%0 Journal Article 
%A Mendiguchía Martínez, Carolina
%A Vergel Rodríguez, Cristina
%A Moreno Aguilar, Carlos
%T Coupled Extraction/Re-Extraction Method for the Chemical Speciation of Nickel in NaturalWaters
%D 2020
%@ 2076-3417
%U http://hdl.handle.net/10498/22519
%X Chemical fractionation and speciation of metals species in natural waters and its relation
with bioavailability have received increased attention in recent years. A simple liquid membranes
method, based on coupled liquid extraction and re-extraction processes, is proposed to separate and
quantify the species of nickel present in water samples. A simplex optimization of chemical variables,
such as carrier concentration in the organic solution and nitric acid concentration in the receiving
solution, was performed and, under optimized conditions, the extraction system was applied to
determine nickel species in water samples at natural level concentrations. A linear relationship
was established between extraction e cacy and the concentration of dissolved organic carbon in
the samples, allowing the separation and determination of labile and non-labile nickel fractions,
since the latter was not transported through the organic solution acting as liquid membrane. When the
total and labile concentrations of metals were analyzed in real samples with di erent salinities,
no significant di erences were found between the results obtained and those from well-established
methods. An average relative error of 1.50 and 2.37 was obtained for total Ni concentration and
labile fraction, respectively. Finally, a comparison with the theoretical speciation data calculated
with the softwareWinHumic V was successfully performed. Thus, the proposed method allows the
simultaneous determination of labile and non-labile nickel fractions, presented as a simple alternative
to nickel fractionation in natural waters.
%K natural waters
%K extraction
%K re-extraction
%K liquid membrane
%K metals
%K nickel
%K speciation
%K fractionation
%K labile
%K non-labile
%~ Universidad de Cádiz