This data table provided information about the microplastic identification analysis carried out on the samples listed in the data set doi:10.1594/PANGAEA.928575. To guarantee a precise quantification of particles, the sample were analysed entirely by µFT-IR. This procedure requires an aliquoting of the samples in subsamples. The number and the volume of subsamples, in the table depict as % aliquot, were established after calculating the number of particles present in each sample, to avoid an overload of the filter necessary to carry out the spectroscopic measurement. By summing the outcomes of the aliquots of a sample, the total number of MP and polymer type per sample was established.

The first column provides the sample ID, followed by the label of the sampling event during the expedition SO250, the date and time of the sampling, the coordinates and depth. The abbreviations, listed below, mean the following:% aliquot: the percentage of sample volume in the subsample.MP kg-1: The number of microplastic particles is reported as microplastic per Kg sediment.NPol kg-1: the number of polymers detected is reported as polymer typer per Kg sediment.all the polymer types detected are reported in their full name and are reported as the number of particles per Kg sediment.