Overview of Sampling and QA/QC Guidance for Microplastics Research
As microplastics research expands into regulatory monitoring, risk assessment, and long-term environmental surveillance, sampling rigor and contamination control have become decisive factors in data quality and comparability. The guidance by Brander et al. (2020) provides one of the most comprehensive and widely cited frameworks for sampling design and QA/QC in microplastics research across environmental matrices .
This resource is frequently used alongside Plastiverse tools focused on sampling methods, analytical identification, and QA/QC harmonization, and serves as a conceptual backbone for many applied monitoring programs.
Why This Sampling and QA/QC Guidance Matters
Microplastics are ubiquitous in air, water, sediment, and laboratory environments, making them uniquely vulnerable to false positives and biased results. Brander et al. emphasize that inconsistent QA/QC practices—not analytical sensitivity—are now one of the largest sources of uncertainty in reported microplastics concentrations .
This guidance is especially relevant for:
- Regulatory and compliance monitoring programs
- Drinking water and wastewater studies
- Cross-laboratory comparisons and meta-analyses
- Studies informing exposure and probabilistic risk assessment
Core Elements of the Framework
1. Study Design Comes First
Sampling strategies must be explicitly aligned with the research question, matrix, particle size range of interest, and downstream analysis methods. Discovery-based surveys, mitigation assessments, and risk-oriented studies each require different design choices .
Key considerations include:
- Source and pathway of microplastics
- Target matrix (air, water, sediment, biota, sludge)
- Spatial and temporal replication
- Anticipated size distributions and polymer types
➡️ See related tools:
- Microplastics Sampling Tools & Gear
- Microplastics Sampling Method Selection Tool
- RSVP – Representative Sample Volume Predictions Tool
2. Contamination Control Is Central
Because airborne fibers and plastic labware are common contamination sources, the guidance stresses good field practices and good laboratory practices (GLPs) as foundational—not optional—components of any study .
Recommended practices include:
- Preferential use of glass and metal equipment
- Pre-filtering all reagents and working solutions
- Wearing natural-fiber clothing and lab coats
- Isolating samples during processing and analysis
3. Blanks, Background Checks, and Controls
Brander et al. outline a structured approach to field blanks, procedural blanks, and background deposition controls, allowing contamination to be quantified, corrected for, or used to define detection limits .
Common tools include:
- Open or wetted filter blanks during sampling
- Laboratory procedural blanks processed alongside samples
- Use of blanks to establish limits of detection (LOD) and quantification (LOQ)
➡️ Learn more:
4. Matrix-Specific Sampling Guidance
The paper provides matrix-tailored recommendations spanning drinking water, wastewater, sludge/biosolids, surface waters, air, and sediments, recognizing that no single protocol fits all matrices .
Examples include:
- Large-volume sampling for clean matrices (e.g., drinking water)
- Composite and flow-weighted sampling for wastewater
- Depth-integrated or paired sampling approaches for surface waters
- Shallow-depth and transect-based sampling for sediments
➡️ Internal links:
5. Reporting, Transparency, and Reuse
To support comparability and future synthesis, the guidance stresses complete reporting of QA/QC outcomes, including blank results, recovery efficiencies, and size detection limits—not just final concentrations .
Citation
Brander, S. M., Renick, V. C., Foley, M. M., et al. (2020). Sampling and quality assurance and quality control: A guide for scientists investigating the occurrence of microplastics across matrices. Applied Spectroscopy, 74(9), 1099–1125.