3.5 Cr(III) samples
Dissolved chromium redox speciation (Cr(III)) samples were processed at
sea using magnesium hydroxide (Mg(OH)2)
co-precipitation, then analysed by isotope dilution ICP-MS on land at
the University of Bern following the procedures of Janssen et al. (2020)
(external [Cr(III)] 1σ = 10% RSD, Janssen et al., 2020).