Forensic Chemistry最新文献

{"title":"Optimization and validation of the fast blue BB (FBBB) screening test for the detection of delta-9-tetrahydrocannabinol (Δ9-THC) in oral fluid","authors":"Roberta Gorziza,&nbsp;Nicole Valdes,&nbsp;Marilyn Tinoco,&nbsp;Jose Almirall","doi":"10.1016/j.forc.2023.100514","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100514","url":null,"abstract":"<div><p>The fast blue BB test (FBBB) colorimetric test has been previously validated for the differentiation between marijuana-type and hemp-type cannabis plants. Individuals under the influence of delta-9-tetrahydrocannabinol (Δ9-THC) may be impaired to perform activities such as driving and the rapid, on-site detection of recent use of Δ9-THC could help to prevent traffic accidents. The current study describes, for the first time, the optimization and validation of the FBBB color test from oral fluid (OF) for field use. The FBBB reaction with Δ9-THC forms a red chromophore and a bright red fluorophore that is visualized with a portable fluorescence reader under UV light. The test was optimized for a miniaturized reaction on a 6.3 mm diameter glass fiber filter spot. The limit of detection (LOD) was established as 0.5 µg/mL or 500 ng/mL of Δ9-THC in OF (5 ng of Δ9-THC on the spot) by fluorescence detection. Other figures of merit include linearity in the 0.5–10 µg/mL range, acceptable precision (9.6–28% RSD) and an accuracy of ± 23.2–56.2%. Results from interference studies using different OF collection devices and substances are reported. Interferences might also occur when minor cannabinoids (CBD, CBN, CBG, and Δ8-THC) and Δ9-THC metabolites (THC-COOH and THC-OH) are also present in the matrix. Pre-loaded FBBB reagent is stable on the substrate when stored below 4 °C for 15 days and the color and fluorescence persist on the spot for at least 30 days post reaction. Future studies include development of an OF extraction procedure coupled to a prototype device for field application.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100514"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1824846","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":"Conjunctive use of mineralogy and elemental composition for empirical forensic provenancing of topsoil from Canberra, Australia","authors":"Michael G. Aberle ,&nbsp;Ulrike Troitzsch ,&nbsp;James Robertson ,&nbsp;Jurian A. Hoogewerff","doi":"10.1016/j.forc.2023.100524","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100524","url":null,"abstract":"<div><p>The capability to spatially triage geographical areas as low and high interest has the potential to provide valuable information as forensic intelligence to law enforcement operations, and related provenancing applications. Among others, our previously published work has largely been based on the elemental composition of topsoil samples, omitting other potentially useful compositional characteristics, such as mineralogy, that have proven valuable in forensic casework discriminations. In this contribution, a total of 334 topsoil (0–5 cm sampling depth; 0–75 µm fraction) samples collected from the Canberra region in Australia, were selected from a larger collection (n = 685) and their bulk mineralogy determined using X-ray powder diffraction (XRPD). Utilising an existing casework technique for discriminating soils by mineralogy, a total of twelve diagnostic peaks were selected representing commonly occurring minerals. Peak intensities were normalised relative to the sum of their intensities and used to create an indicative mineralogy dataset for the study region. Based on an existing algorithm for assigning investigative analytical similarities from overlapping areas between two Cauchy distributions, the provenance was estimated for thirteen blind topsoil samples. Provenance maps based on the mineralogy were subsequently combined with earlier elemental-based predictions, incorporating contrasting discriminatory capabilities from both techniques. Results indicate the mineralogical component of topsoils can provide accurate provenance predictions, and when combined with those based on the elemental composition, can further delineate areas as low interest that otherwise would not necessarily be differentiated from one technique alone.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"36 ","pages":"Article 100524"},"PeriodicalIF":2.7,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2620247","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":"Review: Headspace components of explosives for canine non-detonable training aid development","authors":"Alison Simon ,&nbsp;Ta-Hsuan Ong ,&nbsp;Alexandra Wrobel ,&nbsp;Ted Mendum ,&nbsp;Roderick Kunz","doi":"10.1016/j.forc.2023.100491","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100491","url":null,"abstract":"<div><p>Explosives detection canines are a versatile capability used to protect civilians and military personnel from concealed explosives, and their effective training requires exposure to the headspace odors of energetic materials. However, the hazardous nature of energetic materials presents challenges when training needs to be performed near other human activities. Non-hazardous, non-detonable training aids for explosives are useful for this purpose. To facilitate the design of these safer, alternative, training aids, this review