Forensic Chemistry最新文献_第9页

High-Performance Thin-Layer Chromatography hyphenated with image processing and chemometrics as a tool for forensic discrimination of Cannabis sativa L. chemotypes 结合图像处理和化学计量学的高效薄层色谱法在大麻化学型鉴定中的应用

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-07 DOI: 10.1016/j.forc.2023.100528

Nataša Radosavljević-Stevanović , Aleksandra Kovačević , Dragan Manojlović , Petar Ristivojević

{"title":"High-Performance Thin-Layer Chromatography hyphenated with image processing and chemometrics as a tool for forensic discrimination of Cannabis sativa L. chemotypes","authors":"Nataša Radosavljević-Stevanović , Aleksandra Kovačević , Dragan Manojlović , Petar Ristivojević","doi":"10.1016/j.forc.2023.100528","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100528","url":null,"abstract":"<div><p><em>Cannabis sativa</em> L. is the most widely cultivated, trafficked, and abused illicit drug. The reliable distinction between drug type and fiber type <em>C. sativa</em> remains a topic of interest for forensic chemists. For the first time, we applied a combination of simple, cost-effective, and reliable High-Performance Thin-Layer Chromatography (HPTLC) with image analysis as well as sophisticated multivariate tools for differentiating <em>C. sativa</em> drug, fiber and intermediate chemotypes. After extraction, major cannabinoids from 43 seized <em>C. sativa</em> were separated using the HPTLC method. Peak areas of Δ<sup>9</sup>-THC, CBN, and CBD were calculated by simple image processing, and <em>Xfactor</em> = [THC + CBN]/CBD was determined as criteria used to discriminate three <em>C. sativa</em> chemotypes. The obtained results were compared with Gas Chromatography with Flame Ionization Detection (GC-FID) as the reference method for the determination of <em>Xfactor</em>.</p><p>Principal Component Analysis and Hierarchic Cluster Analysis were applied to classify three <em>C. sativa</em> chemotypes according to their chemical pattern. The proposed approach clearly distinguishes 26 drugs, 13 fiber, and 4 intermediate chemotypes in seized <em>C. sativa</em>, aligning with GC-FID analysis. The results showed that the HPTLC technique in combination with multivariate methods is an accurate and reliable tool for high-throughput and forensic screening of three <em>C. sativa</em> chemotypes. Compounds such as Δ<sup>9</sup>-THC and CBD were marked as the most important cannabinoids responsible for the classification of the seized <em>C. sativa</em> chemotypes.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"36 ","pages":"Article 100528"},"PeriodicalIF":2.7,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92041556","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}

引用次数: 0

A comparative analysis of different hair matrixes and matrix reference materials for quantitative hair analysis in drug tests 毛发药物定量分析中不同毛发基质及基质参比物的比较分析

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-07 DOI: 10.1016/j.forc.2023.100532

Min Lv , Liying Zhou , Zheng Qiao , Qing Xu , Xin Wang , Bin Di , Wei Liu , Hang Chen

{"title":"A comparative analysis of different hair matrixes and matrix reference materials for quantitative hair analysis in drug tests","authors":"Min Lv , Liying Zhou , Zheng Qiao , Qing Xu , Xin Wang , Bin Di , Wei Liu , Hang Chen","doi":"10.1016/j.forc.2023.100532","DOIUrl":"10.1016/j.forc.2023.100532","url":null,"abstract":"<div><p>The proposal of the concept of Precision Science and the rapid development of technology have raised expectations for a higher demand for accurate quantitative analysis, including hair analysis in drug tests. Many details are presently constraining improvements in precision, so there is a greater need for standardized methods to control and improve the analytical process in the laboratory. Hair matrix reference materials may become a feasible option. In the present study, 34 drug-free hair samples from healthy volunteers were collected and compared with 2 certified standard hair samples. It was observed that the hair matrix of different origins did have a significant impact on hair analysis. Three reference materials were prepared using spiking and two soaking methods, and one natural reference material was collected from real cases. A total of 57 authentic hair samples were measured from March to August 2022 using these 4 reference materials. Differences in the origins of samples were found to have a significant impact on the hair analysis results. The reference material soaked in water and methanol at a 1:1 ratio (v/v) appeared to be an excellent tool for daily quality control, as it gave results closest to those of the natural matrix reference material in all aspects and supported the law principle of the Presumption of Innocence.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"36 ","pages":"Article 100532"},"PeriodicalIF":2.7,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48049945","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}

