Jonas Malmborg , Magnus Larsson , Lars Jaeger , Anders Nordgaard
{"title":"Transfer, persistence, contamination and background levels of inorganic gunshot residues","authors":"Jonas Malmborg , Magnus Larsson , Lars Jaeger , Anders Nordgaard","doi":"10.1016/j.forc.2024.100577","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100577","url":null,"abstract":"<div><p>This paper summarises the available literature data for the evidential evaluation topics of <em>transfer</em> (196 experiments), <em>persistence</em> (63 time series), <em>contamination</em> (1515 samples), and <em>background</em> prevalence (2158 samples) of inorganic gunshot residues (IGSR). In-house data on IGSR transfer, and the prevalence and persistence of IGSR on different types of glove are also contributed.</p><p>Combining new and previously published data in a meta-analysis, we report the following findings: The median transfer rate of IGSR was 11 % and the probability distribution of contact transfer was modelled using a Beta distribution. The half-life of IGSR on hands was estimated at 52 min. On gloves, decay followed a two-phase process with the slower process proceeding at a decreased rate compared to on hands (t<sub>1/2,slow</sub> = 77 min). The occurrence of characteristic IGSR on the hands of police officers was modelled using a generalised Pareto model (GPM). Combining the prevalence and the transfer probability models, a product probability distribution model was established. The product model estimates the probability of finding any amount of IGSR post-arrest on previously clean hands, estimating 8 % probability of non-zero transfer. Characteristic IGSR detected on the general public (1 % positives), on at-risk individuals (2 % positives), and in public places (0 % positives) showed low background levels. The likelihood of finding any amount of IGSR on the general public (at-risk included) was modelled using a GPM giving a 1.3 % probability of finding at least one, and 0.2 % probability to find more than three characteristic IGSR on the general public.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"39 ","pages":"Article 100577"},"PeriodicalIF":2.7,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140549516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the textile fibre’s analysis for forensics, utilizing FTIR spectroscopy and machine learning methods","authors":"Vishal Sharma, Mamta Mahara, Akanksha Sharma","doi":"10.1016/j.forc.2024.100576","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100576","url":null,"abstract":"<div><p>Fibres are prevalent and can be encountered as trace evidence in various situations. In cases of rape and physical assault, analyzing trace fibre components and assessing their transferability can establish connections between individuals and crime scenes or between perpetrators and victims. This study involved Attenuated Total Reflectance – Fourier Transform Infrared (ATR–FTIR) characterization of 104 fibre samples, including natural fibres like cotton and wool (43 samples) and terry wool and synthetic fibres (61 samples). Prominent peaks in different textile fibre spectra were primarily found in the fingerprint region (1800–450 cm<sup>−1</sup>). To simplify analysis, the spectral data was reduced to principal components, and sample discrimination was performed using Python’s PyCaret package. Multiple machine learning algorithms were explored for differentiating fibre samples, and the most effective one was selected for further validation. This study demonstrates the feasibility of developing an ATR-FTIR database for additional textile fibre samples, aiding in the detection of unknown or suspect fibres in the future.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"39 ","pages":"Article 100576"},"PeriodicalIF":2.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140536220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raghu Venkatapathy , Ryan Kauchak , Jacob Botkins , Matthew L. Magnuson
{"title":"Degradation of immediate precursors of fentanyl and fentalogs","authors":"Raghu Venkatapathy , Ryan Kauchak , Jacob Botkins , Matthew L. Magnuson","doi":"10.1016/j.forc.2024.100573","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100573","url":null,"abstract":"<div><p>Remediation of clandestine laboratory and processing operations for fentanyl and its analogs (i.e., fentalogs) may involve application of oxidants, most commonly household hypochlorite bleach, to chemically degrade the fentanyl to enable disposition of the site. While the chemical degradation of fentanyl has been reported, the degradation of immediate precursors has not been. Chemical degradation of fentanyl and fentalogs can cause these immediate precursors to reform. The immediate precursors of fentanyl investigated here are norfentanyl and 4-ANNP, which are controlled substances, along with norcarfentanil, precursor for carfentanil and remifentanil. The 4-ANNP was degraded within minutes in chlorine bleach, somewhat faster than fentanyl itself, whereas norfentanyl and norcarfentanil showed