Application of mist to fingermark detection: Misting with high-boiling-point liquid containing p-dimethylaminocinnamaldehyde and cyanoacrylate.

In order to detect latent fingerprints that could be damaged by liquid or powder reagents, non-destructive processes such as gaseous reagents have been developed. In this report, we propose the use of fine mist generated when hot vapor of high-boiling-point liquids is rapidly cooled by surrounding air for fingermark detection. Octyl acetate (OA), 2-phenoxyethanol (2PE), and methyl decanoate (MD) were found to efficiently produce mist when heated to 230°C. By combining these liquids with p-dimethylaminocinnamaldehyde (DMAC) and cyanoacrylate (CN), our team demonstrated effective fluorescence staining of cyano-treated fingermarks using DMAC/OA misting or DMAC/2PE misting, and one-step fluorescence detection of latent fingermarks without cyanoacrylate treatment using DMAC/OA/CN misting or DMAC/MD/CN misting. Fingermark fluorescence was efficiently observed by excitation with a blue LED light (max. wavelength 470 nm) equipped with an interference filter and passing through a 520 nm long-pass filter. We successfully obtained fluorescent images from fingermarks on several substrate materials using the developed misting method.

Systematic In Vitro Metabolic Profiling of the OXIZID Synthetic Cannabinoids BZO-4en-POXIZID, BZO-POXIZID, 5F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID.

A new class of synthetic cannabinoids termed OXIZIDs has recently emerged on the recreational drug market. In order to continue the detection of new drugs in biological specimens, the identification of metabolites is essential. The aim of this study was to elucidate the metabolites of BZO-4en-POXIZID produced in human liver microsomes (HLMs) and human hepatocyte incubations and to compare the results with closely related analogs using the same experimental setup. Each drug was incubated for 1 h in HLM and BZO-4en-POXIZID was also incubated in human hepatocytes for up to 3 h. Subsequently, the incubates were analyzed by liquid chromatography-high-resolution mass spectrometry. BZO-4en-POXIZID metabolites were obtained in the incubation with HLMs and human hepatocytes, via the metabolic pathways of dihydrodiol formation, hydroxylation, reduction of the alkene bond and glucuronidation. The major metabolic pathway was found to be dihydrodiol formation at the pentenyl tail moiety. BZO-POXIZID, 5 F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID underwent similar metabolism to those reported in the literature, via the metabolic pathways of N-dealkylation, hydroxylation, ketone formation and oxidative defluorination (to alcohol or carboxylic acid). The results suggest that OXIZIDs are mainly metabolized at the N-alkyl moiety and the major metabolic pathways are hydroxylation when the N-alkyl moiety is a simple hydrocarbon, whereas functional-group-specific pathways (dihydrodiol formation and oxidative defluorination) are preferred when the moiety contains specific functional groups (alkene or fluoro), as has been observed for other synthetic cannabinoids. The major metabolites generated via these major metabolic pathways should serve as useful analytical targets for urine analysis. Furthermore, the higher abundance of glucuronidated metabolite suggests that enzymatic hydrolysis of glucuronides may be necessary for urine analysis to increase phase I metabolite concentration and improve detection.

Forensic Discrimination of Drug Powder Based on Drug Mixing Condition Determined Using Micro Fourier Transform Infrared Spectroscopy.

The quantitative evaluation of the drug mixing condition was conducted for application in the forensic discrimination of drug powders using micro Fourier transform infrared (FT-IR) spectroscopy. Bromhexine hydrochloride (BHCl) and p-hydroxybenzoic acid (PHBA) were used as the simulated drug and additive, respectively. Equal masses of two chemicals were (1) simply mixed, (2) homogenized using agate mortar, or (3) dissolved in methanol and dried, and then (4) homogenized using agate mortar. The mixed powders dispersed on BaF2 plates were subjected to mapping analysis of micro FT-IR spectroscopy using synchrotron radiation (SR) or globar light in transmission mode with aperture sizes of 2.5 x 2.5 and 10 x 10µm2, and x-y scanning steps of 2.5 and 10 µm, respectively. The areas of the vibration bands specific to BHCl (C-N bending) and PHBA (C=O stretching) were converted to the molar contents (CBHCl, CPHBA), and the relative content ratio (RCR: CPHBA/[CBHCl + CPHBA]) was used as one mixing parameter. The resulting two-dimensional distribution map provided the relative spatial localizations of the two species, and frequency histograms with a horizontal axis of RCR were plotted to evaluate the RCR distribution. The percentage frequency of the extreme value in which RCR was 0 or 1 (%EV) was used as one mixing index. After excluding the extreme values, the coefficient of variation (CV) of the RCR distribution was used as another mixing index. The differentiation among four mixing modes could be evaluated from the standpoint of %EV and CV, and the discrimination capacity by SR instrument was superior to that by globe light instrument.

Effects of Machine Washing on the Chromatography Parameters of Polyester Fiber Gel Permeation.

