TY - JOUR
T1 - Influence of salinity and dissolved organic carbon on acute Cu toxicity to the rotifer Brachionus plicatilis
AU - Cooper, Christopher A.
AU - Tait, Tara
AU - Gray, Holly
AU - Cimprich, Giselle
AU - Santore, Robert C.
AU - McGeer, James C.
AU - Wood, Christopher M.
AU - Smith, D. Scott
PY - 2014/1/21
Y1 - 2014/1/21
N2 - Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼1.1, ∼3.1, ∼4.9, ∼13.6 mg C L-1) on Cu bioavailability. Total Cu was measured using anodic stripping voltammetry, and free Cu2+ was measured using ion-selective electrodes. There was a protective effect of salinity observed in all but the highest DOC concentrations; at all other DOC concentrations the LC50 value was significantly higher at 30 ppt than at 3 ppt. At all salinities, DOC complexation significantly reduced Cu toxicity. At higher concentrations of DOC the protective effect increased, but the increase was less than expected from a linear extrapolation of the trend observed at lower concentrations, and the deviation from linearity was greatest at the highest salinity. Light-scattering data indicated that salt induced colloid formation of DOC could be occurring under these conditions, thereby decreasing the number of available reactive sites to complex Cu. When measurements of free Cu across DOC concentrations at each individual salinity were compared, values were very similar, even though the total Cu LC50 values and DOC concentrations varied considerably. Furthermore, measured free Cu values and predicted model values were comparable, highlighting the important link between the concentration of bioavailable free Cu and Cu toxicity.
AB - Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼1.1, ∼3.1, ∼4.9, ∼13.6 mg C L-1) on Cu bioavailability. Total Cu was measured using anodic stripping voltammetry, and free Cu2+ was measured using ion-selective electrodes. There was a protective effect of salinity observed in all but the highest DOC concentrations; at all other DOC concentrations the LC50 value was significantly higher at 30 ppt than at 3 ppt. At all salinities, DOC complexation significantly reduced Cu toxicity. At higher concentrations of DOC the protective effect increased, but the increase was less than expected from a linear extrapolation of the trend observed at lower concentrations, and the deviation from linearity was greatest at the highest salinity. Light-scattering data indicated that salt induced colloid formation of DOC could be occurring under these conditions, thereby decreasing the number of available reactive sites to complex Cu. When measurements of free Cu across DOC concentrations at each individual salinity were compared, values were very similar, even though the total Cu LC50 values and DOC concentrations varied considerably. Furthermore, measured free Cu values and predicted model values were comparable, highlighting the important link between the concentration of bioavailable free Cu and Cu toxicity.
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U2 - 10.1021/es402186w
DO - 10.1021/es402186w
M3 - Article
C2 - 24380586
AN - SCOPUS:84892712067
VL - 48
SP - 1213
EP - 1221
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 2
ER -