LAUSR

Abstract Polyester fibers are one of the most abundantly produced type of fibers worldwide, second in amount only to cotton fibers, and the disperse dyes are most commonly used to dye them. Therefore, single polyester fibers are frequently assessed as evidence in forensic laboratories. However, until now, only a narrow group of chromatographic methods has been developed for the purposes of such research. In this study, two HPLC-DAD methods and one UPLC-QTOF-MS method for identifying the same polyester fibers dyed by nine commercially available disperse dyes were developed and validated. The dyes gave three types of coloring: red, yellow-green and light gray. Different procedures were tested for isolating the dyes from single fibers. The application of chlorobenzene at 100 °C for 60 min was found to be optimal. The validation data and the results of the analysis of 1 mm thread extracts confirmed the usefulness of the proposed methods for such analyses.