Key Takeaways & Executive Findings
- •• • Py-GC-MS enables polymer-specific identification and quantification with detection limits down to sub-microgram levels, critical for trace microplastic analysis in environmental samples. • • TGA-DSC provides thermal stability and degradation profiles, allowing estimation of polymer mass loss and additive content, but lacks chemical specificity, necessitating hyphenation with MS. • • TED-GC-MS offers automated, high-throughput analysis with minimal sample preparation, achieving recoveries above 80% for spiked microplastics in complex matrices, as demonstrated in pressurized liquid extraction studies. • • Standardization of pyrolysis protocols and development of reference materials are urgently needed to ensure inter-laboratory comparability and regulatory acceptance.
Abstract
Microplastics, as a class of emerging environmental contaminants, pose global concerns due to their potential ecological and human health impacts. Accurate identification and quantification of microplastics in environmental matrices are essential for assessing their environmental fate and ecological risks. Pyrolysis-based analytical methods, which decompose macromolecules into smaller fragments followed by gas chromatographic separation and mass spectrometric detection, offer high sensitivity and accuracy, making them significant for microplastic analysis. Despite these advantages, their application remains nascent, with limited comprehensive understanding of their applicability across diverse environmental media. This review systematically compares three pyrolysis-based techniques—pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), thermogravimetry-differential scanning calorimetry (TGA-DSC), and thermal extraction-desorption gas chromatography-mass spectrometry (TED-GC-MS)—for microplastic detection in various matrices. The effectiveness of each method is evaluated in terms of sensitivity, selectivity, and matrix compatibility. Critical challenges, including lack of standardized protocols, complex sample pretreatment requirements, and limitations in quantifying mixtures, are identified. Future research directions emphasize the need for standardization, optimization of pretreatment for complex matrices, and integration with complementary techniques such as FTIR and Raman spectroscopy to enhance comprehensive microplastic characterization. This review provides a critical framework for selecting appropriate pyrolysis-based methods and highlights areas requiring further methodological development.
1. Introduction
Conventional microplastic detection methods, such as SEM-EDX, FTIR, and Raman spectroscopy, face critical limitations in environmental analysis. SEM-EDX cannot distinguish plastic from non-plastic particles and is time-consuming, while FTIR and Raman are hindered by fluorescence interference and limited spatial resolution for small particles. These techniques often fail to provide quantitative mass-based data, which is essential for risk assessment. The need for robust, sensitive, and quantitative methods has driven interest in pyrolysis-based techniques, which offer polymer-specific identification and quantification through thermal decomposition and subsequent mass spectrometric analysis.
Pyrolysis-based methods, including Py-GC-MS, TGA-DSC, and TED-GC-MS, address these bottlenecks by enabling direct analysis of microplastics without extensive particle isolation. They provide high sensitivity and accuracy, capable of detecting microplastics in complex environmental matrices such as soil, sediment, and biota. However, their application is still in early stages, with challenges in standardization and matrix effects. This review systematically evaluates these methods, highlighting their strengths and limitations, and proposes future directions to enhance their reliability and applicability in environmental monitoring.
Loading authentic research manuscript (Pages 1–5)...
ZHENG Kexin, WANG Peng, CHEN Mingfeng, HU Yong, ZHOU Lifang, XIE Hongwei, QUAN Changjian, ZHOU Zhen, GAO Xiangjing (2026). Application of Pyrolysis-Based Analytical Methods for Environmental Microplastic Detection. Environmental Chemistry. https://doi.org/10.7524/j.issn.0254-6108.2025041405
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the detection limits of Py-GC-MS for microplastics in environmental samples?
Py-GC-MS can achieve detection limits in the sub-microgram range for common polymers like polyethylene and polypropylene, depending on the sample matrix and pretreatment. For instance, studies using pressurized liquid extraction coupled with Py-GC-MS have reported limits of detection around 0.1 µg for microplastics in sediment samples.
How does TGA-DSC differentiate between polymer types and additives?
TGA-DSC provides thermal degradation profiles (e.g., decomposition temperature and mass loss) that can be characteristic of polymer types, but it lacks chemical specificity. Differentiation is achieved by comparing thermograms with reference materials, and coupling with MS (TGA-MS) allows identification of evolved gases, enabling additive analysis.
What are the main challenges in quantifying microplastics in complex matrices using TED-GC-MS?
TED-GC-MS faces challenges such as matrix effects leading to signal suppression or enhancement, incomplete thermal extraction of polymers, and potential co-elution of interfering compounds. Recovery rates can vary from 70% to 90% depending on the matrix, and rigorous method validation with spiked samples is required.
Can pyrolysis-based methods be standardized for regulatory monitoring?
