TY - JOUR A1 - Putzu, Mara A1 - Wiesner, Yosri A1 - Weimann, Christiane A1 - Hodoroaba, Vasile-Dan A1 - Muniategui Lorenzo, Soledad A1 - Fernández-Gonzáles, Verónica A1 - Booth, Andy M. A1 - Igartua, Amaia A1 - Benismail, Nizar A1 - Coïc, Laureen A1 - Chivas-Joly, Carine A1 - Fenoglio, Ivana A1 - Rossi, Andrea Mario A1 - Giovannozzi, Andrea Mario A1 - Altmann, Korinna T1 - Optimization of tablet processing as a reference material for microplastic detection methods N2 - Reference materials (RMs) are essential and highly demanded tools for the development and validation of methods for microplastic (MP) quantification in complex matrices, to ensure comparable and harmonized approaches aligned with EU commission criteria for monitoring MPs (e.g., Drinking Water Directive and Urban Wastewater Treatment Directive). This study investigates different approaches for optimizing the production of polypropylene (PP) RMs in the form of water-soluble tablets, which were carefully evaluated for their homogeneity and stability according to ISO Guide 30, ISO 33401, and ISO 33405. PP particles (1–100 μm) were produced by cryomilling and embedded in a lactose/PEG matrix, then pressed into tablets (18 µg theoretical PP mass). The production process was optimized by varying (i) the size distribution of the matrix components and (ii) the mixer instrument. The materials obtained were characterized by thermogravimetric analysis to assess the homogeneity distribution of MPs with respect to PP mass in the individual tablets and their stability over a 4-month period. The most promising approach, with a homogenous mass of 19 μg (standard deviation of 4 μg), relative standard deviation of 19%, was further investigated for homogeneity by comparison with thermo-analytical mass determination methods, such as TED-GC/MS (thermal extraction desorption-gas chromatography/mass spectrometry) and Py-GC/MS (pyrolysis-gas chromatography-mass spectrometry), and for number-based characterization using micro-Raman spectroscopy. Material characterization was also examined using laser diffraction, scanning electron microscopy, and ATR-FTIR. Based on the results, the optimized processing protocol yields a PP RM suitable for quality control and method performance studies supporting standardization. KW - Microplastics KW - TED-GC/MS KW - Reference materials KW - Polypropylene PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653290 DO - https://doi.org/10.1007/s00216-025-06271-7 SN - 1618-2642 SP - 1 EP - 14 PB - Springer Science and Business Media LLC AN - OPUS4-65329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Putzu, Mara A1 - Barbaresi, Marta A1 - Fadda, Marta A1 - Sacco, Alessio A1 - Piergiovanni, Maurizio A1 - Masino, Matteo A1 - Bianchi, Federica A1 - Altmann, Korinna A1 - Benismail, Nizar A1 - Coïc, Laureen A1 - Fenoglio, Ivana A1 - Mattarozzi, Monica A1 - Rossi, Andrea Mario A1 - Careri, Maria A1 - Giovannozzi, Andrea Mario T1 - Accuracy assessment of a micro-Raman spectroscopy method for small microplastic particles in infant milk formula N2 - The presence of microplastics (MPs) in the food chain is increasingly documented, raising concerns over potential risks to human health. Despite growing efforts, standardized methods for MPs detection in food matrices remain limited. This study presents an interlaboratory comparison (ILC) aimed at assessing the accuracy and comparability of an analytical approach for the identification and quantification of small MPs (5–100 μm) in infant milk powder using μ-Raman spectroscopy and a representative polyethylene terephthalate (PET) reference material (RM). The RM, formulated as water-soluble tablets, was designed to replicate the morphology, size distribution, and polymer composition of environmentally relevant MPs, and was previously assessed for homogeneity and stability for mass fraction and particle numbers. The approach was assessed using two PET RM batches with different MPs particle numbers (high load batch: 1759 ± 141 MPs; low load batch: 160 ± 22 MPs), subjected to an enzymatic–chemical digestion, followed by μ-Raman analysis performed independently in two laboratories with different instruments and operators. Results are reported as absolute particle counts per analyzed sample and demonstrated excellent recovery across all size classes, including the smallest particles (down to 5 μm), with recovery rates ranging from 82 % to 88 %, in good agreement with the RM reference values. The analytical approach proved to be robust, reproducible, and suitable for low-level MPs quantification in complex food matrices, supporting ongoing efforts toward method harmonization and standardization for reliable MPs monitoring in the food sector. KW - Microplastics KW - Milk KW - Raman microspectroscopy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646239 DO - https://doi.org/10.1016/j.talo.2025.100586 SN - 2666-8319 VL - 12 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-64623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -