Common laboratory reagents: Are they a double-edged sword in microplastics research?

Understanding and communicating instances of microplastic contamination is critical for enabling plastic-free transitions. While microplastics research uses a variety of commercial chemicals and laboratory liquids, the impact of microplastics on these materials remains unknown. To fill this knowledge gap, the current study investigated microplastics abundance and their characteristics in laboratory waters (distilled, deionized, and Milli-Q), salts (NaCl and CaCl2), chemical solutions (H2O2, KOH and NaOH), and ethanol from various research laboratories and commer-cial brands. The mean abundance of microplastics in water, salt, chemical solutions, and ethanol samples was 30.21 +/- 30.40 (L-1), 24.00 +/- 19.00 (10 g(-1)), 187.00 +/- 45.00 (L-1), and 27.63 +/- 9.53 (L-1), respectively. Data comparisons revealed significant discrepancies between the samples in terms of microplastic abundance. Fibers (81 %) were the most common microplastics, followed by fragments (16 %) and films (3 %); 95 % of them were < 500 mu m, with the smallest and largest particle sizes recorded being 26 mu m and 2.30 mm, respectively. Microplastic polymers discovered included polyethylene, polypropylene, polyester, nylon, acrylic, paint chips, cellophane, and viscose. These findings lay the groundwork for identifying common laboratory reagents as a potential contributor to microplastic contamina-tion in samples, and we offer solutions that should be integrated into data processing to produce accurate results. Taken together, this study shows that commonly used reagents not only play a key role in the microplastic separation process but also contain microplastic contamination themselves, requiring the attention of researchers to promote quality control during microplastic analysis and commercial suppliers in formulating novel prevention strategies.

Automated summary

Understanding and communicating instances of microplastic contamination is crucial for plastic-free transitions. Laboratory waters, salts, chemical solutions, and ethanol samples were found to contain varying levels of microplastics, mainly consisting of fibers, fragments, and films. The study highlights the importance of quality control during microplastic analysis and the need for prevention strategies to tackle microplastic contamination in commonly used reagents.