引用次数: 0

Voronoi Natural Neighbours Tessellation: An interpolation and grid agnostic approach to forensic soil provenancing Voronoi自然邻居镶嵌:一种插值和网格不可知法证土壤溯源方法

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100522

Michael G. Aberle , James Robertson , Jurian A. Hoogewerff

{"title":"Voronoi Natural Neighbours Tessellation: An interpolation and grid agnostic approach to forensic soil provenancing","authors":"Michael G. Aberle , James Robertson , Jurian A. Hoogewerff","doi":"10.1016/j.forc.2023.100522","DOIUrl":"10.1016/j.forc.2023.100522","url":null,"abstract":"<div><p>Recently there has been an increase of work dedicated to developing a more objective soil provenancing capability. Notwithstanding the significant progress made, the presented provenancing techniques have predominately been based upon interpolation grids, generated from often arbitrary decisions of the user (e.g., grid cell size, grid placement, interpolation model, etc.). To address the acknowledged reproducibility issues, this paper introduces a spatial modelling technique based upon Voronoi Tessellations that is free from arbitrary user decisions. Termed herein as Voronoi Natural Neighbours Tessellation (VNNT), the proposed approach segments the survey area into many “honeycomb-like” polygons. Of which, the exact number, shape, location, and orientation of polygons are inherently dependent upon the original density of input sampling points from the survey, not a user’s subjective decision.</p><p>Utilising compositional geochemistry data from a fit-for-purpose topsoil survey and eleven “blind” soil samples from Canberra, Australia, we compare this proposed VNNT approach against a simpler Voronoi Tessellation, and a previously presented 500 m × 500 m grid following a modified and upscaled Natural Neighbour interpolation. Aside from also being computationally less intensive, our results indicated the proposed VNNT approach regularly yielded at least equal, or often more accurate provenance predictions than that of the gridded Natural Neighbour interpolation. Importantly, the delineation of individual polygons is fundamentally dependent upon the survey’s real sampling design, and most truthfully reflects the underlying sampling density, and associated uncertainties. Consequently, the VNNT approach is significantly less susceptible to expert bias as a result of subjective decision-making and “fine-tuning” of interpolation parameters.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100522"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43257073","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}

引用次数: 1

Study on electron ionization-mass spectrometry characteristic fragments and cleavage patterns of fentanyl-type new psychoactive substances 芬太尼类新型精神活性物质的电子电离-质谱特征片段和解理模式研究

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100518

Xuan Luo , Jing Peng , Kejian Huang , Xiaofeng Liu , Ning Yang , Qiulian Luo

{"title":"Study on electron ionization-mass spectrometry characteristic fragments and cleavage patterns of fentanyl-type new psychoactive substances","authors":"Xuan Luo , Jing Peng , Kejian Huang , Xiaofeng Liu , Ning Yang , Qiulian Luo","doi":"10.1016/j.forc.2023.100518","DOIUrl":"10.1016/j.forc.2023.100518","url":null,"abstract":"<div><p>Fentanyl-type new psychoactive substances (fentanyl-type NPS) are the primary subclass of synthetic opioid groups in new psychoactive substances (NPS). According to <em>World Drug Report 2022</em> by the United Nations Office on Drugs and Crime, fentanyl-type NPS are the major cause of overdose deaths in North America, where their abuse is the most severe. Given the multiple modification sites in the structures of fentanyl-type NPS, the derivatization rate is very rapid, causing more difficulties for analysis and identification in forensic laboratories. Because the fragments in electron ionization-mass spectrometry (EI-MS) spectra contain rich structural information and similar compounds have similar MS cleavage patterns and produce similar characteristic fragments, it is crucial to infer the structure of emerging fentanyl-type NPS by summarizing the cleavage patterns and distinct fragments of fentanyl-type NPS EI-MS data. In this study, 49 fentanyl-type NPS were analyzed using gas chromatography-MS (GC–MS) with EI and chemical ionization sources. Subsequently, the EI-MS cleavage rules and characteristic fragments of fentanyl-type NPS were summarized with the assistance of 129 fentanyl-type NPS GC–MS data obtained from <span>www.caymanchem.com</span><svg><path></path></svg>. Furthermore, a set of structural analysis procedures was established to determine the structures of emerging fentanyl-type NPS. This procedure laid the foundation for rapid identification and screening of fentanyl-type NPS.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100518"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46306535","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}