summarizes the headspace components that have been measured from seventeen explosive targets: nitroaromatics (trinitrotoluene [TNT] and picric acid), nitrate esters (pentaerythritol tetranitrate [PETN], erythritol tetranitrate [ETN], dynamite, nitroglycerin, smokeless powder, and ethylene glycol dinitrate [EGDN]), salts (potassium chlorate, ammonium nitrate, and urea nitrate), black powder and sulfur powder, nitramines (1,3,5,-trinitro-1,3,5-triazine [RDX], including plastic explosives like Composition 4 [C-4]), and peroxides (triacetone triperoxide [TATP], hexamethylene triperoxide diamine [HMTD], diacetone diperoxide [DADP], and hydrogen peroxide). The compiled chemical vapors are separated based on how frequently they have been reported, and a list of the most widely observed compounds is provided. Additional <em>meta</em>-analyses found varying degrees of research interest across targets. For example, TATP and smokeless powder have more references than black powder and ETN. Most measurements are also qualitative, with solid phase microextraction gas chromatography mass spectrometry (SPME-GC/MS) being the most popular approach. From this review, summaries of headspace composition and characterization approaches are made available to facilitate the development and testing of canine training aids for explosives.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100491"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2574739","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":"Transfer and persistence studies of inorganic and organic gunshot residues using synthetic skin membranes","authors":"Courtney Vander Pyl ,&nbsp;Kourtney Dalzell ,&nbsp;Korina Menking-Hoggatt ,&nbsp;Thomas Ledergerber ,&nbsp;Luis Arroyo ,&nbsp;Tatiana Trejos","doi":"10.1016/j.forc.2023.100498","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100498","url":null,"abstract":"<div><p>The complex nature of gunshot residue (GSR) transfer and persistence introduces challenges and skepticism in its evidential value. Therefore, this work evaluates the behavior and movement of inorganic and organic gunshot residues to assist in the evidence interpretation. The study encompassed over 650 samples, including 247 collections from human skin after firing a gun and 405 synthetic skin and fabric substrates after depositing a characterized pGSR/OGSR standard. Transfer and persistence experiments were evaluated on different substrates (hands, ears, nostrils, forehead, hair, fabrics, and synthetic skin), at different times after firing (0 to 6 h), and common post-shooting activities (rubbing hands, handshaking, running, washing hands and fabrics). Ground truth knowledge of particle counts and analyte concentrations was used to calculate the recovery for inorganic and organic constituents from clothing and a synthetic skin membrane (StratM®). Authentic shooter skin samples were compared to synthetic skin to establish the validity of skin-substitute models. During controlled experiments, inorganic particles persisted longer than OGSR on inactive samples (9% and &lt; 25% loss at 6 hrs, respectively), but inorganic particles were more prone to secondary transfer than OGSR (up to 35% vs. 0% transfer, respectively). High percentages of particles were lost during vigorous activities like washing hands (99% loss) or rubbing hands (55% loss). In comparison, less loss was observed during the same studies for OGSR (&lt;21%). This study offers a deeper understanding of gunshot residue transfer and persistence mechanisms that can assist analysts and investigators in improving sample collection and interpretation of evidence.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100498"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3140269","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":"Potential of direct immersion solid-phase microextraction to characterize dissolved volatile organic compounds released by submerged decaying rat cadavers","authors":"Marta Malevic,&nbsp;François Verheggen,&nbsp;Clément Martin","doi":"10.1016/j.forc.2023.100488","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100488","url":null,"abstract":"<div><p>The decomposition process involves the degradation of carbohydrates, nucleic acids, proteins and fats, and leads to the release of volatile organic compounds (VOCs) among many other decomposition by-products. Despite the extensive literature on the VOCs emitted in the air from vertebrate corpses, there is a lack of research dedicated to aquatic decomposition. In this study, we aimed to evaluate the potential of direct immersion solid-phase microextraction gas chromatography coupled with mass spectrometry (DI-SPME/GC/MS) to characterize dissolved cadaveric VOCs. Dimethyl disulphide and indole -two compounds commonly released during decomposition- were selected to evaluate and set the optimal methodological parameters, which were found to be 10 min of collection performed under 27.5 °C and a stirring rate of 250 rpm. Using responsive surface methodology, the obtained curves highlighted the appropriate conditions for the dissolved cadaveric volatilome analysis. The method allows to trap 17 dissolved cadaveric VOCs, including commonly encountered compounds such as dimethyl disulfide, 9-hexanoic acid, dimethyl trisulfide and indole. DI-SPME/GC/MS has therefore potential for the identification of dissolved cadaveric VOCs, pending further tests are performed to optimize the method and make it capable of detecting all dissolved VOCs, through all stages of decomposition.