Abstract
Micro-Fourier transform infrared (micro-FTIR) spectroscopy and Raman spectroscopy enable the reliable identification and quantification of microplastics (MPs) in the lower micron range. Since concentrations of MPs in the environment are usually low, the large sample volumes required for these techniques lead to an excess of coenriched organic or inorganic materials. While inorganic materials can be separated from MPs using density separation, the organic fraction impedes the ability to conduct reliable analyses. Hence, the purification of MPs from organic materials is crucial prior to conducting an identification via spectroscopic techniques. Strong acidic or alkaline treatments bear the danger of degrading sensitive synthetic polymers. We suggest an alternative method, which uses a series of technical grade enzymes for purifying MPs in environmental samples. A basic enzymatic purification protocol (BEPP) proved to be efficient while reducing 98.3 ± 0.1% of the sample matrix in surface water samples. After showing a high recovery rate (84.5 ± 3.3%), the BEPP was successfully applied to environmental samples from the North Sea where numbers of MPs range from 0.05 to 4.42 items m-3. Experiences with different environmental sample matrices were considered in an improved and universally applicable version of the BEPP, which is suitable for focal plane array detector (FPA)-based micro-FTIR analyses of water, wastewater, sediment, biota, and food samples.
| Original language | English |
|---|---|
| Journal | Environmental Science and Technology |
| Volume | 51 |
| Issue number | 24 |
| Pages (from-to) | 14283-14292 |
| Number of pages | 10 |
| ISSN | 0013-936X |
| DOIs | |
| Publication status | Published - 19 Dec 2017 |
Bibliographical note
Funding Information:The authors would like to thank the German Federal Ministry of Education and Research and the Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research (AWI) for funding the projects MICROPLAST (BMBF grant 03F0631A) and BASEMAN (BMBF grant 03F0734A). Equally, we would like to thank the Bavarian State Ministry of the Environment and Consumer protection for funding the project ″Eintragsp-fade, Vorkommen und Verteilung von Mikroplastikpartikeln in bayerischen Gewassërn sowie mögliche Auswirkungen auf aquatische Organismen″. Furthermore, we would like to thank ASA Spezialenzyme GmbH for their support with the optimization of the enzyme incubation conditions, Ursula Wilczek for her support in the laboratory, and finally, all the members of the MPs groups of the AWI and University of Bayreuth for fruitful discussions.
Publisher Copyright:
© 2017 American Chemical Society.