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ABSTRACT Forensic chemists frequently employ statistical profiling approaches to assess the degree of similarity between samples of illicit drugs. Such profiling information can help reveal connections between nodes in distribution networks and manufacturing laboratories. For amphetamine, the routine method of comparing a pair of samples includes the use of a dissimilarity measure based on the Pearson correlation coefficient calculated between their chemical profiles obtained through gas chromatography–mass spectrometry. This simple measure of (dis)similarity has been shown distinguish pairs sharing a common origin (e.g., same production batch) to a reasonable level of accuracy. However, Pearson correlation fails to capture all the relevant notions of similarity between chemical profiles of amphetamine. We present a new statistical method for forensic drug comparison that uses a more sophisticated statistical modelling approach to determine similarity between samples. We show that this leads to improved performance over the correlation‐based approach. The proposed method is easily extendable and has an intuitive interpretation both from chemistry and forensic perspectives, which supports wide applicability to illicit drug profiling in practice. [ABSTRACT FROM AUTHOR]

Chemical analysis aimed at identifying post‐explosion residues is critical for investigating crimes or accidents involving explosives, establishing it as a vital area of forensic chemistry. In general, only trace amounts remain in samples analyzed for this purpose, making the presence of interferents a constant concern. Therefore, understanding the materials used from collection to sample preparation is essential for this type of analysis. This study focuses on organic contaminants in collection and laboratory materials analyzed by gas chromatography/mass spectrometry (GC/MS), complementing a previous study by Mauricio et al. (2020), which addressed inorganic contaminants in materials used for similar purposes in ion chromatography (IC). No prior studies have specifically investigated the potential organic interferences introduced by various materials commonly used in forensic laboratories for sample pre‐processing, storage, and evidence collection in this context. Plastic films, bottle caps, disposable gloves, syringes, swabs, disposable cups, plastic tubes, and plastic pipettes were examined. GC/MS analyses revealed that certain materials, particularly syringe plungers, gloves, and plastic films, can interfere with the detection of post‐explosion residues from explosive emulsions and ANFO (ammonium nitrate‐fuel oil). These findings emphasize the importance of evaluating materials for potential interferences prior to sample collection and processing to minimize contamination risks. This study provides significant insights into how commonly used laboratory materials can impact forensic analysis, thereby enhancing the reliability of post‐explosion residue analysis and supporting more accurate forensic investigations. [ABSTRACT FROM AUTHOR]

Background Method Results Conclusion Approximately 1% of Sweden's 90 000 annual deaths were reported caused by poisoning. In this study, we aim to describe this poisoning population's characteristics, autopsy frequency and results of toxicology testing.A national cohort study based on Swedish national registers. All deceased subjects older than 18 years with poisoning as the cause of death registered between 1 January 2000 and 31 December 2021 were included. Causes of death according to primary ICD‐10 code were analysed along with the substances found in forensic chemistry testing.There were 27 057 poisonous deaths during the study periods 2 018 495 adult deaths. Subjects deceased due to poisoning had a median age of 53 years, and 18 838 (70%) were men. A private home was the most reported location of death (52%). In total, 23 260 (87%) did undergo some sort post‐mortem examination. Drugs (synthetic narcotics, opioids, heroin) caused 12 448 (46%) deaths, and alcohols explained 9056 cases (33%). Positive toxicological tests were found in 22 550 (83%) of the subjects. The most common separate substances were ethanol, zopiclone and nordazepam.Poisoning caused 1.3% of Swedish deaths. Men in their 50s were the most common victims, and their deaths were often cause by synthetic narcotics, other opioids or alcohol. The autopsy frequency was lower than expected for poisonous deaths. [ABSTRACT FROM AUTHOR]

