Revista Brasileira de Ciências Ambientais (Jun 2024)
Microplastics on the surface of marine waters of the coast of Santa Catarina (Brazil): identification by stereomicroscope and FTIR-ATR spectrophotometer
Abstract
The oceans are one of the final destinations for the vast majority of plastic waste; in this sense, particles smaller than 5 mm, classified as microplastics (MPs), represent an environmental challenge with global impact on several ecosystems. The work evaluated the presence of MPs in marine waters off the northern coast of Santa Catarina (Brazil), addressing sampling procedures, opening, characterization, and polymer identification. A low-cost equipment developed with easily accessible materials was tested in the sampling, showing excellent results in terms of buoyancy, stability, and mechanical strength. The concentration of MPs obtained in the study was 0.01 MPs per m3. The particles found were analyzed by stereomicroscopy and classified according to morphological aspects in relation to shape into fragments 58,00%, films 25,00%, and lines 17,00%, and regarding the aspect related to color, blue was predominant. The characterization and polymeric identification was performed by Fourier transform infrared spectroscopy coupled to the total attenuated reflectance module (FTIR-ATR). The types of polymers identified were: polyethylene 33,33%; polypropylene 25,00%; butadiene-styrene copolymer 25,00%, and cellulose 16,66%. The work contributed to the evaluation of an area not yet studied in relation to the presence of MPs in marine waters, while at the same time described in detail the methodologies for analyzing microplastics proposed in the specialized literature.
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