Influence of natural organic matter source on copper speciation as demonstrated by Cu binding to fish gills, by ion selective electrode, and by DGT gel sampler.
Rainbow trout (Oncorhynchus mykiss, 2 g) were exposed to 0-5 microM total copper in ion-poor water for 3 h in the presence or absence of 10 mg C/L of qualitatively different natural organic matter (NOM) derived from water spanning a large gradient in hydrologic residence time. Accumulation of Cu by trout gills was compared to Cu speciation determined by ion selective electrode (ISE) and by diffusive gradients in thin films (DGT) gel sampler technology. The presence of NOM decreased Cu uptake by trout gills as well as Cu concentrations determined by ISE and DGT. Furthermore, the source of NOM influenced Cu binding by trout gills with high-color, allochthonous NOM decreasing Cu accumulation by the gills more than low-color autochthonous NOM. The pattern of Cu binding to the NOM measured by Cu ISE and by Cu accumulation by DGT samplers was similar to the fish gill results. A simple Cu-gill binding model required an NOM Cu-binding factor (F) that depended on NOM quality to account for observed Cu accumulation by trout gills; values of Fvaried by a factor of 2. Thus, NOM metal-binding quality, as well as NOM quantity, are both important when assessing the bioavailability of metals such as Cu to aquatic organisms.
Luider
Chad D
CD
Earth and Environmental Science Department, Okanagan University College, Kelowna, British Columbia, Canada V1V 1V7.
Crusius
John
J
Playle
Richard C
RC
Curtis
P Jeff
PJ
D000818:Animals; D001682:Biological Availability; D018533:Biomass; D003300:Copper / Q000737:chemistry* / Q000493:pharmacokinetics*; D004058:Diffusion; D005618:Fresh Water / Q000737:chemistry; D005880:Gills / Q000378:metabolism; D017736:Ion-Selective Electrodes; D008954:Models, Biological; D017686:Oncorhynchus mykiss / Q000378:metabolism*
D003300:Copper