Sampling, Identification and Characterization of Microplastics Release from Polypropylene Baby Feeding Bottle during Daily Use
July 24th, 2021
This study detailed a reliable and cost-effective protocol for microplastics collection and detection from the daily use of plastic products.
Microplastics are becoming a global concern due to the potential risk to human health. This study focused on widely used polypropylene-based baby feeding bottles to develop a cost-effective protocol suitable for an MP study of many plastic products. This protocol provides the details of sample preparation, identification, and characterization.
It can substantially benefit future studies of microplastics released from plastic products. Microplastics released during formula preparation. Soak the baby feeding bottle in 95 degrees Celsius deionized water to sterilize the bottle.
To avoid the bottle floating, slightly press it using a stainless steel tweezer to ensure the whole bottle body is immersed in the water. After five minutes, take the bottle out and move it to a clean glass disk to await for air-drying. After air-drying, pour 180 milliliters of 70 degrees Celsius deionized water into the bottle.
Then cover the bottle immediately using a glass Petri dish and place it onto a shaking bed. To stimulate the formula mixing process, shake the bottle at a speed of 180 rpm for 60 seconds. After shaking, move the bottle to a clean glass plate and allow it to cool down.
Sample preparation for microplastics identification and quantification. Membrane filter is critical for microplastics capture, visualization, and detection. We used the gold coated polycarbonate membrane filter to capture microplastics.
Place a piece of membrane filter in the middle of a glass base. Then assemble the glass funnel and stainless steel clamp to fix the membrane filter and connect the glass filter with a vacuum pump after gently shaking the cooled water sample in the baby-feeding bottle. Then transfer a certain amount of water sample to the glass funnel using a glass pipette.
Switch on the vacuum pump to allow the water sample to filter through the membrane filter slowly. After filtering, wash the interior of the glass funnel using deionized water to ensure there are no particles sticking to the funnel. Disconnect the vacuum pump and disassemble the glass filter.
Then, carefully take out the membrane filter using a stainless steel tweezer and move it to a clean cover glass. Store the sample in a clean glass Petri dish immediately. Microplastics identification and quantification.
Carefully take out the sample from the glass Petri dish and place the filter sample in the middle of the Raman sample stage. Choose the representative spots in the membrane filter. Observe and photograph the particles on the surface of the membrane filter using an optical microscope.
Set up the Raman system and test these particles one by one using 532 nanometer excitation laser at 10%intensity. Compare the Raman spectrum obtained to referenced standard spectra. The AFM and Raman spectroscopy are assembled in one system.
Hence switch the system to AFM mode and test the topography of interesting microplastic particles. Microplastics test results. To validate this protocol, the standard polystyrene microplastics spheres were added to DI water and tested using the developed protocol.
The PS microplastics were successfully collected and detected. The particle inside the red box was confirmed as a typical polystyrene microplastic. Following the protocol, the microplastics recovery rate was 92 to 101%Hence, the developed protocol is reliable for the baby-feeding bottle test.
The protocol was used to test microplastics released from eight popular baby feeding bottle products, and found the microplastics released levels ranged from 1.3 million to 16.2 million particles per liter during formula preparation. The 3D topographic image further showed that the surface texture of the released microplastics is rich with nano sized bumps and valleys, which can substantially increase their absorption capacity.Conclusion. The study showed that plastic products that are used daily are very important sources for human microplastic exposure.
The protocol detailed here provides a reliable and cost-effective method for microplastics sample preparation and detection, which can substantially benefit future studies of microplastic release from plastic products.
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Overview
This study presents a detailed, cost-effective protocol for quantifying microplastics (MPs) released from polypropylene-based baby feeding bottles under realistic daily-use conditions. The protocol emphasizes contamination prevention, accurate simulation of real-world scenarios, and robust identification and characterization of MPs using advanced analytical techniques. The method is validated with standard microplastics and applied to commercial products, revealing significant MP release during formula preparation.
Key Study Components
Area of Science
- Environmental Science
- Analytical Chemistry
- Materials Science
Background
- Microplastics are a growing global concern due to potential health risks.
- Plastic products, especially those used for food and beverages, can release significant amounts of MPs during daily use.
- Existing protocols for MP measurement are tailored to environmental samples, not household products.
- There is a need for standardized, realistic protocols to assess MP exposure from consumer plastics.
