Determination of iron in seawater: From the laboratory to in situ measurements

The marine biogeochemistry of iron plays a significant role in regulating climate change. Trace dissolved iron in oceanic surface water can limit phytoplankton growth which in turn limits the carbon dioxide flux at the air/sea interface. To better understand the relationship between iron and its different species with phytoplankton, as well as the biogeochemical cycle of iron in seawater, accurate, sensitive, and in situ methods are needed for iron determination. This paper reviews the methods for determining iron in seawater from the laboratory, shipboard to in situ measurements, including such strategies as atomic spectrometry, spectrophotometry, chemiluminescence, and voltammetry, which will provide the foundation for developing reliable long-term iron monitoring and sensing platforms in the future.