onitoring and identification of microplastics › documents › postkod2017 › mtg050317... ·...

MONITORING AND IDENTIFICATION

OF MICROPLASTICS

Mikhail Durkin

PlasticFreeBaltic Project Meeting

Stockholm, 5 January 2017

FOR PROTECTION OF THE BALTIC SEA ENVIRONMENT

co-funded by EU LIFE Programme

Microplastics


Goals


1. Test the methodology

2. Adapt to public monitoring purposes

3. Compile first round of results

4. Update River Watch Manual with microplastic monitoring method

5. Disseminate the results

Steps to be considered


1. Preparatory work, planning (devising sampling points, schedule, etc)

2. Assemble of equipment

- a pump and hoses…

- filter consisting of different mesh sizes…

3. Cleanliness of equipment (filter to avoid ‘contamination’ with microfibers/particles etc.)

4. Sampling process (e.g. containers to be used, duration, volume to be pumped etc)

5. Analysis of samples (microscoping etc, which particles to expect)

6. Alternative analysis

7. Recording of data

Preparatory work, planning


Where, when, how and why?

1. Decide upon sampling points

• Accessibility (easy and cheap to reach, safety)

• Potential hotspots (e.g. waste- or stormwater discharges)

• Background station (to enable comparability)

2. Set up monitoring frequency

• Seasons (to catch peaks)

• Correspond to already ongoing monitoring

3. Equipment

• Purchase/use available - tbd

4. Train monitoring staff

• Volunteers, RW

Pump: 2,2 kW / 100 l/minFilters: 20 µm and 300 µm mesh sizeHoses: 1,5 and 1 inchPipes: 2 inch, stainless steel


Assemble of equipment

Equipment used for sampling of microplastics. On the left hand side: filter holder consisting of stainless steel pipes with a chamfer for gaskets, a nylon filter and a corresponding clamp. The filter holder was designed with a bend only to improve sampling in very shallow waters and to decrease the risk of sediments being filtered. To the right is the gasoline driven water pump connected to the filter holder and a red volumeter.

Cleanliness of equipment


Avoid ‘contamination’ with microfibers/particles etc.)

• Cotton clothing for sampling personnel

• Samples to be handled upwind

• filtrate to be released downstream to avoid it being filtered twice

• More detailed: Guide to microplastic identification

• Contamination can be quantified by taking control samples, for example by quickly stopping the pump directly after starting it and thereby, not letting any significant amounts of water pass through the filter

http://stjohns.ifas.ufl.edu/sea/documents/MERI_Guide to Microplastic Identification.pdf

Methods to avoid contamination


1. Keep your filter covered whenever possible. If you are not looking at it under the microscope, it should be covered.

2. Store filters in glass petri dishes. Plastic petri dishes will work, but glass is better to reduce possible contamination from the dish itself.

3. Wipe down all surfaces before inspecting each sample. A brightly colored sponge is recommended. Any pieces sourced from the sponge will be more easily identified ascontamination if it is a unique color.

4. Rinse all tweezers, probes, and your hands three times under a heavy stream of water before opening a petri dish for inspection.

5. Wear cotton or natural fiber clothes. Avoid bringing any synthetic materials into lab.

6. Minimize traffic in your lab or working space, if possible. The smaller the number of people in and out of your work space, the smaller the chance of contamination.

Sampling process


• Filter holder thoroughly rinsed with clean water

• Clean filter inserted with a pair of tweezers.

• Filter holder submersed and fixed at constant depth.

• Pump started and run until the desired filtered volume was reached.• 300 µm filters – several thousand liters• 20 µm filters – 10-70 liters (clogging)

• Pumping halted well before the filter would clog for easier analysis.

• Filter holder raised from the water

• Filter placed in its sealed petri dish using a pair of tweezers.

• Filtrate volume noted down.

• Procedure repeated for the desired number of replicates.

Complementary sampling- Filtration through 20 µm filters

Also- Simple melting test- FTIR spectroscopy


Analysis of samples/microscoping



• A grid drawn on both the bottom of the petri dishes and on a notebook paper. The grid lines should be visible through the filters.

• Particle position, size and appearance scored and categorized one square at a time with the lid kept on the petri dishes to avoid contamination. Particles can be also photographed.

• After quantification, the petri dish lids were removed and suspected microplastics in need of further inspection were transferred to a clean part of the filter with a pair of micro tweezers for further determination. Identification and detection was facilitated by carefully moisturizing the filters by water.

• Some particles, suspected to be of synthetic origin, transferred to a glass slide and heated over a Bunsen burner. Particles that melted were considered as synthetic.

• individual particles analysed by Fourier Transform Infrared (FT-IR) Spectroscopy


Recording the results

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