You have full access to this open access article. The identification of microplastics becomes increasingly challenging with decreasing particle size and increasing sample heterogeneity. The analysis of microplastic samples by Fourier transform infrared FTIR spectroscopy is a versatile, bias-free tool to succeed at this task. In this study, we provide an adaptable reference database, which can be applied to single-particle identification as well as methods like chemical imaging based on FTIR microscopy.
The large datasets generated by chemical imaging can be further investigated by automated analysis, which does, however, require a carefully designed database. The hereby generated database entries were optimized for the automated analysis software with defined reference datasets. The design was further tested for its customizability with additional entries. The final reference database was extensively tested on reference datasets and environmental samples. Data quality by means of correct particle identification and depiction significantly increased compared to that of previous databases, proving the applicability of the concept and highlighting the importance of this work.
Our novel database provides a reference point for data comparison with future and previous microplastic studies that are based on different databases.
The pollution of aquatic systems with small plastic particles called microplastics MP [ 1 ] is an emerging topic in environmental and analytical science [ 2 , 3 ].
Two introduction pathways for MP into the environment are possible. The first is primary MP, to which the use and disposal of microbeads in cosmetic and cleaning products largely contribute [ 5 ].