Purpose of Study
- To develop a reliable and cost-effective protocol for quantifying MPs released from baby feeding bottles.
- To simulate real-world usage scenarios, including high-temperature exposure and formula mixing.
- To prevent contamination during sampling and detection.
- To enable accurate identification and characterization of released MPs.
Methods Used
- Sterilization of bottles in 95°C deionized water, followed by air-drying.
- Simulated formula preparation with 70°C deionized water and mechanical shaking.
- Filtration of water samples through gold-coated polycarbonate membrane filters using a vacuum pump.
- Optical microscopy and Raman spectroscopy for MP identification and chemical analysis.
- Atomic Force Microscopy (AFM) for 3D topography mapping of MPs.
- Validation using standard polystyrene microplastic spheres.
Main Results
- The protocol achieved a recovery rate of 92–101% for standard 2 μm polystyrene MPs.
- Detected MP sizes closely matched the expected standard (around 102.2%).
- Testing of eight commercial baby bottles revealed MP release levels ranging from 1.3 million to 16.2 million particles per liter during formula preparation.
- 3D imaging showed released MPs have nano-sized surface features, potentially increasing their absorption capacity.
Conclusions
- The developed protocol is reliable, reproducible, and cost-effective for MP release studies from plastic products.
- Daily-use plastic products, such as baby feeding bottles, are significant sources of human MP exposure.
- This method can substantially benefit future research on MP contamination and exposure assessment.
Frequently Asked Questions
Executive Industry Relevance
Quantitative assessment of microplastics (MPs) released from consumer-grade polypropylene products is critical for exposure source identification and risk assessment in biopharma and environmental health pipelines. This protocol enables standardized, contamination-controlled sampling and robust analytical characterization, supporting predictive confidence in exposure modeling and material safety evaluation. Reliable MP quantification informs portfolio decisions for materials innovation and regulatory compliance in product development.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables precise quantification of MPs as exposure agents for toxicological pathway interrogation.
- Supports mechanistic de-risking by providing validated data on particle release under real-world conditions.
- Facilitates functional validation of material safety for consumer health applications.
Screening & Assay Development
- Delivers reproducible sample preparation and contamination prevention for downstream analytical workflows.
- Standardizes MP capture and identification using membrane filtration and Raman spectroscopy.
- Enables quantitative outputs for comparative screening of polymer formulations.
Translational & Preclinical Research
- Aligns MP exposure quantification with translational biomarker studies in preclinical models when relevant.
- Provides continuity from material characterization to exposure assessment in risk evaluation pipelines.
- Supports risk-adjusted advancement of safer material alternatives.
Pipeline & Workflow Integration
This protocol integrates into the discovery-to-preclinical continuum for material safety and exposure assessment, supporting both early-stage hypothesis testing and downstream analytical validation.
- Discovery Biology: Enables hypothesis-driven testing of MP release and exposure under simulated use conditions.
- Screening: Provides standardized, reproducible filtration and detection for high-confidence comparative analysis.
- Analytics: Delivers quantitative particle counts and size distribution using validated recovery rates and advanced imaging.
- Translational Research: Supports exposure modeling and risk assessment relevant to human health studies.
- Enterprise Reuse: Protocol is adaptable for diverse plastic products, enabling broad application across R&D portfolios.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in exposure quantification and material safety assessment.
- Operational Value: Standardizes workflows for reproducibility and cross-study comparability.
- Strategic Value: Informs go/no-go decisions for material selection and product design based on exposure risk.
- Portfolio Impact: Enables risk-adjusted prioritization of safer materials and supports regulatory readiness.
Implementation Considerations
- Requires expertise in analytical chemistry and microplastics detection techniques.
- Needs access to membrane filtration, Raman spectroscopy, and AFM instrumentation.
- Demands rigorous contamination control and cross-team protocol standardization.
- Adaptable to various plastic product types with scenario-specific adjustments.
- Limitations include dependency on analytical infrastructure and potential variability in real-world use simulation.
Biopharma FAQs
Chapters in this video
0:00
Introduction
0:32
Microplastics Release During Formula Preparation
1:38
Sample Prepared for Microplastics Identification and Quantification
3:09
Microplastics Identification, Quantification and Characterization using Raman Spectroscopy and AFM
4:07
Microplastics Test Results
5:21
Conclusion
