TY - JOUR
T1 - Assessing variability in the ratio of metal concentrations measured by DGT-type passive samplers and spot sampling in European seawaters
AU - Rodríguez, José Germán
AU - Amouroux , Isabelle
AU - Belzunce-Segarra, María Jesús
AU - Bersuder, Philippe
AU - Bolam, Thi
AU - Caetano, Miguel
AU - Carvalho, Inês
AU - dos Santos, Margarida Correia
AU - Fones, Gary
AU - Gonzalez, Jean-Louis
AU - Guesdon, Stephane
AU - Larreta, Joana
AU - Marras, Barbara
AU - McHugh, Brendan
AU - Menet-Nédélec, Florence
AU - Menchaca, Iratxe
AU - Millán Gabet , Vanessa
AU - Montero, Natalia
AU - Nolan, Martin
AU - Regan, Fiona
AU - Robinson, Craig D.
AU - Rosa, Nuno
AU - Sanz, Marta Rodrigo
AU - Schintu, Marco
AU - White, Blánaid
AU - Zhang, Hao
PY - 2021/8/20
Y1 - 2021/8/20
N2 - The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks.
AB - The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks.
KW - EU Water Framework Directive
KW - Diffusive Gradients in thin-films (DGT)
KW - Passive samplers
U2 - 10.1016/j.scitotenv.2021.147001
DO - 10.1016/j.scitotenv.2021.147001
M3 - Article
SN - 0048-9697
VL - 783
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 147001
ER -