Organic complexation of copper in throughfall and open field bulk
deposition: Influence of the tree canopy of Mediterranean forest
ecosystems
Sotirios Karavoltsos
a, *
, Fotios Fotiadis
a
, Panagiotis Michopoulos
b
, Aikaterini Sakellari
a
,
Marta Plav
si
c
c
, Athanassios Bourletsikas
b
, Kostas Kaoukis
b
, Nikolaos S. Thomaidis
d
,
Manos Dassenakis
a
, Michael Scoullos
a
a
National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Environmental Chemistry, Panepistimiopolis,157 84, Athens,
Greece
b
H.A.O. DEMETER, Institute of Mediterranean Forest Ecosystems, Terma Alkmanos, 115 28 Athens, Greece
c
RuCer Bo skovi c Institute, Center for Marine and Environmental Research, P.O. Box 180,10002 Zagreb, Croatia
d
National and Kapodistrian University of Athens, Department of Chemistry, Laboratory of Analytical Chemistry, Panepistimiopolis,157 84, Athens, Greece
highlights graphical abstract
Cu complexation in forest throughfall
was studied for the first time by
DPASV.
Samples were collected from two
different Mediterranean forest
ecosystems.
In throughfall (TF) and bulk deposi-
tion (BD) copper was fully
complexed.
Cu ligands concentrations were
determined 3e4 fold higher in TF
than in BD.
HULIS seem to be the most wide-
spread type of ligands in both type of
precipitations.
article info
Article history:
Received 21 April 2016
Received in revised form
16 September 2016
Accepted 26 September 2016
Available online 2 October 2016
Handling Editor: Martine Leermakers
Keywords:
Throughfall
Bulk deposition
Copper complexing capacity
Apparent stability constant
Canopy
abstract
The complexing capacity for Cu ions (L
T
) and the apparent stability constant values (logK
app
) were
measured in throughfall (TF) and open field bulk deposition (BD), at two Mediterranean forest ecosys-
tems of western Greece. L
T
was measured for the first time in the TF of natural forests.
Concentrations of L
T
were three-to-four-fold higher in TF (mean ± st.dev: 2014 ± 769 nM for Varetada
and 1565 ± 595 nM for Karpenissi) compared to those in BD (531 ± 517 nM and 468 ± 321 nM,
respectively). In all TF and BD samples, L
T
concentrations were significantly higher than the corre-
sponding total Cu concentrations, indicating that Cu was fully complexed. The L
T
/TOC ratios in TF were
found comparable between the two study sites (235 ± 149 nM mg
1
C for Varetada and
256 ± 233 nM mg
1
C for Karpenissi) and with those of BD (226 ± 257 and 163 ± 163 nM mg
1
C,
respectively). The determined mean logK
app
values were almost identical in TF (6.8 ± 0.7 at Varetada;
6.8 ± 0.6 at Karpenissi) and BD (6.5 ± 0.6 at Varetada; 6.8 ± 0.3 at Karpenissi), pointing to the fact that
regardless of the enrichment of TF in ligands (L
T(TF)
> L
T(BD)
) the type of binding sites remain the same.
* Corresponding author.
E-mail address: skarav@chem.uoa.gr (S. Karavoltsos).
Contents lists available at ScienceDirect
Chemosphere
journal homepage: www.elsevier.com/locate/chemosphere
http://dx.doi.org/10.1016/j.chemosphere.2016.09.131
0045-6535/© 2016 Elsevier Ltd. All rights reserved.
Chemosphere 167 (2017) 28e35