As the plastic production has been rising since the last five decades, so does the concern for the occurrence of microplastic particles (<5 mm)in the marine environment during the past years. But still by now the extent of this microplastic pollution of coastal waters and the open ocean remains unclear. Since monitoring the abundance of microplastics in the marine environment is requested by the Marine Strategy Framework Directive (MSFD) standardized and reliable methods forthe detection of microplastics are urgently needed. Studies differ mainly in their purification methods, aiming to reduce biogenic material in environmental samples without altering the plastic polymers to facilitate a clear assignment of the microplastics. In the present and ongoing study the purification method consists of a treatment with technical enzymes and detergents to reduce the use of oxidants and avoid the use of strong acids as well as the subsequent identification and quantification of microplastics applying Focal Plane Array (FPA)-based μFourier Transform Infrared (μFT-IR) spectroscopy.