Solid phase extracted (SPE) metal distributions collected on the US GEOTRACES GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023

Molecular speciation affects the solubility, bioavailability, toxicity, scavenging and regeneration rates, and water column residence times of trace elements in the ocean. The molecular speciation of trace elements is what microbes "sense" and respond to. Here, we report the molecular speciation of iron and iodine in water samples collected as part of the US GEOTRACES GP17 expedition from Tahiti to Punta Areanas, Chile. Dissolved organic matter in filtered seawater was recovered by solid phase extraction onto hydrophobic resins, and recovered with organic solvent. Trace element organic complexes were characterized and quantified by liquid chromatography coupled to inductively coupled mass spectrometry.