Study of perfomance reference compounds for the estimation of levels of emerging polar contaminants in water

The determination of polar organic contaminants (pesticides, pharmaceuticals and inhibitors of corrosion) in river water was carried out using POCIS as a passive sampling technique and UPLC-MS/MS as a determination technique. Several compounds with properties similar to studied pollutants were evaluated as potential PRCs. Only DIA-d5 and 5-Methylbenzotriazol-d3 (5-TT-d3) were linearly released from HLB sorbent. As far as we know, 5-TT-d3 was used as PRC for the first time in POCIS. Both compounds could correct the effect of water velocity in the estimation of Cw. To confirm the suitable correction of Rs by proposed PRCs, further researches are needed under different environmental conditions.

Investigation of pollution sources in rivers using passive sampling: a discussion based on in-situ experiments on PCBs

Luiz Felippe De Alencastro, Nicolas Estoppey, Julien Omlin

Tools able to investigate pollution sources at low cost are urgently needed to achieve the requirements of the Water Frame Directive and international treaties (such as the Stockholm Convention) which are to reduce, or even cease, pollution emissions to water and other parts of the environment. Based on in-situ experiments on PCBs, this study assesses the use of passive sampling as a tool to investigate point sources of hydrophobic pollutants in rivers. The proposed methodology deploys passive samplers downstream and upstream potential pollution sources (or even in their outlets) and considers that increases of aqueous concentration between sites may reveal the presence of pollution sources. The authors present data obtained from investigations carried out with low density polyethylene (LDPE) strips in the Venoge River (Switzerland) which is known to be polluted by PCBs (ou alors where fishes are known to be polluted by PCBs). Results are discussed taking into account, firstly, the variations of exposure conditions among sites (hydrodynamics, temperature and biofouling) which can cause different concentrations in samplers for equal contamination levels and, secondly, the fact that the uptake of pollutants having reached equilibrium is no more influenced by exposure conditions. It turns out that passive sampling offers a simple interpretation when equilibrium is reached and/or exposure conditions are similar since concentration in samplers can directly be compared among sites. When equilibrium is not reached and exposure conditions differ among sites, the release rate constants are necessary to calculate and compare aqueous concentrations. The efficiency of performance reference compounds (PRCs) to determine which compounds haven’t reached equilibrium and approximate their release rate constant is evaluated with in-situ experiments which are also presented here.

2013

Passive sampling for monitoring organic contaminants in aquatic systems

Sylvain Coudret, Luiz Felippe De Alencastro, Nicolas Estoppey, Dominique Grandjean, Adrien Schopfer

Passive sampling has been shown to be a good alternative to grab sampling. Because of the in-situ accumulation in samplers, limits of quantitation are low enough to measure organic pollutants in water. In addition, integrative passive samplers enable to sequester pollutants from episodic pollution and provide time weighted average (TWA) concentrations. Finally, they do not require a power supply in the field and are flexible enough to be deployed at sites that are difficult to access. This study will present the interest and efficiency of passive sampling to reveal industrial and agricultural pollution trends. Two practical applications for nonpolar and polar contaminants are presented. Low-density polyethylene (LDPE) and Silicon rubber (SR) samplers were deployed in rivers to monitor indicator PCBs (iPCBs, IUPAC nos. 28, 52, 101, 138, 153 and 180). The results showed that the impact of PCBs emissions into the river is higher in summer than other seasons due to the low flow rate of the river during the summer period. Polar organic chemical integrative samplers (POCIS) were deployed in another river to investigate herbicides coming from vineyards. The results showed an increase of water contamination due to the studied agricultural area. The maximal contamination was observed in April and corresponds to the period of herbicide application on the crops. The use of performance reference compounds (PRCs) to estimate aqueous concentrations is also presented and illustrated by examples.

2017

Investigation of pollution sources in rivers using passive sampling: a discussion based on in-situ experiments on PCBs

Luiz Felippe De Alencastro, Nicolas Estoppey, Julien Omlin

2013