Trace metal speciation measurements in waters by the liquid binding phase DGT device.
The speciation measurements of trace metals by the diffusive gradients in thin-films technique (DGT) using a poly(4-styrenesulfonate) (PSS) aqueous solution as a binding phase and a cellulose dialysis membrane (CDM) as a diffusive layer, CDM-PSS DGT, were investigated and showed good agreement with computer modelling calculations. The diffusion coefficients of ethylenediaminetetraacetic acid (EDTA) complexes with Cd(2+) and Cu(2+) were measured and compared with those of the inorganic metal ions. CDM-PSS DGT device was tested for speciation measurement in sample solutions containing EDTA, tannic acid (TA), glucose (GL), dodecylbenzenesulfonic acid (DBS) and humic acid (HA) as complexing ligands forming organic complexes with varying stability constants. Lower percentages of DGT labile copper concentrations over total filterable copper concentrations obtained from the deployments in freshwater sites indicated that copper complexes with organic matter were basically not measured by the devices.
Li
Weijia
W
School of Environmental and Applied Sciences, Gold Coast Campus, Griffith University, PMB 50, Gold Coast Mail Centre, Qld 9726, Australia; Environmental Science Program and Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Zhao
Huijun
H
Teasdale
Peter R
PR
Wang
Feiyue
F