Fiber examination is frequently performed in forensics, and gel permeation chromatography (GPC) is one candidate method for discriminating polyester fibers. Here, the effects of machine washing on weight-average molecular weight (M w), polydispersity index (PDI), and the percentage peak area of cyclic ethylene terephthalate trimer (PPAL) of commercial polyester shirts and manufactured poly(ethylene terephthalate) (PET) yarns were investigated using GPC. GPC was performed using a 1,1,1,3,3,3-hexafluoro-propan-2-ol polymer solubilizer, styrene-divinylbenzene copolymer GPC columns, a chloroform mobile phase, and a 254 nm absorbance monitor. The statistical change in the polyester fibers during machine washing was evaluated by comparing three GPC parameters of the same fiber samples before and after machine washing. Among the commercial polyester shirts examined, the GPC parameters changed significantly after machine washing with a considerable PPAL decrease. In contrast, the GPC parameters of manufactured PET yarns changed significantly with a moderate increase in M w. This work elucidates the change on GPC parameters of polyester fibers by machine washing.

Vapor-phase staining of cyanoacrylate-fumed latent fingerprints using p-dimethylaminobenzaldehyde.

Contrasting or enhancing of cyanoacrylate ester-fumed latent fingerprints deposited on solvent-sensitive materials such as oil marker writings and rough surface materials such as unglazed earthenware is not easy by conventional dye solutions dipping or dye powder dusting. In this study, a new vapor-phase staining method using p-dimethylaminobenzaldehyde (DMAB) is proposed for staining such materials. DMAB has high volatility and selective absorbability to cyanoacrylate-fumed fingerprints, so that cyanoacrylate-treated samples can be easily stained by leaving them simply in a closed container along with DMAB crystals for 48-96 h at room temperature or in conjunction with the use of mild heating. The stained fingerprint could be excited by UV irradiation (365 nm), and the fluorescent fingerprint was photographed through a UV cut-off filter (420 nm). The new method achieved minimally destructive fluorescent staining for the solvent-sensitive samples and the rough surfaced samples.

Detection of pretreated fingerprint fluorescence using an LED-based excitation system.

Optimization of a light emitting diode (LED)-based excitation system for the detection of pretreated fingerprint fluorescence is described. Fluorescent ridges can usually be excited by irradiation with forensic light sources such as xenon arc lamps or quartz-halogen lamps with high-power output and suitable filters. However, they are too expensive for many crime laboratories in smaller organizations. We concentrated on LEDs which have advantages over conventional light sources in that they are simpler and of lower cost, but the power output and quality of each individual LED unit is not sufficient for the detection of weak fluorescent ridges. To resolve this subject, blue and green LED arrays composed of ninety LED units were adopted and suitable low pass filters for them were designed. An experimental system, consisting of blue and green LED arrays with the suitable low pass filters for illumination, high pass filters for viewing, a digital camera and a computer, was tested. The fluorescent images of cyanoacrylate ester fumed/rhodamine 6G stained fingerprint on white polyethylene sheet and weak fluorescent ridges of ninhydrin/indium chloride treated fingerprint on white paper were successfully detected and photographed. It was shown that the improvement of LED beam in intensity and quality can compensate the disadvantages, resulting in well-contrasted images.

Lower limits of detection of synchrotron radiation high-energy X-ray fluorescence spectrometry and its possibility for the forensic application for discrimination of glass fragments.

Synchrotron radiation high-energy X-ray fluorescence (SR-XRF) analysis utilizing 75.5keV X-ray radiation from beam-line BL37XU at Super Photon Ring 8GeV (SPring-8), a third-generation synchrotron facility, was found to have advantages for forensic discrimination of glass samples. The lower limits of detection (LLD) for calibration curves were at the picogram level for Ba, Ce, and Sm and at the 10pg level for Sr, Zr, Sn, and Hf. The spectrum of NIST SRM 612 glass reference material demonstrated K-line peaks of 31 elements including rare-earth elements, and the relative standard deviations (R.S.D.) of all the measured elements except Ca were less than 9.7%. Fragments of collected sheet glass were used as samples for investigating the application of this technique to forensic analysis. Several trace elements such as Pb, Rb, Sr, Zr, La, Ce, and Hf were detected in the spectra of the samples, and these elements could be used as indexes to characterize the glass samples. But the "lower limits of detection (LLD)" of each element were not examined enough. In this report, these limits by synchrotron radiation X-ray spectrometry were clarified. By these results, this technique should provide an effective approach to the nondestructive discrimination of small glass fragments in the field of forensic science.

Forensic discrimination of sheet glass by a refractive-index measurement and elemental analysis with synchrotron radiation X-ray fluorescence spectrometry.

Measurements of the refractive index (RI) and elemental analysis using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) were applied to the forensic discrimination of sheet-glass samples from different origins. The refractive index was calculated from the matching temperature at which the glass fragments became invisible in silicone oil. Fragments smaller than 1 mm in maximum diameter were taken from each of 11 sheet glasses and subjected to analysis by SR-XRF. The XRF spectrum of these samples indicated that a comparison of 6 elements (Ca, Fe, Sr, Zr, Ba and Ce) was useful for the discrimination of sheet glasses. Cluster analysis was performed using 33 sets of SR-XRF data obtained by triplicate measurements for the 11 glasses. Comparing 528 pairs among 33 samples, 515 pairs could be correctly discriminated. The number of indistinguishable pairs could be reduced from 36 to 4 by comparing the SR-XRF data. Elemental analysis by SR-XRF could provide small glass fragments with a more evidential value than the solely measurement of only RI, through a significant improvement of the discrimination capability.