Microplastics and Nanoplastics (MNP) Testing

Polymer Identification and Mass-Based Quantitation by Pyrolysis-GC/MS

Microplastics and nanoplastics are increasingly important considerations in environmental monitoring, product development, packaging evaluation, pharmaceutical research, medical device testing, food and beverage studies, and materials characterization.

CA Analytical Testing Services provides customized microplastics and nanoplastics testing using pyrolysis gas chromatography–mass spectrometry, or Py-GC/MS. Our testing platform combines a GERSTEL PYRO solution with GC/MS to identify polymer-specific thermal decomposition products and determine the mass of targeted polymers within a sample.

Our approach is designed for organizations that need more than a simple presence-or-absence result. We help clients answer the questions that matter:

• Which polymers are present?
• How much of each targeted polymer is present?
• Is the material consistent with a suspected contamination source?
• Does polymer burden change between products, processes, sampling locations, or time points?
• Can the method produce reproducible, scientifically defensible data in the relevant sample matrix?

Why Test for Microplastics and Nanoplastics?

Microplastics are generally described as plastic particles smaller than 5 millimeters. Nanoplastics represent the smaller end of the particle-size range and are commonly described as particles below approximately 1 micrometer, although definitions continue to evolve.

These materials may originate from the breakdown of larger plastic products or may be introduced as small particles during manufacturing, processing, packaging, use, abrasion, or environmental exposure.

Potential sources include:

• Plastic packaging and containers
• Synthetic textiles and fibers
• Tubing, seals, filters, and processing equipment
• Pharmaceutical and medical device materials
• Consumer and personal care products
• Tire and road-wear particles
• Paints, coatings, and building materials
• Industrial manufacturing processes
• Wastewater and environmental contamination
• Airborne fibers and particulate matter

Because plastics vary in composition, particle size, morphology, weathering history, additives, and matrix interactions, MNP analysis requires a testing strategy built around the specific scientific question—not simply the use of a single instrument.

How Pyrolysis-GC/MS Works

Pyrolysis-GC/MS identifies polymers through their characteristic thermal decomposition products.

During analysis, the prepared sample is heated under controlled conditions in the GERSTEL pyrolysis system. Polymeric materials break down into smaller, characteristic compounds known as pyrolysis products or pyrolysates.

These compounds are then:

1. Transferred into the gas chromatograph.
2. Separated according to their chemical properties.
3. Detected by mass spectrometry.
4. Evaluated using polymer-specific marker compounds and ions.

The resulting chemical profile can be used to identify targeted polymer types and, when supported by appropriate calibration and quality controls, quantify polymer mass.

Unlike microscopy-based techniques, Py-GC/MS does not depend on visually locating and counting individual particles. It measures the chemical signal produced by the polymer material collected in the analytical sample.

The GERSTEL PYRO Advantage

CA Analytical’s GERSTEL PYRO solution provides a flexible and controlled platform for thermal analysis coupled with GC/MS.

Depending on the project and sample requirements, the system supports multiple analytical approaches, including:

• Pulsed pyrolysis
• Sequential pyrolysis
• Fractionated pyrolysis
• Controlled temperature programs
• Thermal desorption followed by pyrolysis
• Cryofocusing of generated compounds
• Automated sample introduction
• Analysis of solid and liquid samples

The ability to perform thermal desorption and pyrolysis sequentially can be particularly useful for complex materials. Volatile and semi-volatile compounds may first be characterized or removed before the remaining polymer fraction is pyrolyzed. This can reduce interference, improve interpretation, and provide additional information from a single prepared sample.

Precise control of pyrolysis conditions is important because temperature, heating rate, sample preparation, polymer concentration, and matrix composition can all affect the resulting pyrogram.

Our Microplastics and Nanoplastics Testing Services

Polymer Identification

We analyze characteristic pyrolysis markers to identify targeted polymers in environmental, product, process, and research samples.

Testing may be developed for common polymer classes such as:

• Polyethylene
• Polypropylene
• Polystyrene
• Polyethylene terephthalate
• Polyvinyl chloride
• Polycarbonate
• Polyamides
• Polymethyl methacrylate
• Polyurethane
• Styrenic and other engineered polymers

The final polymer panel depends on the sample matrix, project objective, reference materials, marker specificity, expected concentration range, and method-performance requirements.

Polymer-Specific Mass Quantitation

When supported by suitable calibration standards and validated sample preparation, Py-GC/MS can determine the mass of targeted polymers in the analyzed sample.

Results may be reported as appropriate for the study design, including:

• Polymer mass per sample
• Polymer mass per unit volume
• Polymer mass per unit weight
• Polymer-specific concentration
• Total targeted polymer burden
• Relative comparison between samples or study groups

Reporting units, target polymers, calibration ranges, and acceptance criteria are established during project planning.

