Tf. Rozan et G. Benoit, Intercomparison of DPASV and ISE for the measurement of Cu complexation characteristics of NOM in freshwater, ENV SCI TEC, 33(10), 1999, pp. 1766-1770
Citations number
20
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Complexation by dissolved humic substances has an important influence on tr
ace metal behavior in-natural systems. Unfortunately,few analytical techniq
ues are available with adequate sensitivity and selectivity to measure free
metal ions reliably at the low concentrations under which they occur in na
tural waters. In the past, differential pulse anodic Stripping voltammetry
with a thin mercury film rotating disk glassy carbon electrode (DPASV-TMF-R
DGCE)has been used to measure complexation capacities and conditional, meta
l-ligand binding constants in oceanic and estuarine waters. In contrast, fe
w studies have been conducted to validate DPASV's use in freshwaters. The c
urrent study compares DPASV and Cu ion-selective electrode (CulSE)methods f
or measuring free copper, complexation capacities, and conditional binding
constants on samples of synthetic and isolated natural organics. Titration
data show that DPASV and CulSE are able to measure similar:amounts of labil
e copper when the two methods' detection windows overlap. Furthermore, the
greater sensitivity of DPASV allows it to measure free copper at lower conc
entrations, which correlated well with CulSE data extrapolated into that sa
me region. This strong correlation between these analytical methods provide
s positive evidence for the use of DPASV (TMF-RDGCE) in measuring free Cu2, complexation capacities, and conditional binding constants in freshwaters
.