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100488"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1824847","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":"A study on the occurrence of glass and paint across various cities in the United States–Part II: Background presence of paint in the general population","authors":"Lauryn C. Alexander ,&nbsp;Andra D. Lewis ,&nbsp;Olivia Duffett ,&nbsp;James Curran ,&nbsp;Patrick Buzzini ,&nbsp;Tatiana Trejos","doi":"10.1016/j.forc.2023.100493","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100493","url":null,"abstract":"<div><p>The frequency of occurrence of paint in the general population was estimated in four U.S. cities; Houston, TX, Huntsville, TX, Morgantown, WV, and Pittsburgh, PA. A total of 1,883 garment and footwear areas were sampled from the 410 participants. From these volunteers, up to six garment areas were sampled for the presence of paint and glass. Recovered paint particles were analyzed via microscopy<span> and micro-FTIR spectroscopy. Overall, 111 paint fragments were recovered from 21% of all the participants, with the Houston set yielding 50% of those fragments, while 21% came from the Morgantown set, 26% from the Huntsville set, and 3.6% from the Pittsburgh set. Paint particles were recovered primarily on the upper surfaces and lower surfaces of the garments. Much of the paint recovered was single-layered architectural or automotive paint with various binders and pigment compositions. The general trends and differences of paint fragments from these cities are discussed, including the effects on the frequency rates of the types of garments and footwear worn and the main modes of transportation. The concurrent presence of both glass and paint being recovered from the same individual was rare, and even more uncommon to find both traces in a single item. In this case, there was only one individual in the Houston set who had both types of particles on their person, and no garment areas or footwear areas with both traces present.</span></p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100493"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1636413","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":"Analyzing the color of forensic textile using smartphone-based machine vision","authors":"Can Hu,&nbsp;Hongcheng Mei,&nbsp;Hongling Guo,&nbsp;Ping Wang,&nbsp;Yajun Li,&nbsp;Haiyan Li,&nbsp;Jun Zhu","doi":"10.1016/j.forc.2023.100500","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100500","url":null,"abstract":"<div><p>Color is an important characteristic of textile, and its analysis is of great significance for the forensic characterization of textile. The colorimetry method based on visual observation provides a subjective assessment; the instrument-based color analysis method is objective but requires expensive equipment and professional technicians. In this study, a smartphone-based machine vision method for color analysis was established. A smartphone with a camera was used for image acquisition, and the free software ImageJ was used for image processing. The captured RGB image was first converted to a Lab Stack, and then the target area was selected for <em>L*a*b*</em> value analysis. The influence of acquisition equipment, light source, illumination/photography angle and distance, and sample on color analysis was investigated. Fifteen red textile pieces were analyzed using optimized machine vision methods, and the results were compared with those obtained using the microspectrophotometry by both hierarchical cluster analysis and K-means clustering method. The results of the two methods were consistent, thereby confirming the reliability of the machine vision method. The smartphone-based machine vision color analysis method is cheap, simple, accurate, and objective; thus, it has great potential to be widely used in forensic science.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100500"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3270917","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":"Forensic analysis of nail polish traces on different substrates using ATR-FTIR spectroscopy and chemometric methods","authors":"Lim Ka Khei ,&nbsp;Rajesh Verma ,&nbsp;Eva Lee Yin Tan ,&nbsp;Dzulkiflee Ismail ,&nbsp;Muhammad Naeim Mohamad Asri","doi":"10.1016/j.forc.2023.100503","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100503","url":null,"abstract":"<div><p>Nail polish can be important evidence in crimes like murder, rape, and suicides. Due to its prevalence, it can be important corroborative evidence in crime reconstruction. This paper reports the use of non-destructive ATR-FTIR spectroscopy combined with chemometrics for the discrimination of 79 nail polish samples of 8 brands. Differences in peak patterns, their absorbance, and the presence or absence of specific components in the chemical composition were examined in the ATR-FTIR technique prior to the discrimination with the statistical PLS-DA model. An excellent classification of samples was obtained according to the brands. The performance of PLS-DA through receiver operating characteristic (ROC) curves shows near-perfect results for the classification of the nail polish brands. Because nail polish can be found on many types of substrates such as paper, jeans, plastic, cloth, etc at the crime scene, we have tested all the unknown traces on such substrates and again, all the unknown samples (100%) in six substrates viz. cotton, jeans, white paper, polyester, tissue and nylon were correctly attributed to their source brand using the already trained PLS-DA model. The proof of concept demonstrated has potential applications in forensic casework.