Assessment of multiclass organic pollutants in microplastics from beaches of Tenerife (Canary Islands, Spain)

• Polyethylene microplastics were analysed to assess multiclass organic pollutants. • The methodology exhibited good performance, with high recoveries and low LOQs. • Three beaches of Tenerife (Canary Islands, Spain) were monitored for 9 months. • Triclosan, BPA, TPP, isoamyl p-methoxycinnamate and oxybenzone were found. Microplastics pose a substantial environmental and health threat due to their ability to retain and concentrate pollutants, thereby intensifying their impact on ecosystems and human health. To address the presence of pollutants in microplastics, a vortex-assisted extraction method was expanded and validated to assess 36 multiclass organic pollutants in weathered polyethylene microplastics, using ultra-high performance liquid chromatography coupled to tandem mass spectrometry for their determination. The method demonstrated consistent performance with absolute recoveries mostly ranging between 70 % and 120 % and relative standard deviations below 20 %. Matrix-effect studies were conducted showing clear differences between pristine and weathered microplastics, with this effect higher in the latter. These results highlight the importance of avoiding the extrapolation of validation results between polymers with different degrees of aging. Overall, low limits of quantification of the method were achieved for all pollutants, with values between 1.6 and 22.6 ng/g. An in-depth analysis of the presence of pollutants in microplastics from three beaches of Tenerife, Canary Islands, Spain, was carried out. Remarkably, results revealed that 27.8 % of the samples contained quantifiable amounts of pollutants, including phenols (bisphenol A), UV filters (isoamyl p -methoxycinnamate, and oxybenzone), antibacterial agents (triclosan), and organophosphate esters (triphenyl phosphate), with concentrations ranging from 9.93 to 78.7 ng/g. These findings emphasize the accumulation of harmful compounds in microplastics and underscore the need for effective monitoring, as they may serve as future sources of exposure to dangerous pollutants.