An interlaboratory comparison on the quantification of microplastics (polyethylene, polypropylene, polystyrene, polyethylene terephthalate) in a sedimented freshwater suspended matter involved twelve laboratories contributing with different thermoanalytical procedures. Methods included pyrolysis gas chromatography-mass spectrometry (py-GC-MS), thermal extraction and desorption followed by GC-MS (TED-GC-MS), thermogravimetry coupled to infrared spectroscopy or to mass spectrometry, differential scanning calorimetry, a micro combustion calorimetric procedure and a procedure based on elemental analysis. Though different combinations of sample pre-treatment, calibration and instrumental settings for polymer identification and quantification were applied the procedures based on GC-MS were able to correctly identify all polymers and to report polymer quantification results with reasonable between-laboratory reproducibilities. Though the other methods displayed limitations regarding the detection of specific polymers, they nevertheless showed considerable potential as alternative approaches for the quantification of microplastics in solid environmental matrices.
Quantification of microplastics in a freshwater suspended organic matter using different thermoanalytical methods – outcome of an interlaboratory comparison
Roland Becker, Korinna Altmann, Thomas Sommerfeld, Ulrike Braun
published in Journal of Analytical and Applied Pyrolysis, Vol. 148, pages 104829, 2020
BAM, division Physical and Chemical Analysis of Polymers and division Organic Trace and Food Analysis