Assessing the level of airborne polystyrene microplastics using thermogravimetry-mass spectrometry: Results for an agricultural area

Highlights: • PM₁₀ airborne polystyrene microplastics were quantified by TGA-MS. • PS-MPs were found close to 36 ng m⁻³ in the atmosphere of the studied area. • Main potential source of contamination is related to agricultural activities. The global consumption of plastic is increasing year by year. The usage of plastic materials may generate small plastic fragments known as microplastics (MPs) which affect the quality of the air we breathe. In this study, a procedure based on thermogravimetry coupled to mass spectrometry (TGA-MS) has been developed to quantify polystyrene (PS) microplastics found in the atmosphere nearby an agricultural area. The quantification of PM₁₀ fractions of airborne PS microplastics has been scarcely studied. For this purpose, around 50 mg of the fiberglass filters used for the airborne sample collection were pyrolyzed on the TGA instrument (40–800 °C) at 10 °C min⁻¹. At the same time, sample mass loss and MS signal intensity of typical PS pyrolysis compounds were recorded. Limits of detection and quantification were 7.7 and 25.8 ng m⁻³, respectively. PS microplastic has been found in the studied atmosphere area at an average of 35.97 ng m⁻³, the potential contamination source being mainly related to agricultural activities. This works shows the potential of the hyphenated TGA-MS methodology as a complementary technique for microplastics characterization.