Comparison of pyrolysis gas chromatography/mass spectrometry and hyperspectral FTIR imaging spectroscopy for the analysi

  • PDF / 817,603 Bytes
  • 16 Pages / 595.276 x 790.866 pts Page_size
  • 74 Downloads / 207 Views

DOWNLOAD

REPORT


PAPER IN FOREFRONT

Comparison of pyrolysis gas chromatography/mass spectrometry and hyperspectral FTIR imaging spectroscopy for the analysis of microplastics Sebastian Primpke 1

&

Marten Fischer 2 & Claudia Lorenz 1,3 & Gunnar Gerdts 1 & Barbara M. Scholz-Böttcher 2

Received: 31 July 2020 / Revised: 16 September 2020 / Accepted: 28 September 2020 # The Author(s) 2020

Abstract Analysis of microplastics (MP) in environmental samples is an emerging field, which is performed with various methods and instruments based either on spectroscopy or thermoanalytical methods. In general, both approaches result in two different types of data sets that are either mass or particle number related. Depending on detection limits of the respective method and instrumentation the derived polymer composition trends may vary. In this study, we compare the results of hyperspectral Fourier-transform infrared (FTIR) imaging analysis and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) analysis performed on a set of environmental samples that differ in complexity and degree of microplastic contamination. The measurements were conducted consecutively, and on exactly the same sample. First, the samples were investigated with FTIR using aluminum oxide filters; subsequently, these were crushed, transferred to glass fiber filters, in pyrolysis cups, and measured via Py-GC/MS. After a general data harmonization step, the trends in MP contamination were thoroughly investigated with regard to the respective sample set and the derived polymer compositions. While the overall trends in MP contamination were very similar, differences were observed in the polymer compositions. Furthermore, polymer masses were empirically calculated from FTIR data and compared with the Py-GC/MS results. Here, a most plausible shape-related overestimation of the calculated polymer masses was observed in samples with larger particles and increased particle numbers. Taking into account the different measurement principles of both methods, all results were examined and discussed, and future needs for harmonization of intermethodological results were identified and highlighted. Keywords Intercomparison . Py-GC/MS . FTIR . Spectroscopy . Mass spectrometry . Environmental samples

Introduction Microplastic (MP) particles [1] are considered as a new pollutant in the environment and their analysis is an emerging field in

analytical chemistry [2–5]. The ubiquitous pollution with MP causes concern to society and governments, and first legislations to govern MP in the marine environment, as well as in consumer products, are in preparation, e.g., in California, USA [6–8].

Sebastian Primpke and Marten Fischer contributed equally to this work. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00216-020-02979-w) contains supplementary material, which is available to authorized users. * Sebastian Primpke [email protected] * Barbara M. Scholz-Böttcher [email protected] 1

Alfred-Wegener-Institute Helmholtz Centre for Polar and M