Abstract
Quality assurance and quality control (QA/QC) techniques are critical to analytical chemistry, and thus the analysis of microplastics. Procedural blanks are a key component of QA/QC for quantifying and characterizing background contamination. Although procedural blanks are becoming increasingly common in microplastics research, how researchers acquire a blank and report and/or use blank contamination data varies. Here, we use the results of laboratory procedural blanks from a method evaluation study to inform QA/QC procedures for microplastics quantification and characterization. Suspected microplastic contamination in the procedural blanks, collected by 12 participating laboratories, had between 7 and 511 particles, with a mean of 80 particles per sample (±SD 134). The most common color and morphology reported were black fibers, and the most common size fraction reported was 20–212 μm. The lack of even smaller particles is likely due to limits of detection versus lack of contamination, as very few labs reported particles <20 μm. Participating labs used a range of QA/QC techniques, including air filtration, filtered water, and working in contained/‘enclosed’ environments. Our analyses showed that these procedures did not significantly affect blank contamination. To inform blank subtraction, several subtraction methods were tested. No clear pattern based on total recovery was observed. Despite our results, we recommend commonly accepted procedures such as thorough training and cleaning procedures, air filtration, filtered water (e.g., MilliQ, deionized or reverse osmosis), non-synthetic clothing policies and ‘enclosed’ air flow systems (e.g., clean cabinet). We also recommend blank subtracting by a combination of particle characteristics (color, morphology and size fraction), as it likely provides final microplastic particle characteristics that are most representative of the sample. Further work should be done to assess other QA/QC parameters, such as the use of other types of blanks (e.g., field blanks, matrix blanks) and limits of detection and quantification.
| Original language | English (US) |
|---|---|
| Article number | 138883 |
| Journal | Chemosphere |
| Volume | 333 |
| DOIs | |
| State | Published - Aug 2023 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank all participants of the method evaluation study including: Alfred-Wegener-Institute; Algalita Marine Research and Education; Barnett Technical Services; BASF; California State University (Bakersfield); California State University (Channel Islands); East China Normal University; Eastman Chemical Company; U.S. Environmental Protection Agency; Eurofins (Australia, Norway, US); HORIBA Scientific; Innovations institut für Nanotechnologie und korrelative Mikroskopie; Institute of Hydrobiology (Chinese Academy of Sciences); Jinan University; NatureWorks LLC; Metropolitan Water District; Norwegian Institute for Water Research; Ontario Ministry of the Environment, Conservation and Parks; Orange County Sanitation District; Oregon State University; Pennsylvania State University; RJ Lee Group; Southern California Coastal Water Research Project Authority; Thermo Fisher (US); University of California (Riverside); University of Minnesota (Duluth); University of Quebec at Rimouski; University of Toronto. We thank R. Butler and Z. Quraishi at SCCWRP for helping with the database. We thank Devin Edge (University of Minnesota Duluth), Nina T. Buenaventura (NIVA), Cecilie Singdahl-Larsen (NIVA), Amy Fetters (California State University Bakersfield) for assisting with sample processing. Sample processing in the Minor Lab was funded by a cooperative agreement between the National Park Service and the University of Minnesota with support from the Great Lakes Restoration Initiative and the National Park Service Water Resources Division. Funding was provided by the California State Water Resources Control Board and SCCWRP. Gray Lab involvement was supported in part by the USDA NIFA Hatch program (Project Number CA-R-ENS-5120-H) and Multistate Project W4170 funds.
Funding Information:
We thank all participants of the method evaluation study including: Alfred-Wegener-Institute; Algalita Marine Research and Education; Barnett Technical Services; BASF; California State University (Bakersfield); California State University (Channel Islands); East China Normal University; Eastman Chemical Company; U.S. Environmental Protection Agency; Eurofins (Australia, Norway, US); HORIBA Scientific; Innovations institut für Nanotechnologie und korrelative Mikroskopie; Institute of Hydrobiology (Chinese Academy of Sciences); Jinan University; NatureWorks LLC; Metropolitan Water District; Norwegian Institute for Water Research; Ontario Ministry of the Environment, Conservation and Parks; Orange County Sanitation District; Oregon State University; Pennsylvania State University; RJ Lee Group; Southern California Coastal Water Research Project Authority; Thermo Fisher (US); University of California (Riverside); University of Minnesota (Duluth); University of Quebec at Rimouski; University of Toronto. We thank R. Butler and Z. Quraishi at SCCWRP for helping with the database. We thank Devin Edge (University of Minnesota Duluth), Nina T. Buenaventura (NIVA), Cecilie Singdahl-Larsen (NIVA), Amy Fetters (California State University Bakersfield) for assisting with sample processing. Sample processing in the Minor Lab was funded by a cooperative agreement between the National Park Service and the University of Minnesota with support from the Great Lakes Restoration Initiative and the National Park Service Water Resources Division. Funding was provided by the California State Water Resources Control Board and SCCWRP. Gray Lab involvement was supported in part by the USDA NIFA Hatch program (Project Number CA-R-ENS-5120-H ) and Multistate Project W4170 funds.
Publisher Copyright:
© 2023 Elsevier Ltd
Keywords
- Controls
- Cross contamination
- Methods
- Plastic
- Procedural contamination
- QA/QC
PubMed: MeSH publication types
- Journal Article