Continuous-flow separation and preconcentration of microplastics from natural waters using countercurrent chromatography

• Published in: Talanta (Oxford) 2024-10, Vol.278, p.126504, Article 126504
• Main Authors: Ermolin, Mikhail S., Savonina, Elena Yu, Katasonova, Olesya N., Ivaneev, Alexandr I., Maryutina, Tatiana A., Fedotov, Petr S.
• Format: Article
• Language: English
• Subjects: analytical chemistry; aquatic environment; Countercurrent chromatography; Helianthus annuus; linseed; microplastics; Oil; oils; olives; polyethylene; Preconcentration; rapeseed; Rotating coiled column; Separation; soybeans; vegetables; wastewater; water quality
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2024.126504

Microplastics is known to be ubiquitous in aquatic environment. Quantification of microplastics in natural waters is an important problem of analytical chemistry, the solution of which is needed for the assessment of water quality and potential risks for water inhabitants and consumers. Separation methods play a key role in the correct quantification of microplastics in natural waters. In the present study the applicability of countercurrent chromatography to the continuous-flow separation and preconcentration of microplastics from water samples in rotating coiled column (RCC) using water-oil systems has been demonstrated for the first time. The effect of column rotation speed and mobile phase (water) flow rate on the retention of the stationary (oil) phase in RCC is studied. The retention parameters of 10 vegetable and 2 synthetic oils are determined. Castor, olive, rapeseed, soybean, linseed, sesame, and sunflower oils are found to be applicable to the separation of microplastics from water samples using RCC. Taking as example polyethylene microparticles of different size (40–63, 63–100, and 100–250 μm), the high recovery of microplastics (about 100 %) from aqueous phase into castor and rapeseed oils is shown. The method has been proven to be efficient for the separation of microplastics from simulated fresh and sea natural waters. It may be perspective not only for the quantification of microplastics in natural waters but as well as for the purification of wastewaters containing microplastics. [Display omitted] •Microplastics are separated from waters by countercurrent chromatography.•Behaviour of stationary (oil) phase in rotating coiled column (RCC) is studied.•Retention parameters of 10 vegetable and 2 synthetic oils in RCC are determined.•A series of oils applicable to separation of microplastics from water are chosen.•100 % recovery of polyethylene from fresh and sea waters into oil phase is shown.