Excitation 1 ?emission matrix fluorescence spectroscopy combined with MCR-ALS as a tool for the forensic analysis of similar and dissimilar sets of textile fiber extracts

A CAMPIGLIA,; MATHEW REX; MUÑOZ DE LA PEÑA, A; GOICOECHEA H C

Analytical Methods

Royal Society of Chemistry

Año: 2016 vol. 8 p. 8314 - 8321

1759-9660

Trace textile fiber evidence is found at numerous crime scenes and plays an important role in linkinga suspect to the respective scene. In this work, investigations into the fluorescence of fiber dyes andfibers themselves, as well as a methodology for discriminating between fibers using room temperaturefluorescence (RTF) are reported. Initial systematic analysis was conducted on dye standards and extractstaken from fibers colored with the respective dyes of interest. Absorbance, excitation and fluorescencespectra were compared between standards and extracts to determine the optimal area of the fiber toinvestigate dyes, fluorescent impurities or the whole fiber. High performance liquid chromatographyinvestigations were performed to obtain detailed information on the number of dye and fluorescentcomponents present in extracts. Three-way Excitation Emission Matrix (EEM) data were found to give thegreatest amount of spectral information and provide the highest level of discrimination. Successfuldiscrimination between non-similar and similar fibers was achieved with the aid of second order MCRALSchemometric analysis. The level of discrimination obtained via RTF-EEM spectroscopy was sufficientto differentiate among two types of visually indistinguishable fibers and among fibers obtained from twoseparate cloths of the same material and colored with the same dye reagent.