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Analysis of Fiber Dyes by Liquid Chromatography Mass Spectrometry (LC-MS) with Electrospray Ionization: Discriminating Between Dyes with Indistinguishable UV-Visable Absorption Spectra

NCJ Number
Barry G. Fookes, Min Huang, Rachel Russo, Michael E. Sigman
Date Published
May 2005
9 pages
This study examined the utility of Liquid chromatography mass spectrometry (LC-MS) in discriminating between sets of textile dyes that are indistinguishable by UV/visible spectroscopic methods.
An important component of forensic fiber analysis involves dye identification and comparison. UV/visible-based approaches to dye analysis are frequently used yet they are unable to distinguish between two structurally similar dyes. The current study used LC-MS to analyze seven pairs of commercial dyes that have similar UV/visible absorption profiles and absorption maxima within 5 nm. All seven pairs were examined by UV/visible spectroscopy and by LC-MS. Two pairs of cotton fibers that were indistinguishable with UV/visible spectroscopy were differentiated by LC-MS. The findings suggest the utility of using LC-MS for distinguishing between known and questioned fibers in cases where the dyes are different at the molecular level. If LC-MS also fails to distinguish fibers based on their dye content, it is recommended that the analysis be extended to the use of LC-MS/MS or MS/MS of the extracted dye mixture. Figures, references

Date Published: May 1, 2005