Qualitative Screening and Unknown Polymer Investigation

For exploratory or investigative projects, CA Analytical can screen samples for polymer-related pyrolysis patterns and compare findings against suspected source materials or reference polymers.

This approach may be useful for:

• Contamination investigations
• Foreign-material analysis
• Product failure investigations
• Manufacturing troubleshooting
• Packaging comparisons
• Material verification
• Source attribution studies
• Research and feasibility assessments

Because complex polymer mixtures can produce overlapping thermal-decomposition products, tentative findings may require targeted confirmation, reference-material comparison, or additional method development.

Comparative and Source-Tracking Studies

Py-GC/MS can support controlled comparisons between:

• Finished products and raw materials
• Packaged and unpackaged samples
• Process inlet and outlet samples
• Upstream and downstream water samples
• Control and exposed samples
• New and aged materials
• Baseline and stability time points
• Suspected contaminants and potential source materials

These studies can help identify trends, evaluate process contributions, and investigate whether a specific material may be associated with the detected polymer profile.

Sample Types and Applications

Microplastics testing is highly matrix dependent. CA Analytical evaluates each sample type before recommending preparation and analysis conditions.

Potential matrices include:

Water and Environmental Samples

• Drinking water
• Purified and process water
• Surface water
• Groundwater
• Wastewater influent and effluent
• Marine water
• Sediment and soil
• Environmental particulate matter
• Air-sampling filters

Pharmaceutical and Medical Applications

• Pharmaceutical water
• Drug-product and formulation samples
• Packaging and container-closure materials
• Medical device extracts
• Process-contact materials
• Filters, tubing, seals, and components
• Manufacturing investigation samples
• Research samples and simulated-use extracts

Food, Beverage, and Consumer Products

• Bottled and packaged beverages
• Food-contact materials
• Consumer products
• Cosmetics and personal care products
• Product extracts
• Packaging migration studies
• Manufacturing-process samples

Industrial and Materials Applications

• Raw polymers
• Films, fibers, coatings, and composites
• Manufacturing residues
• Process water
• Filter media
• Unknown particulate material
• Weathered or degraded plastics
• Product-failure samples

Not every matrix can be tested using the same preparation procedure. Complex samples may require project-specific recovery studies, digestion, extraction, filtration, matrix removal, concentration, or other preparation steps.

Sample Preparation and Contamination Control

For MNP analysis, sample preparation is often as important as the instrumental analysis itself.

Plastic materials are widespread throughout ordinary laboratory and manufacturing environments. Sample containers, tubing, filters, wipes, gloves, clothing, airborne fibers, laboratory surfaces, and processing tools can introduce background contamination.

CA Analytical develops preparation and control strategies based on the sample matrix and project objectives. These may include:

• Contamination-controlled sample handling
• Procedural blanks
• Method blanks
• Field or transport blanks
• Matrix blanks, when available
• Laboratory control samples
• Spiked recovery samples
• Replicate preparations
• Polymer-free or low-background consumables
• Reference-material controls
• Carryover assessments
• Defined acceptance criteria

The controls included in a study are selected according to the intended use of the data, the sample matrix, and the level of method qualification required.

Method Development for Complex Matrices

A method that performs well for clean water may not perform adequately for wastewater, biological material, pharmaceutical formulations, food, tissue, packaging extracts, or industrial samples.

Complex matrices may:

• Suppress or distort polymer marker signals
• Produce interfering pyrolysis products
• Reduce polymer recovery
• Contain naturally occurring materials with overlapping markers
• Require digestion or matrix-removal procedures
• Introduce contamination during preparation
• Affect calibration accuracy and reproducibility

CA Analytical can develop and optimize matrix-specific methods that address sample preparation, polymer recovery, marker selection, calibration, blanks, detection capability, precision, and data interpretation.

Method-development programs may include:

1. Feasibility testing.
2. Selection of target polymers and reference materials.
3. Sample-preparation optimization.
4. Evaluation of polymer-specific marker compounds.
5. Calibration-model development.
6. Recovery and matrix-effect studies.
7. Precision and reproducibility testing.
8. Limit-of-detection and limit-of-quantitation assessments.
9. Blank and contamination-control evaluation.
10. Preparation of project-specific procedures and reports.

Testing in Support of ASTM and International Guidance

ASTM D8401-24 describes the use of Py-GC/MS for identifying polymer type and quantifying microplastic particles and fibers in water with high to low suspended-solids content. The standard covers treated drinking water, surface water, wastewater, and marine water and is intended to be used with related ASTM sample-collection and preparation practices.

CA Analytical can discuss testing strategies developed with reference to ASTM D8401-24 and relevant microplastics-analysis principles, including ISO 24187.

