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

There is a current gap in sample preparation techniques integrating the separation of microplastics according to their different material types and particle sizes. We describe herein the Bidimensional Dynamic Magnetic Levitation (2D-MagLev) technique, enabling the resolution of mixtures of microplastics sorting them by plastic type and particle size. Separations are carried out in a bespoke flow cell sandwiched between two ring magnets and connected to programmable pumps for flow control.

Magnetism-Assisted Density Gradient Separation of Microplastics.

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 MnCl, enabling the sequential suspension and collection of particles with different densities.

Biphasic Magnetic Levitation to Detect Organic Pollutants on Microplastics.

Microplastics have the potential to adsorb organic pollutants due to their lipophilic nature. Evaluating the distribution of multiple organic pollutants in different types of microplastics coexisting in a sample is a strenuous and challenging analytical task. Here, we report position-dependent microplastic trapping in a biphasic medium comprising a paramagnetic aqueous donor phase containing the mixed microplastics and a diamagnetic organic acceptor phase.

Miniaturized 3D printed solid-phase extraction cartridges with integrated porous frits.

Here we have studied the effect of the thickness and printing orientation using PolyJet 3D printing to fabricate single-material cartridges with built-in porous frits enabling solid-phase extraction (SPE) by packing commercial sorbents. This is achieved by tuning the degree of interpenetration of the building material and the water-soluble support material used in PolyJet 3D printing by modifying the orientation of the print head respective to the frit. SPE cartridges printed at an orientation of 30° with a 150 μm thick integrated frit were selected for the SPE experiments in a compromise between frit permeability to flow and stability to retain commercial sorbents for SPE.