Dušan Materić 1,*, Rupert Holzinger1, Helge Niemann2,3 1 Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands 2 NIOZ Royal Netherlands Institute for Sea Research, Landsdiep 4, 1797 SZ 't Horntje (Texel), the Netherlands 3Department of Earth Sciences, Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands *Correspondence: d.materic@uu.nl This is the repository of the supplementary, data and it contains: 1. Raw .h5 data files as the original output of TD-PTR-MS for the direct measurement (Site A); 2. Raw .h5 data files as the original output of TD-PTR-MS for the cascade filtering measurements (Site B); 3. Raw .h5 data files as the original output of TD-PTR-MS for the calibration measurements (PS and PET); The folder also contains processing files as the output of PTRwid software used; 4. PTRwid version of software we used for mass spectra and molar ratio extraction; 5. PTRwid associated parameters file that contains the parameters for mass spectra extraction (including the ToF transmissions) 6. Nanoplastics Fingerprint scripts used for the experiments; All “massLibr*” files contain the mass spectra of virgin plastics with molar ratio (ppb) value for each ion detected in the plastics vapours (3 decimal point precision of m/z). The script files were written in PYTHON (compatible with PYTHON 2 and 3 - all versions). “DataFlip.py” is used for formatting the data into the matrix acceptable for the fingerprinting script. “FngClass.py” and “funFunctions.py” are supporting classes used for the main scripts. matchingTest.py is a main script used for comparing a sample mass spectrum to the one from the plastics library (e.g. for PET use “massLibrPET.csv”). matchingLoopQ3.py is a main script used for comparing all the samples with all the plastics from the library (“massLibr*” files). 7. Data analysis of mass spectra: subtraction and limit of detection calculation for “Direct WS*” measurement (Site A)