引用次数: 1

Error rate and similarity determination of latent fingerprint chemistry via 1D GC and GC × GC–MS 用1D GC和GC×GC-MS测定潜在指纹化学的错误率和相似度

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100521

Jessica Kindell , Candice Bridge

{"title":"Error rate and similarity determination of latent fingerprint chemistry via 1D GC and GC × GC–MS","authors":"Jessica Kindell , Candice Bridge","doi":"10.1016/j.forc.2023.100521","DOIUrl":"10.1016/j.forc.2023.100521","url":null,"abstract":"<div><p>In response to the National Academy of Science’s report on Strengthening Forensic Science, many researchers have investigated ways of improving and supplementing pattern-based visual methods for latent fingerprint (LF) analysis. Gas chromatography (GC) has been used to study the initial and aged chemistry of latent fingerprints, along with attempting to statistically asses same source association with donor characteristics. Since LFs are composed of a complex mixture of oil, sweat, and other components, sections within the chromatographic profile that have poor resolution could benefit from better separation of components, thus yielding more associations to the correct source. This study investigates the potential of increased source association using comprehensive two-dimensional (GC × GC) and one-dimensional (1D) gas chromatography-mass spectrometry (GC–MS). Three LFs from a sample of thirteen volunteers were collected, derivatized with boron trifluoride–methanol (BF<sub>3</sub>-MeOH), and analyzed via 1D GC and GC × GC–MS. The statistical strength of source association was performed by evaluating the log likelihood ratios (LLRs) obtained from the intra- and inter-personal pairwise Pearson correlation comparisons (PCCs) and using the normal and kernel density <em>comparison</em> R functions. The 1D GC method provided stronger same-source association due to high intra-personal PCC values; however, lower inter-personal PCCs were acquired from GC × GC. Higher area under the curves (AUCs) and LLR calibration were computed for the 1D GC PCCs. Conversely, poor statistical calibration and discriminating power were obtained for both 1D GC and GC × GC methods when assessing the LLRs despite having high AUCs.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100521"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43147397","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}

引用次数: 0

Synthesis, characterisation and quantification of the new psychoactive substance 1-(1,3-benzodioxol-5-yl)-2-(propylamino)butan-1-one (bk-PBDB, putylone) 新型精神活性物质1-（1,3-苯并二氧唑-5-基）-2-（丙氨基）丁-1-酮（bk-PBDB，putylone）的合成、表征和定量

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100523

David I. Dixon , Molly F. Millea , Alexander T. M. Wilcock , Andrew Costello , Jamie R. Ellison , Sacha Lord , Kim A. O'Brian , Ryan E. Mewis , Oliver B. Sutcliffe

{"title":"Synthesis, characterisation and quantification of the new psychoactive substance 1-(1,3-benzodioxol-5-yl)-2-(propylamino)butan-1-one (bk-PBDB, putylone)","authors":"David I. Dixon , Molly F. Millea , Alexander T. M. Wilcock , Andrew Costello , Jamie R. Ellison , Sacha Lord , Kim A. O'Brian , Ryan E. Mewis , Oliver B. Sutcliffe","doi":"10.1016/j.forc.2023.100523","DOIUrl":"10.1016/j.forc.2023.100523","url":null,"abstract":"<div><p>Synthetic cathinones are a continually evolving family of illicit drugs, with novel analogues frequently being detected. This paper reports the detection of 1-(1,3-benzodioxol-5-yl)-2-(propylamino)butan-1-one, bk-PBDB (putylone), within solid dosage forms (tablets) seized by law enforcement for the first time in the United Kingdom. The identity of the compound was confirmed <em>via</em> the synthesis of a pure bk-PBDB reference standard and direct spectral comparison by <sup>1</sup>H NMR and GC-EI-MS analysis. A full analytical profiling of bk-PBDB by nuclear magnetic resonance (NMR), attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy and gas chromatography-electron ionisation-mass spectrometry (GC-EI-MS) is reported and shows good concordance between the seized sample and the reference standard. A validated GC-EI-MS method for the routine quantification of the cathinone in bulk forensic samples (LOD: 0.09 μg/mL, LOQ: 0.26 μg/mL) was also developed and using this method, the seized tablets were determined to contain a mixture of bk-PBDB (130.6–135.5 mg/tablet) and caffeine (40.2–43.4 mg/tablet) respectively.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100523"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2468170923000590/pdfft?md5=3ec788feb5ef82402268a4d5828e78f8&pid=1-s2.0-S2468170923000590-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49189626","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}

