Forensic identification of dyes extracted from textile fibers by liquid chromatography mass spectrometry (LC-MS)

LC-MS is used for the identification of dyes extracted from textile fibers and the utility of the method for forensic trace analysis is demonstrated. The technique is shown to provide a high degree of chemical structural information, making dye identification highly specific in comparison to optical and/or chromatographic methods of dye analysis. A UV-visible absorbance detector, placed in series before the MS detector, facilitates monitoring the elution of dyes in the presence of other non-dye components extracted from colored textile fibers. In this way, dye identification becomes practical, even when a dye standard is not available for comparison. A set of 22 reference dyestuffs and 10 dyes extracted from textile fibers were analyzed to demonstrate the utility of the method. Six of the extracted dyes corresponded to dyes also contained in the set of 22 reference dyestuffs. Reference dyestuffs were not available for four of the extracted dyes. Triethylamine (TEA) was shown to increase the electrospray ionization-mass spectrometry (ESI-MS) response of dyes containing multiple sulfonated groups.     

Sex determination from buccal mucosa and hair root by the combined treatment of quinacrine staining and the fluorescent Feulgen reaction using a single specimen

In order to determine sex using a single specimen, buccal mucosa and hair roots obtained from male and female individuals were used. The specimens were first stained with quinacrine for the detection of the Y-chromatin, and subsequently were stained by the fluorescent Feulgen reaction using acriflavine for the detection of the X-chromatin. In the male specimens, the frequency of fluorescent spots of quinacrine-positive bodies was high, whereas that of acriflavine-positive spots was low. On the other hand, in the female specimens, the frequency of quinacrine-positive spots was very low, while that of the acriflavine-positive spots was high. These specimens were air-dried and were allowed to stand at room temperature for periodical observations. The result was that sex difference was distinguishable for 4 months by the combined treatment method.