The Identification of Cotton Fibers Dyed with Reactive Dyes for Forensic Purposes

Abstract

Some of the most common microtraces that are currently collected at crime scenes are fragments of single fibers. The perpetrator leaves them at a crime scene or takes them away, for example, on their clothing or body. In turn, the microscopic dimensions of such traces mean that the perpetrator does not notice them and therefore usually does not take action to remove them. Cotton and polyester fibers dyed by reactive and dispersion dyes, respectively, are very popular within clothing products, and they are hidden among microtraces at the scene of a crime. In our recently published review paper, we summarized the possibilities for the identification of disperse dyes of polyester fibers for forensic purposes. In this review, we are concerned with cotton fibers dyed with reactive dyes. Cotton fibers are natural ones that cannot easily be distinguished on the basis of morphological features. Consequently, their color and consequently the dye composition are often their only characteristics. The presented methods for the identification of reactive dyes could be very interesting not only for forensic laboratories, but also for scientists working in food, cosmetics or pharmaceutical/medical sciences.

Numerical Simulation of Dyeing Process of Cotton with Natural Dye

“…This code used a generalized coordinate system to facilitate the application of boundary conditions to different cone geometries. The simulation demonstrates that the inclusion of the dispersion term in the dyeing model improves the simulation dyeing process results in dye absorption [15].…”

“…The concentration in the cotton fiber on the mesoscale has a behavior that accurately indicates the stages of the cotton dyeing process. The first stage, which is an interval from 0 to 1200 s, shows the concentration of the dye in the cotton fiber influenced only by diffusive phenomena, where only the adsorption of the dye in the cotton fibers occurs, as explained by Śmigiel-Kami ńska et al [15]. Additionally, due to the addition of salt (NaCl), forming an electrolytic solution, solvation of the dye is caused, preventing an unwanted reaction between the dye and water (hydrolysis).…”

Innovative Vibrational Spectroscopy Research for Forensic Application

“…S ́migiel-Kaminśka et al published a useful overview of the identification of dyed cotton fibers and dyes. 77 They recommended extraction and analytical procedures, discussed each method available, and suggested specific testing parameters. This work primarily focused on chromatography, but spectroscopic techniques were also highlighted.…”

“…Raman spectroscopy has been shown to be a valuable technique to identify and analyze dying agents. Śmigiel-Kamińska et al published a useful overview of the identification of dyed cotton fibers and dyes . They recommended extraction and analytical procedures, discussed each method available, and suggested specific testing parameters.…”

Adsorption of BEZAKTIV BLAU V3-R and BEZAKTIV BLAU S-2R reactive dyes onto rice husk modified by the circular economy concept

“…Depending on their chemical constitution, reactive dyes could be monochlorotriazine, dichlorotriazine, vinyl sulfone, and heterocyclic halogen-containing dyes. Based on the temperature required for dyeing, they can be cold, medium, or hot brands (Śmigiel-Kamińska et al 2020). These dyes however have a few disadvantages.…”