{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T00:44:24Z","timestamp":1776991464531,"version":"3.51.4"},"reference-count":45,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,2,4]],"date-time":"2026-02-04T00:00:00Z","timestamp":1770163200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Union\u2019s Horizon Europe research and innovation program PRecycling","doi-asserted-by":"publisher","award":["101058670"],"award-info":[{"award-number":["101058670"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>From the perspective of the circular economy and minimization of environmental pollution, recycling plastics is key for transforming polymeric waste streams (PWSs) towards reusable and, if possible, upgraded, value-added products. The low homogeneity of PWSs, even when sorted, complicates sampling, analytical characterization, processability, and quality assurance of the whole circular process. Therefore, sampling, sample preparation, and analysis methodologies that yield results accurate and representative enough to describe the contents and the safety of the bulk while being cost-effective are crucial. In this context, an experimental \u201cmodel waste\u201d approach was conceptualized to reliably assess and optimize sampling and sample preparation strategies towards specific goals, i.e., identifying and precisely quantifying different polymer types and non-polymeric contaminants (such as brominated flame retardants, BFR) along with establishing a correlation of the sample preparation steps with low deviation values between replicates. The results indicated that cryogenic grinding better preserved additive content, minimizing its degradation, i.e., 461 \u00b1 17 ppm determined via HPLC-MS when the nominal concentration was 500 ppm. On the other hand, melt-based homogenization significantly improved homogeneity and hence reproducibility\/variability of analytical results (RSD), albeit at the risk of partial additive thermal degradation (up to 70% reduction in BFR content). The current experimental approach allows a clear understanding of plastic waste characteristics in view of demonstrating analytical limits of detection (LoD), reliable verification of compliance with certain concentrations of unwanted contaminants, and eventually robust evaluation of the applied recycling scheme efficiency.<\/jats:p>","DOI":"10.3390\/polym18030409","type":"journal-article","created":{"date-parts":[[2026,2,4]],"date-time":"2026-02-04T13:56:23Z","timestamp":1770213383000},"page":"409","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Taming Waste Heterogeneity for Plastics Circularity with Optimized Sample Preparation Protocols for Quality Assessment"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4818-9813","authenticated-orcid":false,"given":"Christos","family":"Panagiotopoulos","sequence":"first","affiliation":[{"name":"Laboratory of Polymer Technology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 157 72 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1357-245X","authenticated-orcid":false,"given":"Christina","family":"Podara","sequence":"additional","affiliation":[{"name":"Research Lab of Advanced, Composites, Nanomaterials and Nanotechnology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 157 72 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6058-9369","authenticated-orcid":false,"given":"Eleni","family":"Gkartzou","sequence":"additional","affiliation":[{"name":"Research Lab of Advanced, Composites, Nanomaterials and Nanotechnology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 157 72 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6758-212X","authenticated-orcid":false,"given":"Melpo","family":"Karamitrou","sequence":"additional","affiliation":[{"name":"Research Lab of Advanced, Composites, Nanomaterials and Nanotechnology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 157 72 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0590-9016","authenticated-orcid":false,"given":"Tatjana","family":"Kosanovic-Milickovic","sequence":"additional","affiliation":[{"name":"Research Lab of Advanced, Composites, Nanomaterials and Nanotechnology, School of Chemical Engineering, Zographou Campus, National Technical University of Athens, 157 72 Athens, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mara","family":"Silber","sequence":"additional","affiliation":[{"name":"Group Research, BASF SE, 67056 Ludwigshafen am Rhein, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8736-2191","authenticated-orcid":false,"given":"Lars","family":"Meyer","sequence":"additional","affiliation":[{"name":"Group Research, BASF SE, 67056 Ludwigshafen am Rhein, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4185-1154","authenticated-orcid":false,"given":"Bernhard","family":"von Vacano","sequence":"additional","affiliation":[{"name":"Group Research, BASF SE, 67056 Ludwigshafen am Rhein, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ana Rita Carvalho","family":"Neiva","sequence":"additional","affiliation":[{"name":"Coolrec Plastics BV, Van Hilststraat 7, 5145 RK Waalwijk, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jan-Hendrik","family":"Knoop","sequence":"additional","affiliation":[{"name":"Fraunhofer Institute for Process Engineering and Packaging IVV, 85354 Freising, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6059-2624","authenticated-orcid":false,"given":"Asunci\u00f3n","family":"Mart\u00ednez-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Innovative Materials and Manufacturing Area, AIJU, Technological Institute for Children\u2019s Products and Leisure, 03440 Ibi, Alicante, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7160-4202","authenticated-orcid":false,"given":"Ana","family":"Ib\u00e1\u00f1ez-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Innovative Materials and Manufacturing Area, AIJU, Technological Institute for Children\u2019s Products and Leisure, 03440 Ibi, Alicante, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Silvia","family":"Pavlidou","sequence":"additional","affiliation":[{"name":"MIRTEC S.A., 76th km Athens-Lamia 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