Standardization is currently limited due to variations in instrumentation, pyrolysis conditions, and data analysis. Efforts are underway to develop reference materials and inter-laboratory comparisons. For regulatory adoption, consensus on calibration strategies, quality control criteria, and reporting units (e.g., mass-based) is essential.
Related Chinese Research & Cross-Citations
Exploring the Potential Molecular Mechanisms of Eight Environmental Pollutants in Lung Adenocarcinoma through Network Toxicology, Machine Learning, and Multi-Omics Analysis
Epidemiological studies have established a significant association between exposure to environmental pollutants (EP) and the risk of lung adenocarcinoma (LUAD). This study integrates network toxicology and multi-omics analysis to elucidate the EP-LUAD molecular regulatory network and identify key regulatory genes, thereby revealing novel mechanisms of environmental carcinogenesis. Transcriptomic data from GEO and TCGA databases yielded 4,971 and 4,488 disease-related targets, respectively. Integration of toxicology databases (TargetNet, Swiss Target Prediction, CTD, SEA) identified 24,860 potential targets for eight common pollutants (SO2, NO, CO, NO2, O3, benzene, toluene, and polycyclic aromatic hydrocarbons). Intersection of these datasets produced 1,536 EP-LUAD common target genes. Protein-protein interaction network analysis identified 247 core targets. Machine learning selected five key genes: AGER, CAV1, CD44, CEP55, and GNB3, which demonstrated robust diagnostic and prognostic efficacy. Their expression correlated with immune cell infiltration, including CD4+ memory T cells and macrophages. Single-cell RNA sequencing revealed epithelial cell-specific expression patterns. Molecular docking confirmed stable pollutant-target binding, with PAH showing highest affinity for CD44 (binding energy −9.32 kcal·mol−1) and GNB3 (−8.32 kcal·mol−1). These findings establish AGER, CAV1, CD44, CEP55, and GNB3 as core molecular mediators of pollution-related LUAD. The high-affinity binding of PAH to CD44 and GNB3 underscores its carcinogenic potential. This study constructs a multi-level regulatory network for EP-LUAD, revealing underlying molecular mechanisms and providing novel potential targets and theoretical basis for early warning and intervention.
Effects of Different Functionalized Nanoplastics on the Transformation of Extracellular Antibiotic Resistance Genes in Aquatic Environments
The rapid dissemination of antibiotic resistance genes (ARGs) in aquatic environments poses serious threats to public health and environmental safety under the 'One Health' framework. Nanoplastics (NPs), as co-occurring pollutants, can exacerbate ARG risks by promoting horizontal gene transfer (HGT), yet the influence of different functional groups on extracellular ARG (eARG) transformation remains unclear. This study investigated the effects of carboxy-modified polystyrene NPs (PS-COOH) and amino-functionalized polystyrene NPs (PS-NH2) compared to unmodified polystyrene NPs (PS) on the transformation of the extracellular resistance plasmid IE-V1955 (carrying an ampicillin resistance gene) into Escherichia coli DH5α. Results showed that PS-COOH exposure promoted plasmid transformation similarly to PS, with effects increasing over 0.1–20 mg·L−1. Low concentrations (0.1–0.5 mg·L−1) of PS-NH2 also enhanced transformation, with stronger effects than PS-COOH at equal doses, whereas high concentrations (1–20 mg·L−1) inhibited it. Mechanistically, PS-COOH (0.1–20 mg·L−1) and low PS-NH2 induced intracellular reactive oxygen species (ROS), increased cell membrane permeability, elevated the protein-to-polysaccharide ratio in extracellular polymeric substances (EPS), and promoted biofilm formation, thereby facilitating transformation. High PS-NH2 concentrations caused excessive ROS leading to cell lysis and formed aggregates with plasmids larger than membrane pores, blocking uptake. These findings provide a theoretical basis for assessing the combined environmental health risks of NPs and ARGs.
Cardiovascular Toxicity Induced by Micro/Nano-Plastics and Its Mechanisms
Micro/nano-plastics (MNPs) are emerging contaminants widely detected in human circulatory systems, including blood, heart, and vascular endothelium, raising concerns about cardiovascular health risks. This systematic review analyzed 61 peer-reviewed studies (2008–2024) to elucidate the cardiotoxic effects and molecular mechanisms of MNPs. Evidence indicates that MNPs exposure elevates risks of atherosclerosis, thrombosis, and arrhythmias through oxidative stress, inflammatory cascades, endothelial dysfunction, and metabolic dysregulation. Notably, co-exposure with persistent organic pollutants (POPs) or heavy metals may produce synergistic or antagonistic effects. Current research relies predominantly on animal and cell models, with critical gaps in low-dose, long-term exposure data and epidemiological evidence. Future studies should optimize experimental designs, integrate metabolomics and epigenetics, and explore transgenerational effects and combined toxicity mechanisms to inform pollution control policies and mitigate cardiovascular risks.