The PowerPlex® 35GY System (Promega, USA) is an advanced eight-dye multiplex STR kit, incorporating twenty-three autosomal STR loci, eleven Y chromosome STR loci, one sex determining marker Amelogenin, and two quality indicators. This multiplex system includes 20 CODIS loci and up to 15 mini-STR loci with sizing values less than 250 bases. In this study, validation for PowerPlex® 35GY System was conducted following the guidelines of SWGDAM, encompassing sensitivity, precision, accuracy, concordance, species specificity, stutter, mixture, stability, and degraded DNA. The results from experiments demonstrated that the PowerPlex® 35GY System could effectively amplify DNA samples, with complete allele detection achieved at 125 pg. Moreover, over 90% of alleles from minor contributors were detected at a mixed ratio of 1:4. Additionally, the system was found to yield full profiles even in the presence of hematin, humic acid, and indigo. The PowerPlex® 35GY System demonstrated superior performance in the sensitivity and degraded DNA studies compared to a six-dye STR kit. Hence, it is evident that the PowerPlex® 35GY System is well-suited for forensic practice, whether in casework or for database samples. These findings provide strong support for the efficacy and reliability of the PowerPlex® 35GY System in forensic applications. [ABSTRACT FROM AUTHOR]

Forensic chemistry literature has grown exponentially, with many analytical techniques being used to provide valuable information to help solve criminal cases. Among them, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), particularly MALDI MS imaging (MALDI MSI), has shown much potential in forensic applications. Due to its high specificity, MALDI MSI can analyze a wide variety of compounds in complex samples without extensive sample preparation, providing chemical profiles and spatial distributions of given analyte(s). This review introduces MALDI MS(I) to forensic scientists with a focus on its basic principles and the applications of MALDI MS(I) to the analysis of fingerprints, drugs of abuse, and their metabolites in hair, medicine samples, animal tissues, and inks in documents. [ABSTRACT FROM AUTHOR]

Synthetic cocaine analogs are designer drugs that recently emerged as non‐controlled substitutes for their parent drug. Among them, nitracaine is of particular concern for its psychoactive effect. In this work, we present a thorough characterization of the electrochemical behavior of nitracaine, with a final quantification performed by differential pulse voltammetry (DPV) in ethanol/lithium perchlorate 0.1 M. The selectivity of the method and reproducibility of results were assessed. LOQ of 0.3 μg mL−1 and a linear dynamic range of up to 400 μg mL−1 were obtained. In addition, recoveries from 85 % to 101 % were achieved on both simulated and real samples. For nitracaine analysis in urine, a clean‐up and a preconcentration step by solid phase extraction (SPE) using the adsorbent Florisil have been developed and optimized through the Design of Experiments (DoE) strategy, thus achieving an enrichment factor of 20. [ABSTRACT FROM AUTHOR]

Butter is among the most popular and commercially valuable dairy products. Its high commercial value makes it a major target for adulteration, which aims to reduce production costs by using lower-quality fats and oils from other sources. The annual global market is around USD 30 billion (2023), expected to reach USD 36 billion in 2028, which also justifies the enormous interest in adulteration. In this work, a confirmed case of butter adulteration was studied by Nuclear Magnetic Resonance (NMR) and Stable Carbon Isotopic Ratio Analysis (SCIRA) techniques, employed to detect the inclusion in butter production of vegetable oils, such as soybean and palm oils. A total of 21 samples seized by the Brazilian Federal Police were analysed by NMR and SCIR, and compared to original butter obtained from commercial sources. The composition of all the seized samples was a mixture of butter (dairy fat of animal origin) with fat of vegetable origin (soybean and palm oil) and did not contain milk as a major component. While NMR was an unequivocal choice to discriminate the chemical composition of food samples, identifying the short-chain saturated fatty acids present in milk fat, including the butyryl alkyl chain, SCIRA was able to discriminate the origin of fat present in the butter samples as C3 sources, such as palm vegetable oils. [ABSTRACT FROM AUTHOR]

