Single fiber identification with nondestructive excitation-emission spectral cluster analysis

Identification methods for single textile fibers are in demand for forensic applications, and nondestructive methods with minimal pretreatment have the greatest potential for utility. Excitation-emission luminescence data provide a three-dimensional matrix for comparison of single-fiber dyes, and these data are enhanced by principal component analysis and comparison of fibers using a statistical figure of merit. No dye extraction methods are required to sample the spectra from a single fiber. This approach has been applied to the analysis of single fibers to compare closely matched dye pairs, acid blue (AB) 25 and 41 and direct blue (DB) 1 and 53. In all cases, the accuracy of fiber identification was high and no false positive identifications were made.