Body Burden of Polybrominated Diphenyl Ethers and Joint Effects on Thyroid Function in a Physical Examination Population in Shenzhen
This study characterized the body burden of polybrominated diphenyl ethers (PBDEs) in a physical examination population in Shenzhen and evaluated its impact on thyroid function. Serum samples from 368 residents were analyzed for eight PBDE congeners using atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS). The median concentration of ∑8PBDEs was 10.2 ng·g⁻¹ lipid weight (lw), ranging from 0.13 to 2089.4 ng·g⁻¹ lw, with BDE-209 predominating (59.7% of total). Multiple linear regression revealed that a 1.7-fold increase in serum BDE-153 was associated with a 0.4% increase in free triiodothyronine (FT3) (P<0.05), while a 1.7-fold increase in BDE-183 was associated with a 0.9% decrease in total triiodothyronine (T3) and a 0.7% decrease in FT3 (P<0.05). Bayesian kernel machine regression (BKMR) indicated a negative correlation between mixed PBDE exposure and thyroid-stimulating hormone (TSH) at high exposure levels. Weighted quantile sum (WQS) regression showed that mixed exposure was associated with decreased T3 levels and T3/FT3 ratio, with BDE-153 and BDE-183 as the primary contributors. These findings suggest that PBDE exposure may adversely affect thyroid function and disrupt thyroid hormone homeostasis, with BDE-183 and BDE-153 playing key roles. This study provides a scientific basis for PBDE health risk assessment and thyroid protection.
Mechanisms of Natural Organic Matter in Regulating Microplastic Aggregation and Transport in Soil-Groundwater Systems: A Review
Microplastics (MPs) are persistent emerging contaminants ubiquitously distributed in soil-groundwater environments, where their aggregation and transport critically govern pollutant fate and ecological risks. Natural organic matter (NOM), a complex assemblage of organic compounds, interacts with MPs and porous media via hydrogen bonding, π-π interactions, hydrophobic effects, and electrostatic binding, thereby modulating MP surface properties and environmental behavior. This review systematically synthesizes the mechanisms by which NOM influences MP aggregation and transport, with emphasis on the distinct roles of humic substances, proteins, and extracellular polymeric substances (EPS), and their synergistic modulation with solution chemistry (pH, ionic strength, ion type). Additionally, NOM accelerates MP aging and alters surface characteristics, consequently impacting transport capacity. Current research limitations are identified, and future directions are proposed to inform MP pollution risk assessment and management strategies. Key findings indicate that NOM generally enhances MP stability and mobility at low ionic strengths, while high ionic strengths may induce aggregation depending on NOM type and ion valence. Humic substances predominantly increase electrostatic repulsion, whereas proteins and EPS can bridge particles, promoting aggregation. Aging processes, accelerated by NOM photochemical activity, increase surface oxygen functionality and hydrophilicity, further altering transport. The review underscores the need for systematic studies under environmentally relevant conditions to predict MP fate accurately.
Neurotoxicity of Carboxyl-Modified Polystyrene Microplastics on Zebrafish at Early Developmental Stage
Carboxyl-modified polystyrene microplastics (PS-COOH) are negatively charged particles formed by surface oxidation and functional group modification of polystyrene microplastics (PS), widely used in biomedical and analytical chemistry. However, studies on their neurotoxic effects on aquatic organisms are scarce. This study employed zebrafish (Danio rerio) as a model organism, exposing embryos to environmentally relevant concentrations (0.1, 1, 10, 100 μg·L−1) of PS and PS-COOH. Neurotoxic effects were assessed by measuring tail coiling frequency at 24 hpf and swimming velocity under alternating light/dark cycles at 120 hpf. Results demonstrated that both PS and PS-COOH induced neurotoxicity, with PS-COOH significantly reducing tail coiling frequency and average swimming speed compared to PS (P<0.05). Exposure to 10 μg·L−1 PS-COOH disrupted neurotransmitter homeostasis, altering levels of acetylcholine (ACh), serotonin (5-HT), and γ-aminobutyric acid (GABA). Transgenic zebrafish Tg(huc:EGFP) fluorescence assays revealed that PS-COOH (0.1–100 μg·L−1) caused damage to central neurons. These findings indicate that PS-COOH exposure impairs cholinergic, serotonergic, and GABAergic neurotransmission, induces neuronal damage, and exerts neurotoxic effects on zebrafish larvae. This study provides a theoretical basis for assessing the ecological and health risks of modified microplastics.