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100503"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3449529","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":"Machine learning methods for classifying novel fentanyl analogs from Raman spectra of pure compounds","authors":"Phillip Koshute ,&nbsp;N. Jordan Jameson ,&nbsp;Nathan Hagan ,&nbsp;David Lawrence ,&nbsp;Adam Lanzarotta","doi":"10.1016/j.forc.2023.100506","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100506","url":null,"abstract":"<div><p>In previous research, we demonstrated the promise of detecting novel fentanyl analogs from mass spectra using machine learning models. This approach complements existing library matching methods and provides a key capability amid the recent sharp increase in abuse of fentanyl and its analogs. However, many applications rely upon portable devices such as Raman spectrometers, rather than mass spectrometers that are generally located in laboratories. In response, we adapted our models to Raman-based sensing, devising a machine learning approach for detecting novel fentanyl analogs from Raman spectra. Whereas mass spectra consist of well-defined discrete peaks, Raman spectra are continuous. To aid model development, we extracted features from each spectrum using smoothing, background subtraction, and principal component analysis (PCA). Additionally, we extracted features related to spectral peaks and similarity to spectra of known compounds; these features were guided by subject-matter expertise. We also used a third feature set that combined the features from PCA and from spectral peaks. With these three feature sets as inputs, we developed fentanyl analog classification models using various machine learning techniques. These techniques included multi-layer perceptron, neural network, partial least squares, penalized multinomial regression, random forest, regularized logistic regression, support vector machines, and extreme gradient boosting. We developed and tested our models using 320 Raman spectra of pure compounds, assessing performance via cross-validation. Models with PCA-based features performed better than those using expert-based features, achieving more than 90% probability of detection alongside less than 1% probability of false alarm. Although fentanyl compounds are often found with other components (e.g., cutting agents), some applications such as mail screening may encounter relatively pure fentanyl analogs. The results within this study suggest that our machine learning models are particularly promising for such applications.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100506"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2575486","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":"Determination of fentanyl and acetylfentanyl in soil in their intact form and orthogonal corroboration of their presence by EI-GC-MS using chloroformate chemistry","authors":"Carlos A. Valdez ,&nbsp;José A. Rosales ,&nbsp;Roald N. Leif","doi":"10.1016/j.forc.2023.100504","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100504","url":null,"abstract":"<div><p>In the field of forensic chemistry, methods for identifying and characterizing illicit drugs remain of great interest to government and law enforcement entities. To this end, the unambiguous identification of a drug in the environment (e.g., soil) prompts further investigation into the possibility of a clandestine point of production for such drug. In this report, a method for the analysis of the two common synthetic opioids fentanyl and acetylfentanyl in a soil matrix when present separately at 1 and 10 μg/g by electron ionization gas chromatography-mass spectrometry (EI-GC-MS) is presented. The method involves the initial extraction of the intact opioids followed by their reaction with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl) to predictably generate Troc-modified norfentanyl, Troc-noracetylfentanyl and 2-phenylethyl chloride products that can be used to retrospectively corroborate the identity of the opioid by EI-GC-MS. Estimated method detection limits (MDLs) for the Troc-norfentanyl and Troc-noracetylfentanyl species were 15.4 and 13.6 ng/mL respectively from the soil matrix extracts employed (Virginia type A soil) while the calculated method’s LOQ values were 45.7 and 40.4 ng/mL respectively. The protocol presented herein describes for the first time the analysis of these highly toxic and common synthetic opioids in a soil matrix as well as their retrospective confirmation by analyzing the products arising from their reaction with Troc-Cl by EI-GC-MS.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"34 ","pages":"Article 100504"},"PeriodicalIF":2.7,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3140271","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}