Assessment of the performance of diffusive gradients in thin-films for metal contaminant measurements in Antarctic marine waters

This study assessed the performance of diffusive gradients in thin-films (DGT) with a binding resin that used Chelex-100 (iminodiacetic acid functional groups) to measure cadmium, copper, nickel, lead, and zinc contaminants in Antarctic marine conditions. To do this, three sets of experiments were done: (I) the uptake of metals to DGT samplers was assessed over time when deployed to three metal mixtures of known concentrations (DGT performance page). This allowed for the determination of metal diffusion coefficients in Antarctic marine conditions and demonstrated when metal competition for binding sites were likely to occur. (II) the DGT were deployed in the presence of the microalga Phaeocystis antarctica at a concentration of 1000-3000 cells/mL to investigate how environmentally realistic concentrations of an Antarctic marine microalgae affect the uptake of metals (DGT uptake with algae page). Finally, the DGT-labile concentrations from part (II) were used in reference toxicity mixture models to predict toxicity to the microalgae so they could be compared to a previous study that investigated the toxicity of metal mixtures to Phaeocystis antarctica and Cryothecomonas armigera (DGT toxicity modelling page).