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Interview with Professor Hao Zhang, Lancaster University, UK, and member of the MONITOOL scientific advisory board
Designing and development of an additional experiment performed by IFREMER at the laboratory
AZTI presents MONITOOL results at different scientific events during 2020
Instituto Tecnológico de Canarias (ITC) carried out a wastewater sampling campaign following the MONITOOL standardized methods
DCU Masters student, Martin Nolan, submits his MSc Thesis based on MONITOOL acquired knowledge
Evaluation of the impact of biofouling on deployments of DGT
COVID-19 impact on MONITOOL project implementation
MONITOOL Partners take part in the annual ICES expert’s meetings
Technical conference on passive samplers and MONITOOL project takes place in the Basque Country
Interview with Isabelle Amouroux, leader of MONITOOL Work Package 6 (EQS Adaptation and Chemical Status Assessment)
MONITOOL partners share and assess the results in Nantes and proceed with the last steps of the project
Interview with Maria J. Belzunce Ph.D., leader of MONITOOL Work Package 4 (Database Management and correlation studies)
IPMA complete metal analysis in seawater samples
UNICA (University of Cagliari) organized a conference the 20 June 2019 in Cagliari
MONITOOL Data Quality Assurance: a holistic view
DGT Conference 2019 will be the fifth international scientific event with MONITOOL presence in 2019
MONITOOL partners share results and plan next steps in Gran Canaria
Technical conferences present MONITOOL project and DGT passive sampling in the Canary Islands
Interview with Thi Bolam, leader of MONITOOL Work Package 5
ITC will organize 2 technical conferences in the days preceding the next partners´ meeting in Canary Islands
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DGT extraction and metal analysis by IFREMER

DGT extraction and metal analysis by IFREMER

The DGT technique is used to extract and concentrate metal cations in situ. Their use has shown that this approach is applicable for many metallic elements (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn).

DGT resine recovery

Photo: DGT resine recovery – april 2018

DGT are very simple devices to implement. They irreversibly accumulate (on a Chelex 100 resin) the most "labile" dissolved metal cations (hydrated ions, mineral complexes, small organic complexes) depending on their concentration in the medium and the immersion time. The device consists of a plastic support, on which are arranged successively a phase for which the metal cations have a very strong affinity (Chelex 100 resin), a diffusion hydrogel of known thickness and a protective polycarbonate filter (Fig. 1&2). The metal cations migrate through the diffusion gel and settle irreversibly on the resin. It is the diffusion, controlled by the physical properties of the gel, temperature and metal concentration in the medium to be sampled, that determines the accumulation kinetics on the resin.

Diffusion of metal cations 

Figure 1: Photo of a DGT and operating principle

After recovery, the resin from each DGT is removed and eluted with nitric acid (1M). The eluate is analyzed by ICP-MS to determine the mass (M) of the various metallic elements accumulated in the resin.

Following the wet sampling campaign, most Monitool partners sent their DGT to Ifremer in April 2018. More than 150 DGTs were processed a few days after receipt (photo), then eluates were sent for ICP-MS analysis.

Cross section view of a DGT

Figure 2: Cross-section view of a DGT (the proportions are not respected)