apparent degradation half lives up to days. Also, degradation rates were reduced in the presence of common diluents, like cutting agents, with apparent half-lives of several weeks for fully dissolved solutions. When the fentalog was added as a powder, globules were observed which could indefinitely prevent contact between the chlorine and the contents of the globules, prolonging persistence unless the globules are mechanically or otherwise broken. Because of shared structural characteristics among fentalogs, such as presence of reactive nitrogen groups, the results of this study may be applicable to a wide array of fentalogs. This study may also help inform remediation and waste management strategies to provide not only effective remediation of contamination, but also reduce the possibility that wastes of controlled substances are handled inappropriately, e.g., leading to continued personnel exposure and/or reprocessing of controlled substances.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"39 ","pages":"Article 100573"},"PeriodicalIF":2.7,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140330677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a novel seized drug screening method utilizing DART-MS and used weigh paper","authors":"Alleigh N. Couch, J. Tyler Davidson","doi":"10.1016/j.forc.2024.100572","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100572","url":null,"abstract":"<div><p>The conventional analytical scheme for seized drug analysis utilizes quick and cost-effective presumptive testing, such as color tests, followed by more discriminatory techniques, such as gas chromatography-mass spectrometry (GC–MS). Before the seized drug evidence is analyzed, the evidence is weighed using an appropriate weighing matrix and balance. Typically, the weighing matrix is discarded as chemical waste; however, the process of weighing the evidence leads to the deposition of drug residue onto the weighing matrix, which is then amenable to rapid analysis using ambient ionization approaches, such as direct analysis in real time mass spectrometry (DART-MS). This study demonstrates a DART-MS method for the rapid screening of seized drug evidence using filter paper and glassine paper weighing matrices commonly found in forensic laboratories. Validation experiments were performed using filter paper and glassine paper and compared to the results obtained using glass capillaries to assess the effectiveness of each weighing matrix. A total of 40 authentic samples, 20 filter papers and 20 glassine papers, were analyzed and the resulting spectra were searched using the National Institute of Standards and Technology (NIST) DART-MS Forensics Database and Data Interpretation Tool (DIT). When compared to the ground truth GC–MS results, the developed approach had a 90% correct identification rate, with all misidentifications being due to the presence of tablets rather than powder. The developed DART-MS screening method provides the seized drug community with a method to rapidly screen seized drug residue remaining from the weighing process and to improve the overall laboratory efficiency.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"39 ","pages":"Article 100572"},"PeriodicalIF":2.7,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140290653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of the Cross-Contamination of explosive canine training aids during manufacturing and storage","authors":"Kymeri Davis, John V. Goodpaster","doi":"10.1016/j.forc.2024.100571","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100571","url":null,"abstract":"<div><p>Explosive detecting canines should be trained using real explosive materials that have minimal contamination by other explosive odors to ensure accurate identification of potential threats. Therefore, the potential for cross-contamination between training aids is of importance. There are various storage methods in use by canine handlers, such as plastic and cloth bags, but these can lead to cross-contamination between training aids during storage. Alternatively, odor-permeable membrane devices (OPMD) may store training aides and be used as a delivery device. OPMDs allow for volatile compounds from the training aids to be released during training while helping to prevent contaminants from entering the device. However, the amount of contamination in a training aid upon receipt from a vendor is outside the control of canine handlers. To test the initial cross-contamination levels of training aids, 11 explosive materials were ordered from three different vendors. A 1-gram sample of each was collected and analyzed using gas chromatography – mass spectrometry. In several cases, explosive materials that are commercially available already exhibit elevated levels of contamination. This indicates that training aids must be acquiring contamination during manufacturing and/or storage at the vendor facility. The cross-contamination of explosive canine training aids stored in OPMDs was further evaluated and compared to traditional storage methods by storing various combinations of storage containers with explosives and using activated charcoal strips to collect the volatile compounds. Only one type of storage container, a Velcro bag, showed evidence of contamination.