Currently, there is a significant demand in forensic toxicology for biomarkers of cannabis exposure that, unlike ∆-tetrahydrocannabinol, can reliably indicate time and frequency of use, be sampled with relative ease, and correlate with impairment. Oral fluid (OF) and exhaled breath condensate (EBC) are alternative, non-invasive sample matrices that hold promise for identifying cannabis exposure biomarkers. OF, produced by salivary glands, is increasingly utilized in drug screening due to its non-invasive collection and is being explored as an alternative matrix for cannabinoid analysis.
View Article and Find Full Text PDFCompared with other racial/ethnic groups in the United States (US), American Indians/Alaska Natives have one of the fastest climbing rates of drug overdose deaths involving stimulants. Validating the substances self-reported by Indigenous people who use injection drugs (IPWIDs) can present logistical and cultural challenges. While the collection of biospecimens (e.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2022
Aptamers are promising biorecognition elements for sensors. However, aptamer-based assays often lack the requisite levels of sensitivity and/or selectivity because they typically employ structure-switching aptamers with attenuated affinity and/or utilize reporters that require aptamer labeling or which are susceptible to false positives. Dye-displacement assays offer a label-free, sensitive means for overcoming these issues, wherein target binding liberates a dye that is complexed with the aptamer, producing an optical readout.
View Article and Find Full Text PDFThe class of novel psychoactive substances known as synthetic cannabinoids (SC) includes illicit compounds that are sprayed on plant material and smoked or sold as liquids to be vaporized in e-cigarettes. In toxicological analysis of SC, fast analytical methods are needed for the detection and confirmation of parent drugs and metabolites at very low levels. While various analytical methods have been developed for SC in blood and urine, few are available for alternative matrices such as oral fluid (OF).
View Article and Find Full Text PDFMass spectrometry-based DNA adductomics is an emerging approach for the human biomonitoring of hazardous chemicals. A mass spectral database of DNA adducts will be created for the scientific community to investigate the associations between chemical exposures, DNA damage, and disease risk.
View Article and Find Full Text PDFA novel phenyl modified PDMS (PhPDMS) sol-gel adsorption phase was developed for use with the capillary microextraction of volatiles (CMV) device, and determined to provide significant enhancement in BTEX recoveries when sampling trace (ng) amounts of these volatiles at ambient conditions. The previously reported reusable PDMS-CMV device has been demonstrated to rapidly and efficiently extract target compound's vapors in forensic and environmental applications. An improved recovery for VOCs was achieved with a cryofocusing system while extracting at -10 C, but it was found to be impractical for field sampling.
View Article and Find Full Text PDFA rapid method for the characterization of both organic and inorganic components of gunshot residues (GSR) is proposed as an alternative tool to facilitate the identification of a suspected shooter. In this study, two fast screening methods were developed and optimized for the detection of organic compounds and inorganic components indicative of GSR presence on the hands of shooters and non-shooters. The proposed methods consist of headspace extraction of volatile organic compounds using a capillary microextraction of volatiles (CMV) device previously reported as a high-efficiency sampler followed by detection by GC-MS.
View Article and Find Full Text PDFElemental analysis of glass was conducted by 16 forensic science laboratories, providing a direct comparison between three analytical methods [micro-x-ray fluorescence spectroscopy (μ-XRF), solution analysis using inductively coupled plasma mass spectrometry (ICP-MS), and laser ablation inductively coupled plasma mass spectrometry]. Interlaboratory studies using glass standard reference materials and other glass samples were designed to (a) evaluate the analytical performance between different laboratories using the same method, (b) evaluate the analytical performance of the different methods, (c) evaluate the capabilities of the methods to correctly associate glass that originated from the same source and to correctly discriminate glass samples that do not share the same source, and (d) standardize the methods of analysis and interpretation of results. Reference materials NIST 612, NIST 1831, FGS 1, and FGS 2 were employed to cross-validate these sensitive techniques and to optimize and standardize the analytical protocols.
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