capable of in situ measurements of iron (II) and iron (III).

The system uses the ferrozine assay, and is based on the same hardware platform as the LOC nitrate and phosphate sensors. Like all instruments based on this platform, the iron analyser is designed to work at full ocean pressure. The iron analyser can also be adapted to perform manganese II analysis using the PAN method. The range is 0.027 to 500µM; LOD is 0.027µM.

Early prototypes of the LOC Fe sensor were successfully deployed in rivers and on CTD profiles in the Baltic. The platform has recently been re-engineered in line with the nitrate and phosphate sensors to improve robustness and reliability, and has since been successfully deployed in glacial meltwater streams in the Peruvian Andes as part of the CASCADA project. This version of the sensor is cable of measuring Iron II and Iron III with a pre-acidification step.

Geißler, F., Achterberg, E.P., Beaton, A.D., Hopwood, M.J., Clarke, J.S., Mutzberg, A., Mowlem, M.C., Connelly, D.P. (2017) Evaluation of a Ferrozine Based Autonomous in Situ Lab-on-Chip Analyzer for Dissolved Iron Species in Coastal Waters. Front. Mar. Sci., 4. https://doi.org/10.3389/fmars.2017.00322.