Automated extraction of direct, reactive, and vat dyes from cellulosic fibers for forensic analysis by capillary electrophoresis
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Systematic designed experiments were employed to find the optimum conditions for extraction of direct, reactive, and vat dyes from cotton fibers prior to forensic characterization. Automated microextractions were coupled with measurements of extraction efficiencies on a microplate reader UV–visible spectrophotometer to enable rapid screening of extraction efficiency as a function of solvent composition. Solvent extraction conditions were also developed to be compatible with subsequent forensic characterization of extracted dyes by capillary electrophoresis with UV–visible diode array detection. The capillary electrophoresis electrolyte successfully used in this work consists of 5 mM ammonium acetate in 40:60 acetonitrile–water at pH 9.3, with the addition of sodium dithionite reducing agent to facilitate analysis of vat dyes. The ultimate goal of these research efforts is enhanced discrimination of trace fiber evidence by analysis of extracted dyes.
KeywordsForensic analysis Cotton fibers Extraction of direct, reactive and vat dyes Capillary electrophoresis
This research was supported under a contract award from the Counterterrorism and Forensic Science Research unit of the Federal Bureau of Investigation’s Laboratory Division. Points of view in this document are those of the authors and do not necessarily represent the official position of the Federal Bureau of Investigation.
- 1.Palenik S (1999) In: Robertson J, Grieve M (eds) Forensic examination of fibres, 2nd edn. Taylor & Francis, London, pp 364–378Google Scholar
- 2.Stoeffler SF (1996) J Forensic Sci 41:297–299Google Scholar
- 3.Rendle DF, Wiggins KG (1995) Forensic analysis of textile fibre dyes. Rev Prog Color Relat Top 25:29–34Google Scholar
- 4.Shore J (2002) Colorants and auxiliaries, vol. 1, 2nd edn. Society of Dyers and Colourists, West Yorkshire, England, pp 18–23Google Scholar
- 10.Smith W (2005) Experimental design for formulation. Cambridge University Press, New YorkGoogle Scholar
- 11.Deming SN, Morgan SL (1993) Experimental design: a chemometric approach, 2nd edn. Elsevier Science, AmsterdamGoogle Scholar
- 12.Deming SN, Morgan SL (1979) Clin Chem 25:840–855Google Scholar
- 15.Nalankilli G (1997) Colourage 44:33–39Google Scholar