MICROPLASTIC IN ENVIRONMENTAL SAMPLES: QUANTITATIVE DETERMINATION AND METROLOGICAL TRACEABILITY

ULRIKE BRAUN1, ROLAND BECKER1

CLAUS G. BANNICK2

RAINER STOSCH3

1 Bundesanstalt für Materialforschung und –prüfung (BAM)2 Umweltbundesamt (UBA)3 Physikalisch-Technische Bundesanstalt (PTB)

1st December 2015

Facts Microplastics (MP)

10 mm

• Increasing plastic production (300 mio t/a): founds in environment nearly everywhere

• Microplastics (few µm up to 5mm) • Primary microplastic: cosmetics, technical abrasives (~ 0,5 kilo t/a)

• Secondary microplastic: degradated polymers by UV, O2, mechanics (~ 8-10 mio t/a)

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MP Particles: Possible Risks

• Release of toxic decomposition products to environment during degradation (decomposition products of polymer, additives)

• Adsorption of persistent pollutants, ingestion to animals and accumulation of pollution in food chain

• Carrier for vectors of different biologic species

No verified data exist about the kind and amount, the source and the fate as well as the behaviour of microplastic particles in the

environment.

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Analytic problem: a few synthetic polymer particles with different material characteristics (density, solubility) beside many natural,

macromolecular particles in various environmental matrices

MP Particles in Environment: Analysis

4

• Harmonized sampling /sample preparation from various environmental matrices (water, soil, biota).

• Routine analysis for identification, quantitative determination and metrological traceability.

• Assessment of risks (persistent pollutants, microbiology).

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MP Particles in Environment: Analysis

5

• Routine analysis for identification, quantitative determination and metrological traceability.

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Raman Spectroscopy MappingExample: Sand + 2wt% PE, laser wavelength 488 nm

Mapping 472 cm-1Mapping 2888 cm-1

Spectra PE Spectra sand

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Raman Mapping Quantification

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traceability to length (m)metrological AFM (PTB)

fcal,x/y

surface coverage:(x ± Ux) % px , py: structure period

2 µmpy

px

PTB Raman calibration standard

Raman mapping of calibrated„chessboard“ pattern

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Conclusion Raman Mapping

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• Certain identification is possible, determination of particle sizes (microbiologic interaction).

• Non destructive method.

• Major disadvantage: fluorescence of matrix and high resolution /black matrix can lead to the melting of polymers.

• Automatisation by use of calibration standard and quantitative result.

2015-12-01 EMPIR Workshop, Turin, Italy

10 mm

Thermo-Analytic MethodsAssessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry, E. Duemichen, U. Braun, R. Senz, G. Fabian, H. Sturm, Journal of Chromatography A 2014, 1354, 117-128.

Adsorber (Twister)

Macroscopic sampling

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TDS-GC-MS Analysis

• Characteristic decomposition products of polymers

• Identification via „fingerprint“ or spectra libraries

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10 12 14 16 18 20 22 24 26 28 30 32 34

14.6 14.7 17.4 20.0 22.4 22.6 25.0 27.2 29.3 31.3 31.4

PE

Suspended solids

Soil

Mussel

m/z = 55

Abu

ndan

ce

Retention time / min

PE

Suspended solids

Soil

Musselm/z = 55

6

912

15

1821

243

PE in Environmental SamplesAnalysis of polyethylene microplastics in environmental samples, using a thermal decomposition method, E. Dümichen, A.-K. Barthel, U. Braun, C. G. Bannick, K. Brand, M. Jekel, R. Senz Water Research Vol. 85, 2015, 451–457.

10

Retention time / min

Abu

ndan

ce

20 21 22 23 24 25 26

LD-PE

1,15-Hexadecadiene1-HexadeceneHexadecane

1,14-Pentadecadiene1-PentadecenePentadecane

HD-PE

new PE Microscrub

PE Microscrub after H2O2 treatment

Abu

ndan

ce

Retention time / min

PE after oxidativestorage (autoclave)

1,13-Tetradecadiene1-TetradeceneTetradecane

*

*

*

*

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• Certain identification of PE in sample

• Identification of polymers in environmental samples (PE, PP)

• Quantification (bulk method) is possible by use of calibration standards.

• Major disadvantages: destructive method, no information about particle contribution

• Improvement of method, automatisation, limit of detection.

Conclusion Thermo-Analytic Methods

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• Standardisation of methods for microplastic analysis in environmental samples: Raman Mapping, Thermo-analytic methods, ...

• Assessment of metrological traceability.

• Development and provision of reference materials.

Possible objective for a project contribution

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Thank you