引用次数: 0

Interpretation and report writing in forensic comparisons of paint evidence: An interlaboratory exercise 油漆证据的法医比较的解释和报告写作:一个实验室间的练习

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100513

Andria Mehltretter , Meghan Prusinowski , Hal Arkes , David Flohr , Cedric Neumann , Scott Ryland , Donna Sirk , Tatiana Trejos

{"title":"Interpretation and report writing in forensic comparisons of paint evidence: An interlaboratory exercise","authors":"Andria Mehltretter , Meghan Prusinowski , Hal Arkes , David Flohr , Cedric Neumann , Scott Ryland , Donna Sirk , Tatiana Trejos","doi":"10.1016/j.forc.2023.100513","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100513","url":null,"abstract":"<div><p>This interlaboratory study evaluated a guide for interpreting and reporting trace evidence examinations. The online survey aimed to assess the examiners' interpretation of casework scenarios designed by a subject matter expert panel (SMEP), specifically for paint evidence. A pool of 30 scenarios was created, and 15 were assigned to each participant using multi-factor design to evaluate agreement among examiners on case sets with different conclusion ranges and difficulty levels. Exploratory data analysis and three generalized mixed-effects models were used to assess the data. From the 1267 responses received from 85 participants, approximately 93% of responses were consistent between participants and within the SMEP consensus and the next best category, while 73% agreed with the SMEP consensus that was considered the ground truth. Most disagreements were observed in worst-case scenarios created with intended higher difficulty and complex circumstances.</p><p>The statistical models showed a strong positive relationship between the reported and expected conclusions, indicating that participants' findings align with the SMEP consensus. On the other hand, the exercise's difficulty level and participant's experience did not have a significant impact on the reported conclusions. However, the credible intervals for the probabilities of the different reported conclusions indicate that more experienced participants achieve greater consensus for a given exercise. The consensus reached among practitioners represents an advance in the trace community’s efforts to standardize reporting of results and opinions when following systematic criteria.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100513"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1754092","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}

引用次数: 0

Using ATR-FTIR spectroscopy and DD-SIMCA for ecstasy profiling 利用ATR-FTIR光谱和DD-SIMCA进行摇头丸分析

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100520

Danielle Kochenborger John , Rafael Dutra Soares , Patrícia dos Santos Corrêa , Klester dos Santos Souza , Marco Flôres Ferrão

{"title":"Using ATR-FTIR spectroscopy and DD-SIMCA for ecstasy profiling","authors":"Danielle Kochenborger John , Rafael Dutra Soares , Patrícia dos Santos Corrêa , Klester dos Santos Souza , Marco Flôres Ferrão","doi":"10.1016/j.forc.2023.100520","DOIUrl":"10.1016/j.forc.2023.100520","url":null,"abstract":"<div><p>Ecstasy is a recreational drug known to have serious adverse effects, necessitating the development of new techniques for its rapid and affordable identification in harm reduction policies and forensic laboratories. In this study, ATR-FTIR spectroscopy and DD-SIMCA (Data Driven Soft Independent Modeling of Class Analogy) were employed to determine the profile of ecstasy tablets and their adulterants. ATR-FTIR spectroscopy, which is a fast and non-destructive method that provides structural information, and DD-SIMCA, a supervised technique that distinguishes between different groups, were used. The Hierarchical Cluster Analysis (HCA) revealed the formation of two primary clusters: one comprising mainly MDA samples with some MDMA samples, and the second including cocaine, methamphetamine, and caffeine samples, as well as a mixture of MDA samples with methamphetamine and caffeine. Principal Component Analysis (PCA) was performed, and the first five principal components (PC) explained 86.25% of the total data variance. In the PC1xPC2 scores plot, the distribution of samples containing MDs (MDA and MDMA) was observed. Further analysis using PCA revealed the grouping of cocaine samples into two separate groups based on variations in concentration. The DD-SIMCA model demonstrated high sensitivity values in accurately identifying target samples (MDA) and relatively high specificity values in both the training and test sets. The study highlights the effectiveness of ATR-FTIR spectroscopy, PCA, and DD-SIMCA for the precise classification of ecstasy and its adulterants and suggests their potential in drug identification and analysis.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100520"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43021200","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}

