Fluorescence spectra of the dispersions of plastic particles that were prepared as calibration standards in measuring the plastic content of dispersions #2-4. Blue - spectra of initial dispersions, red - spectra after centrifugation at 50,000 g, 1 hour and light blue - spectra of the cuvette with water. Excitation - 450 nm. The insertions are images of vials with initial dispersions, solutions after centrifugation, and water (from left to right), visualized on a UV transilluminator operated at 254 nm. Polymer concentrations: PS - 821, PVC - 518 and PMMA - 311 mg/L. Dibenzylfluorescein - 0.25% from the polymer mass.