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100571"},"PeriodicalIF":2.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140186980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Initial results from SEM-EDX and LA-ICP-MS chemical characterisation of barium titanate glass microspheres","authors":"Thomas Scholz , Andreas Gärtner","doi":"10.1016/j.forc.2024.100569","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100569","url":null,"abstract":"<div><p>Barium titanate glass microspheres are used in a variety of applications, particularly for retroreflective materials, owing to their high refractive index. These microspheres can be released into the environment or found at crime scenes due to damage or decomposition. Chemical characterisation of barium titanate glass microspheres using SEM-EDX and LA-ICP-MS showed a good discrimination of the studied materials from each other. The ubiquitously used material has the potential to characterise microtraces at crime scenes or sources of anthropogenically induced particle release in environmental studies, making it a valuable feature.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100569"},"PeriodicalIF":2.7,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140191476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mirjam de Bruin-Hoegée , Ruthmara Corzo , Peter D. Zoon , Peter Vergeer , Jorien Schoorl , Marcel J. van der Schans , Daan Noort , Arian C. van Asten
{"title":"Evaluating the strength of evidence of elemental profiling of polymers with LA-ICP-MS","authors":"Mirjam de Bruin-Hoegée , Ruthmara Corzo , Peter D. Zoon , Peter Vergeer , Jorien Schoorl , Marcel J. van der Schans , Daan Noort , Arian C. van Asten","doi":"10.1016/j.forc.2024.100570","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100570","url":null,"abstract":"<div><p>LA-ICP-MS is a powerful technique for obtaining a forensic elemental profile of polymer evidence materials. However, the lack of homogeneous polymer reference standards hampers database creation and reliably matching a sample to a specific source. Therefore, the current study aims to evaluate the strength of evidence of forensic polymer comparisons by applying a matrix-matched reference standard with known concentrations for elements of interest. Four datasets of tapes, electrical wires, tubing, and jerrycans were compiled using LA-ICP-MS. It was found that quantification with the new PVC standard or by simply using the response of one element as internal standard significantly reduced the between-run variation. For each class of polymeric materials, characteristic elements could be identified with PCA and LDA. To facilitate classification, elemental concentrations were found to be typical for specific colors and types of polymeric materials. For forensic comparison, a score-based Bayesian likelihood ratio model and the <em>t</em>-test overlap method performed better than the feature-based model and 4-sigma criterion, in terms of rates of misleading evidence. Normalization to <sup>13</sup>C and quantification with the PVC standard with and without prior normalization to <sup>13</sup>C slightly reduced rates of misleading evidence. The <em>t</em>-test method showed an overall average false inclusion rate of only 0.45% and a false exclusion rate of 2.4%. Maximum calibrated likelihood ratios of 0.014 to 1778 were found for the tape dataset. In conclusion, this study demonstrates that with the use of proper standards, quantitative elemental profiling with LA-ICP-MS is a promising tool for forensic classification and comparison of polymers.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100570"},"PeriodicalIF":2.7,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2468170924000225/pdfft?md5=5c5bcb8bb33403d98b3a31e531529f8b&pid=1-s2.0-S2468170924000225-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140186929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A naked-eye colorimetric assay for highly sensitive detection of CL-20 explosive","authors":"Jian Tang , Jinxiang Wu , Yi He","doi":"10.1016/j.forc.2024.100568","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100568","url":null,"abstract":"<div><p>2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) stands as the most energetically condensed explosive ever found, and poses a great security threat to humans. Here we report a naked-eye colorimetric assay for highly sensitive detection of CL-20. Through effective cascading of the hydrolysis process of CL-20 with nitrite-involved Griess reaction to yield a pink-colored azo product, the visual quantification of CL-20 is realized by taking advantage of corresponding colorimetric signals. Under optimal experimental conditions, the present colorimetric assay is successfully used for highly selective determination of CL-20 in deionized water and environmental water samples with a nanomolar sensitivity. The resulting limit of detection is much lower than conventional methods. Moreover, benefiting from the distinct color change of the detection solution, direct naked-eye semi-quantitative analysis of CL-20 is achieved with a threshold concentration of 1 μM. Such simple, cost-effective, selective, and highly sensitive visual colorimetric assay will have valuable applications in public safety, environmental monitoring, and other related fields.