The applicability of a standard or published method must be evaluated for the actual matrix, target polymers, sample-preparation process, instrumentation, reporting requirements, and intended use of the results. Testing outside the validated scope of a published method may require additional feasibility work, method verification, or full matrix-specific method development.

Understanding What Py-GC/MS Results Mean

Py-GC/MS provides valuable chemical and mass-based information, but it does not independently answer every possible microplastics question.

Py-GC/MS responds to the polymer mass present in the prepared analytical sample. Therefore, claims regarding microplastic or nanoplastic size classifications depend on how the sample was collected, filtered, fractionated, and prepared before instrumental analysis.

When particle count, morphology, or size distribution is important, Py-GC/MS may need to be combined with microscopy, spectroscopy, particle-separation techniques, or other complementary methods.

Plastic Additives and Related Chemical Analysis

A microplastics project may extend beyond identification of the polymer itself.

Plastic materials can contain or release:

• Plasticizers
• Antioxidants
• Stabilizers
• Flame retardants
• Pigments and dyes
• Residual monomers
• Oligomers
• Processing aids
• Degradation products
• Metals and inorganic fillers
• Other extractable or leachable substances

CA Analytical’s broader analytical capabilities can support investigations into these associated chemicals through complementary techniques such as GC/MS, LC-MS, LC-QTOF, ICP-MS, and extractables and leachables testing.

This integrated approach can help distinguish between several different questions:

• Is polymeric material present?
• Which polymer is present?
• How much polymer is present?
• Which additives or degradation products are associated with it?
• Could the packaging, device, process, or raw material be the source?
• Are additional chemical characterization studies needed?

Why Choose CA Analytical?

Customized Study Design

We begin with the sample matrix, intended use of the data, target polymers, expected concentration range, and reporting objective.

Advanced Pyrolysis-GC/MS Technology

The GERSTEL PYRO platform provides controlled and flexible thermal analysis coupled with the chemical identification capabilities of GC/MS.

Method-Development Experience

Our scientists develop analytical procedures for challenging matrices rather than assuming that a generic method will perform adequately for every sample type.

Contamination-Controlled Workflows

Blanks, controls, sample-handling procedures, and recovery assessments are incorporated according to the needs of the project.

Broader Analytical Capabilities

When a project includes polymer additives, leachables, elemental contaminants, unknown compounds, or material-characterization questions, additional analytical techniques can be integrated into the investigation.

Defensible Data and Scientific Interpretation

Our goal is not simply to report a detected signal. We provide context regarding method scope, controls, limitations, uncertainty, and the conclusions supported by the data.

Start Your MNP Testing Project

Microplastics and nanoplastics projects often require early discussion of sampling, containers, preparation, target polymers, controls, and reporting expectations.

Contact CA Analytical before collecting or shipping samples so our scientists can help determine:

• The appropriate sample quantity
• Recommended collection and shipping containers
• Target polymer panel
• Required blanks and controls
• Relevant reporting units
• Whether method development is needed
• Whether complementary testing should be considered

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Frequently Asked Questions

What does pyrolysis-GC/MS measure in a microplastics sample?

Py-GC/MS measures characteristic chemical products generated when polymeric material is thermally decomposed. These compounds are used to identify targeted polymers and determine polymer mass when appropriate calibration and controls are used.

Does Py-GC/MS count individual microplastic particles?

No. Py-GC/MS is primarily a polymer-identification and mass-based technique. It does not independently provide individual particle counts, morphology, or particle-size distribution.

Can Py-GC/MS detect nanoplastics?

Py-GC/MS responds to the total polymer mass introduced into the system and is not inherently limited by the visual size of individual particles. However, the method does not independently demonstrate that the detected material is within a nanoplastic size range. That conclusion depends on sample collection, size fractionation, filtration, preparation, and supporting controls.

Which polymers can CA Analytical test for?

The target panel is customized according to the sample and project. Potential targets include polyethylene, polypropylene, polystyrene, PET, PVC, polycarbonate, polyamides, PMMA, polyurethane, and other polymers for which suitable reference materials, markers, and method performance can be established.

Can you test samples other than water?

Yes. Potential projects may involve product, packaging, pharmaceutical, medical device, food, environmental, air-filter, industrial, or material samples. Non-water matrices generally require a matrix-specific feasibility assessment and may require customized sample preparation and method development.

Is your testing performed according to ASTM D8401-24?

Testing can be developed with reference to ASTM D8401-24 for applicable water matrices. The exact scope, method status, deviations, verification requirements, and reporting language should be established during project planning. Other matrices require demonstration that the method is suitable for the intended application.

How should samples be collected?

Collection requirements vary substantially by matrix and project objective. Contact CA Analytical before collecting samples so that appropriate containers, blanks, sample volumes, handling procedures, and contamination controls can be established.