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).

本研究评估了搭载Chelex-100（亚氨基二乙酸功能基团）螯合树脂的薄膜扩散梯度技术（diffusive gradients in thin-films, DGT）的性能，用于检测南极海洋环境中的镉、铜、镍、铅、锌污染物。为此共开展三组实验：(I) 将DGT采样器部署于三种已知浓度的金属混合液中，随时间评估金属的吸附量（DGT performance page）。该实验可测定南极海洋环境中的金属扩散系数，并阐明金属结合位点竞争的潜在发生时机。(II) 将DGT置于浓度为1000~3000个细胞/毫升的南极海洋微藻*Phaeocystis antarctica*环境中，以探究环境现实浓度的南极海洋微藻对金属吸附过程的影响（DGT uptake with algae page）。最后，将(II)中得到的DGT有效态浓度代入参考毒性混合模型，以预测该微藻的受毒程度，并可与此前一项探究金属混合物对*Phaeocystis antarctica*和*Cryothecomonas armigera*毒性的研究进行对比（DGT toxicity modelling page）。