0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Detection Methods Environmental Sources Sign in to save

Magnetism-Assisted Density Gradient Separation of Microplastics

Analytical Chemistry 2022 13 citations ? Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count. Score: 35 ? 0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Xinpeng Ren, Michael C. Breadmore, Fernando Maya

Summary

Researchers developed a magnetism-assisted density gradient separation method using a specialized cell connected to a gradient pump and positioned between opposing neodymium magnets, through which increasing MnCl2 concentration gradients sequentially suspend and collect different microplastic types by density for efficient separation from complex particle mixtures.

Polymers
Study Type Environmental

A versatile method for the efficient separation of different types of microplastics from particle mixtures is presented. Magnetism-assisted density gradient separation (Mag-DG-Sep) relies on a bespoke separation cell connected to a gradient pump and located between two like-pole-facing neodymium magnets. In Mag-DG-Sep, particle mixtures initially sunk in water are subjected to a gradient of increasing concentration of MnCl2, enabling the sequential suspension and collection of particles with different densities. The suspension process is assisted by the paramagnetism of the MnCl2 solution placed between the two magnets, which contributes to focusing the ascending particles from the bottom of the separation cell to the outlet, thus enhancing the resolution of the separation process. To demonstrate the concept, a mixture of polyethylene (PE) polymer particles with a similar size range (180-212 μm) but different densities (ca. 0.98, 1.025, 1.08, and 1.35 g cm-3) was selectively separated in a single Mag-DG-Sep run. These particles were also efficiently separated when mixed with other types of particles, such as glass or soil. A generic linear MnCl2 gradient can be directly applied for sample screening covering a broad range of densities (0.98-2.20 g cm-3), while steps can be introduced in the gradient, increasing the separation resolution of particles with close densities (1.025-1.08 g cm-3). As a proof-of-concept application, Mag-DG-Sep facilitated sample preparation of microplastics present in a soil sample prior to their examination by attenuated total reflection Fourier-transform infrared spectroscopy.

Sign in to start a discussion.

More Papers Like This

Article Tier 2

Bidimensional Dynamic Magnetic Levitation: Sequential Separation of Microplastics by Density and Size

Researchers developed a two-dimensional dynamic magnetic levitation technique that simultaneously separates microplastics by both material density and particle size in a single step. The 2D-MagLev method addresses a key gap in microplastic sample preparation by resolving mixtures of plastics that differ in both polymer type and particle dimensions.

Article Tier 2

Non-Destructive Extraction and Separation of Nano- and Microplastics from Environmental Samples by Density Gradient Ultracentrifugation

Researchers developed a non-destructive method using density gradient ultracentrifugation to extract and separate different types of nano- and microplastics from environmental samples. The study demonstrates that this approach can effectively separate various plastic polymer types from complex environmental matrices based on their density differences, offering a promising new tool for microplastic analysis.

Article Tier 2

Microplastic Collection With Ultra-High Magnetic Field Magnet by Magnetic Separation

Ultra-high magnetic field magnets were evaluated for collecting microplastics from ocean water through magnetic separation, offering a high-throughput processing approach that could complement existing microplastic cleanup technologies targeting the SDG goal of reducing ocean pollution.

Article Tier 2

Density-Based Multi-Stage Flotation Sorting of Microplastics in Beach Sand

Researchers developed a density-based multi-stage flotation sorting method for separating microplastics from beach sand, achieving high separation efficiency across multiple polymer types with different densities using sequential salt solutions of increasing concentration.

Article Tier 2

A novel approach to extract, purify, and fractionate microplastics from environmental matrices by isopycnic ultracentrifugation

Researchers developed a novel isopycnic ultracentrifugation method for simultaneously extracting and fractionating microplastics from complex environmental matrices such as soil, demonstrating that diffusion-based density gradients enable separation of mixed polymer types according to their specific buoyant densities, overcoming limitations of conventional saturated salt density extraction.

Share this paper