引用次数: 1

All equal in the face of death! – Characterization of the volatile cadaveric compounds of fresh stage human corpses 在死亡面前人人平等!-新鲜阶段人类尸体挥发性尸体化合物的特性

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100516

Clément Martin, François Verheggen

{"title":"All equal in the face of death! – Characterization of the volatile cadaveric compounds of fresh stage human corpses","authors":"Clément Martin, François Verheggen","doi":"10.1016/j.forc.2023.100516","DOIUrl":"10.1016/j.forc.2023.100516","url":null,"abstract":"<div><p>The smell associated with the decomposition of a human body has been the subject of a limited number of studies, most using body parts or other vertebrates as surrogate models. Among the limitations frequently encountered in the existing literature are the small sample size and the high variability in terms of stages of decomposition. In the present study, we collected, identified, and quantified the volatile organic compounds released by 20 human corpses at the fresh stage, using dynamic headspace collection. We also assessed the impact of some parameters on the volatilome: skin temperature, gender, age, size, postmortem interval, presence of lividities or rigidities. We found 2-heptanone to account for nearly half the scent of fresh human cadavers. Four additional compounds were also repeatedly identified: dimethyl disulfide, ethyl acetate, limonene and 3-methyl-1-butanol. The use of dynamic sampling and thermodesorption traps has allowed to increase the diversity of collected postmortem molecules, compared to previous works. However, no human specific markers were found, either because they do not exist at the fresh stage, or because they are released at trace levels. Finally, none of the tested parameters impacted the volatile profile of human corpses. We recommend performing similar assays on more advanced stages to help completing our understanding of human decomposition.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100516"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46224124","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}

引用次数: 1

Monitoring the solid-state VIS profiles of degrading bloodstains 监测降解血迹的固态VIS特征

IF 2.7 3区医学

Forensic Chemistry Pub Date : 2023-09-01 DOI: 10.1016/j.forc.2023.100507

Kgalalelo Rampete , Colin I. Elliott , Theresa Stotesbury

{"title":"Monitoring the solid-state VIS profiles of degrading bloodstains","authors":"Kgalalelo Rampete , Colin I. Elliott , Theresa Stotesbury","doi":"10.1016/j.forc.2023.100507","DOIUrl":"https://doi.org/10.1016/j.forc.2023.100507","url":null,"abstract":"<div><p>Determining the time since deposition (TSD) of bloodstained evidence can be an important process in forensic investigations. Hemoglobin is often examined as a biomolecule of interest for these purposes due to the known <em>ex vivo</em> oxidative changes to its structure. These time-dependent oxidative processes have previously been probed using UV–VIS spectroscopy following the resuspension of bloodstains. Our study investigated the solid-state VIS spectra of degrading bloodstains without sample pre-treatment, effectively bypassing the need for resuspension. A total of 128 bloodstains from eight biological replicates were created and stored on glass slides in four temperature conditions: −20 °C, 4 °C, 22 °C, and 45 °C (see graphical abstract, created with <span>BioRender.com</span><svg><path></path></svg>). Spectra were acquired from 380−800 nm at five time points spanning 96 h. The peak area of the methemoglobin (metHb) band displayed the largest time and temperature differences, an interesting contrast to previous literature using the Soret band for TSD. Principal Component Analysis (PCA) demonstrated that storage temperature delineated the data, with the metHb band showing the greatest contributions to PC1. Linear mixed models from the PCA data with time showed clear TSD relationships with temperature, and with minimal inter-donor variability. Overall, this work complements the UV–VIS analysis of bloodstains for TSD estimation, with the importance of noting clear differences between phases and sample preparation methods.</p></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"35 ","pages":"Article 100507"},"PeriodicalIF":2.7,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3448717","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}

引用次数: 0