Identification of Dyes on Single Textile Fibers by HPLC-DAD-MS

Abstract

An HPLC-DAD-MS method is described to analyze textile dyes in different dye classes (reactive, basic, acid, direct, disperse). The described method is sensitive enough to analyze single fibers with a length of a few millimeters or less, which makes it suitable for forensic analyses. The current paper describes the information content of the acquired data as well as the results of a validation study, in which the repeatability, specificity, and limit of detection of the method were assessed by repeated measurements of nine different dyes in the mentioned dye classes. The mass accuracy (deviation generally <2 ppm) and absorbance spectra were found to be highly stable in several measurements over a period of 8 weeks. Deviation in retention times were observed and attributed to small experimental effects and a precolumn blockage. The results show that dye analysis is possible for most fibers with a minimum length of one or a few millimeters.

Forensic comparison of synthetic fibers

“…The method is sensitive enough to analyze single textile fibers of a length of few millimeters or less, which makes it suitable for forensic analysis. [92] In this study, the authors presented the application and validation of a highly sensitive chromatographic method, which allows the identification of most types of textile dyes encountered in case work.…”

“…11). [92] Single textile fiber dye identification is also carried out by excitation-emission luminescence spectral cluster analysis. No dye extraction from the fibers is required for this analysis.…”

“…Plots a, c, e, and g present absorbance chromatograms extracted by monitoring the light absorption at a single wavelength (black curves) and mass chromatograms extracted by monitoring the response at a single m/z value (gray curves). [92] Figure 12. Normalized emission (A and C) and absorption spectra (B and D) of fiber dyes used for the identification of single fibers.…”

“…Very recently, an HPLC–DAD–MS method has been used for the analysis of fiber dyes of different classes, such as neutral, positively charged, and negatively charged dyes; dyes with single charges; dyes with multiple charges; hydrophilic and hydrophobic dyes; and dyes in a wide range of size and molecular mass in a single analytical run. The method is sensitive enough to analyze single textile fibers of a length of few millimeters or less, which makes it suitable for forensic analysis . In this study, the authors presented the application and validation of a highly sensitive chromatographic method, which allows the identification of most types of textile dyes encountered in case work.…”

Raman spectrometry as a screening tool for solvent-extracted azo dyes from polyester-based textile fibres

“…In general, analytical approaches include an extraction stage using low polarity solvents, such as chlorobenzene, methanol, dimethylsulfooxide, acetonitrile and dimethylformamide [15,16]. HPLC has been widely deployed for molecular separation, particularly with UV-Vis or fluorescence detection systems [4,17], due to the abundant chromophores usually present in the azo pigments, although hyphenated mass spectrometry detectors have also been used [15,[18][19][20]. Minimally invasive analyses with vibrational spectroscopy techniques such as Raman scattering have been reported [21][22][23][24][25], including applications in the field of modern art [21,25,26].…”