NORMAN interlaboratory study (ILS) on passive sampling of emerging pollutants

A chemical monitoring on site (CM Onsite) organised by NORMAN Association and JRC in support of the Water Framework Directive

Passive samplers can play a valuable role in monitoring water quality within a legislative framework such as the European Union’s Water Framework Directive (WFD). The time-integrated data from these devices can be used to complement chemical monitoring of priority and emerging contaminants which are difficult to analyse by spot or bottle sampling methods, and to improve risk assessment of chemical pollution. In order to increase the acceptance of passive sampling technology amongst end users and to gain further information about the robustness of the calibration and analytical steps, several inter-laboratory field studies have recently been performed in Europe. Such trials are essential to further validate this sampling method and to increase the confidence of the technological approach for end users. An inter-laboratory study on the use of passive samplers for the monitoring of emerging pollutants was organised in 2011 by the NORMAN association (Network of reference laboratories for monitoring emerging environmental pollutants; http://www.norman-network.net) together with the European DG Joint Research Centre to support the Common Implementation Strategy of the WFD. Thirty academic, commercial and regulatory laboratories participated in the passive sampler comparison exercise and each was allowed to select their own sampler design. All the different devices were exposed at a single sampling site to treated waste water from a large municipal treatment plant. In addition, the organisers deployed in parallel for each target analyte class multiple samplers of a single type which were subsequently distributed to the participants for analysis. This allowed an evaluation of the contribution of the different analytical laboratory procedures to the data variability. The results obtained allow an evaluation of the potential of different passive sampling methods for monitoring selected emerging organic contaminants (pharmaceuticals, polar pesticides, steroid hormones, fluorinated surfactants, triclosan, bisphenol A and brominated flame retardants). In most cases, between laboratory variation of results from passive samplers was roughly a factor 5 larger than within laboratory variability. Similar results obtained for different passive samplers analysed by individual laboratories and also low within laboratory variability of sampler analysis indicate that the passive sampling process is causing less variability than the analysis. This points at difficulties that laboratories experienced with analysis in complex environmental matrices. Where a direct comparison was possible (not in case of brominated flame retardants) analysis of composite water samples provided results that were within the concentration range obtained by passive samplers. However, in the future a significant improvement of the overall precision of passive sampling is needed. The results will be used to inform EU Member States about the potential application of passive sampling methods for monitoring organic chemicals within the framework of the WFD. (2016)

The report

Fast identification of microplastics in complex environmental samples by a thermal degradation method

In order to determine the relevance of microplastic particles in various environmental media, comprehensive investigations are needed. However, no analytical method exists for fast identification and quantification. At present, optical spectroscopy methods like IR and RAMAN imaging are used. Due to their time consuming procedures and uncertain extrapolation, reliable monitoring is difficult. For analyzing polymers Py-GC-MS is a standard method. However, due to a limited sample amount of about 0.5 mg it is not suited for analysis of complex sample mixtures like environmental samples. Therefore, we developed a new thermoanalytical method as a first step for identifying microplastics in environmental samples. A sample amount of about 20 mg, which assures the homogeneity of the sample, is subjected to complete thermal decomposition. The specific degradation products of the respective polymer are adsorbed on a solid-phase adsorber and subsequently analyzed by thermal desorption gas chromatography mass spectrometry. For certain identification, the specific degradation products for the respective polymer were selected first. Afterwards real environmental samples from the aquatic (three different rivers) and the terrestrial (bio gas plant) systems were screened for microplastics. Mainly polypropylene (PP), polyethylene (PE) and polystyrene (PS) were identified for the samples from the bio gas plant and PE and PS from the rivers. However, this was only the first step and quantification measurements will follow.

Erik Dümichen, , Paul Eisentraut, Claus Gerhard Bannick and al., Chemosphere, Volume 174, May 2017, Pages 572–584

The article

Detection of phthalate esters in seawater by stir bar sorptive extraction and gas chromatography–mass spectrometry

We developed the stir bar sorptive extraction (SBSE)–gas chromatography–mass spectrometry (GC–MS) method to detect 15 kinds of PAEs in seawater. The stir bars (20 mm in length and 1 mm in film thickness) coated with 150 μL of polydimethylsiloxane (PDMS) were found to demonstrate the optimal extraction of PAEs. The optimal conditions were as follows: extraction time of 2 h, extraction temperature of 25 °C, sodium chloride of 5%, methanol of 10%, analytical time of 50 min, and methanol–acetonitrile (4:1) as the solvent. SBSE–GC–MS revealed that under the set temperature, the chromatographic peaks of all 15 PAEs can appear with complete separation. The detection limit ranged from 0.07 μg/L to 5.71 μg/L, whereas the limit of quantification ranged from 0.023 μg/L to 193 μg/L, and the correlation coefficients between the chromatographic peak area and concentration of the PAEs were greater than 0.92.

Qingqing Si, Fengmin Li, Chenchen Gao, Cong Wang, Zhenyu Wang, Jian Zhao, Marine Pollution Bulletin, Volume 108, Issues 1–2, 15 July 2016, Pages 163–170

The article

A Procedure for Measuring Microplastics using Pressurized Fluid Extraction

A method based on Pressurized Fluid Extraction (PFE) was developed for measuring microplastics in environmental samples. This method can address some limitations of the current microplastic methods and provide laboratories with a simple analytical method for quantifying common microplastics in a range of environmental samples. The method was initially developed by recovering 101% to 111% of spiked plastics on glass beads and was then applied to a composted municipal waste sample with spike recoveries ranging from 85% to 94%. The results from municipal waste samples and soil samples collected from an industrial area demonstrated that the method is a promising alternative for determining the concentration and identity of microplastics in environmental samples.

Stephen George Fuller and Anil Gautam, Environ. Sci. Technol., 2016, 50 (11), pp 5774–5780

The article

Is there any consistency between the microplastics found in the field and those used in laboratory experiments?

The ubiquitous presence and persistency of microplastics (MPs) in aquatic environments are of particular concern since they represent an increasing threat to marine organisms and ecosystems. Great differences of concentrations and/or quantities in field samples have been observed depending on geographical location around the world. The main types reported have been polyethylene, polypropylene, and polystyrene. The presence of MPs in marine wildlife has been shown in many studies focusing on ingestion and accumulation in different tissues, whereas studies of the biological effects of MPs in the field are scarce. If the nature and abundance/concentrations of MPs have not been systematically determined in field samples, this is due to the fact that the identification of MPs from environmental samples requires mastery and execution of several steps and techniques. For this reason and due to differences in sampling techniques and sample preparation, it remains difficult to compare the published studies. (…)

Nam Ngoc Phuong, Aurore Zalouk-Vergnoux, Laurence Poirier and al., Environmental Pollution, Volume 211, April 2016, Pages 111–123

The article

 

Laboratory Methods for the Analysis of Microplastics in the Marine Environment: Recommendations for quantifying synthetic particles in waters and sediments

“This document is a methods manual for measuring microplastic in the environment. This manual outlines step-by-step instructions for quantifying microplastic in marine environmental samples, including processes to streamline terminology and approaches.” (…)

Julie Masura, Joel Baker, Gregory Foster, and Courtney Arthur, NOAA Marine Debris Program, 39 p., July 2015

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