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100568"},"PeriodicalIF":2.7,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140134399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Assessment of performance rates on the elemental comparison of small and irregular glass fragments using µ-XRF and LIBS","authors":"Oriana Ovide , Ruthmara Corzo , Tatiana Trejos","doi":"10.1016/j.forc.2024.100567","DOIUrl":"10.1016/j.forc.2024.100567","url":null,"abstract":"<div><p>This study describes a systematic assessment of the performance rates when analyzing small and irregular glass fragments using micro-X-ray Fluorescence Spectrometry (µ-XRF) and Laser Induced Breakdown Spectroscopy (LIBS). One hundred glass fragments were collected from the inner and outer panes of a vehicle windshield to assess the false exclusion rates. Additionally, 100 glass fragments originating from different vehicle windshields were used to evaluate the discrimination capabilities. To compare the effects of fragment size on the performance rates, half of the collected fragments were small (longest length between 0.4 mm and < 1 mm, and thickness greater than 0.4 mm for LIBS and 0.1 mm for μ-XRF), and the other half were full-thickness fragments (2 mm and greater). The study shows that precision deteriorates for small/irregular fragments and comparison items must have a similar size, shape, and thickness to minimize error rates. Thus, comparisons between full-thickness and small/irregular fragments should be avoided, regardless of the analytical method. Although this general concept is well known for µ-XRF, this effect was not previously reported as a concern for LIBS. Moreover, this study provides new sampling and comparison recommendations when using modern silicon drift detectors (SDD) and reduced fragment size. Using a 3 s (3 %RSD) comparison interval reduces the false exclusion rates to < 12 % for µ-XRF, and to < 4 % for LIBS when using either a 3 s or 4 s (3 % RSD) criterion. At least 4 known fragments are recommended for full thickness fragments and 6 to 9 known fragments for the small/irregular comparisons.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100567"},"PeriodicalIF":2.7,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of bioluminescence assay to assess PCR carryover contamination in forensic DNA laboratories","authors":"Tetsuya Satoh , Yukinobu Kutsuwada , Shota Inokuchi , Takenori Ishida , Takeshi Ikeda , Ryuichi Hirota , Akio Kuroda , Kazutoshi Matsumura , Susumu Iwase","doi":"10.1016/j.forc.2024.100566","DOIUrl":"https://doi.org/10.1016/j.forc.2024.100566","url":null,"abstract":"<div><p>In forensic DNA testing, PCR-based multilocus short tandem repeat (STR) profiling kits, which have high sensitivity and discriminatory power, are generally used to analyze autosomal and Y-chromosomal DNA profiles. Forensic DNA laboratories require strict quality control for DNA testing, as contamination during analyses leads to incorrect interpretation of DNA profiles. Here, we aimed to apply bioluminescence assay to detect and monitor residual PCR products on laboratory work area and equipment surfaces by targeting dATP in the PCR product and allelic ladder marker. Two commercially available bioluminescence assay kits (CheckLite HS Plus and UltraSnap™) were examined for their sensitivity after confirming their reactivity to dATP. In the assay using CheckLite HS Plus, the lower detectable sample volumes were calculated as 10 pl of PCR product of GlobalFiler and PowerPlex Fusion and 1 pl of PCR product of Yfiler Plus and the allelic ladder marker of GlobalFiler, whereas those in the assay using UltraSnap™ were calculated as 1 nl of PCR product and allelic ladder marker. The sample volumes of these kits were lower than those detected through electrophoresis. Thus, the sensitivity of these kits was sufficient to control PCR carryover contamination in the post-PCR areas. Furthermore, residual PCR products in the post-PCR areas were continuously monitored using a bioluminescence assay. The results showed that the bioluminescence values increased after handling PCR samples for electrophoresis and decreased after decontamination. Therefore, we concluded that the bioluminescence assay is useful for assessing PCR carryover contamination in post-PCR processes in forensic DNA laboratories.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"38 ","pages":"Article 100566"},"PeriodicalIF":2.7,"publicationDate":"2024-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140031356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}