A quantitative gas chromatography mass spectrometry (GC/MS) method was developed for delta‐9‐tetrahydrocannabinol (delta‐9‐THC), delta‐8‐tetrahydrocannabinol (delta‐8‐THC), tetrahydrocannabinolic acid (THCA), and cannabidiol (CBD) in matrices including plant material, liquids and oils, waxes, edibles, and bath and body products. Samples were prepared by homogenization, extraction of the cannabinoids into solvent, liquid/liquid extraction, and derivatization. The GC/MS method was validated from 0.15% to 5.00% (weight basis) to encompass the 0.3% legal distinction between hemp and marijuana. Validation was performed assessing imprecision/bias, calibration model, recovery, interferences, limit of detection, matrix matching, carryover, accuracy, and an assessment of CBD conversion to delta‐9‐THC. The calibration curves were quadratic weighted 1/x with r2 > 0.990. The method had a detection limit of 0.075% in plant material for each analyte. Analyte recovery was greater than 70% in plant material. Carryover was not observed up to concentrations equivalent to 100% analyte, and no forensically significant conversion of CBD to delta‐9‐THC was observed. One cannabinoid isomer, 9(R)‐delta‐7‐tetrahydrocannabinol (9(R)‐delta‐7‐THC), was determined to interfere with the quantitation of delta‐9‐THC, but could be differentiated based on mass spectrum. The method was determined to be suitable for quantitation of delta‐9‐THC, delta‐8‐THC, delta‐9‐THCA, and CBD and was able to differentiate hemp samples from marijuana samples. [ABSTRACT FROM AUTHOR]

Within the complex world of disaster victim identification, or DVI, forensic science practitioners use a variety of investigative techniques to work toward a common goal: identification of the decedents, bringing closure to the affected communities. Identification is a complex undertaking; the event (disaster) also can be extraordinarily complex, as it may be an acute event, or one that spans months or years. Compounding this time issue, remains may be heavily fragmented, dispersed, commingled, or otherwise disrupted by either the perpetrators or the disaster itself. To help solve these complexities, we explore the use of stable isotope analysis (SIA) in DVI events. SIA can be used with a variety of body tissues (hair, nail, bone, and teeth), and each represents different time depths in a decedent's life. Bone collagen and tooth enamel carbonate are useful to reconstruct an individual's diet and source water intakes, respectively, leading to likely population or geographic origin determinations. Additionally, the carbon and nitrogen isotopic signatures of bone collagen have calculated intraperson ranges. These facts allow investigators to determine likely origin of remains using isotopic data and can be used to link skeletal elements (to an individual), or perhaps more importantly, show that remains are not linked. Application of SIA can thus speed remains identification by eliminating individuals from short lists for identification, linking or decoupling remains, and reducing the need for some DNA testing. These strategies and hypothesis tests should commence early in the DVI process to achieve maximum effectiveness. [ABSTRACT FROM AUTHOR]

The realm of analytical chemistry continues to struggle with defining and evaluating the limit of detection in analytical methods in the sense that a multitude of definitions, criteria, caveats, and methods have been proposed, developed, and adopted across disciplines. The last decade has seen a surge in the growth of electrochemical methods and studies in the field of forensic science and forensic chemistry. While many disciplines within forensic science have established method validation guidelines, the historical and current lack of electrochemical methods within forensic laboratories throughout the United States has left a major gap in knowledge, inhibiting the adoption and utilization of electrochemistry, which may serve as a powerful tool in many subdisciplines of forensics. As such, this work begins this discussion by focusing first on the limit of detection (LOD), with application toward both qualitative and quantitative methods. Both inorganic (ferrocyanide and lead) and organic (diphenylamine, naltrexone, and acetaminophen) target analytes were analyzed via two common voltammetry methods: cyclic voltammetry and square-wave voltammetry. The LOD for each analyte was estimated and/or calculated following a variety of literature-described methods and compared. The accuracy and reliability of these LOD characteristics based on the experimental data is described herein along with suggestions and recommendations. This manuscript is intended to compare the resulting LOD values from various methods and provide a starting point for the incorporation of electrochemistry into the forensic science laboratory, beginning a focused discussion on the development of validation guidelines and parameters needed for the adoption of this technology in forensic laboratories in order to meet the standards required by the criminal justice system. [ABSTRACT FROM AUTHOR]

This article provides an overview of the status of analytical chemistry education worldwide. The International Union of Pure and Applied Chemistry (IUPAC) has funded a project to assess the state of analytical chemistry education due to concerns about its declining professional status. The article discusses the challenges of conducting a survey on this topic due to the different terminologies and curricular systems used globally. It also examines how analytical chemistry is incorporated into the curricula of several countries, including Australia, Germany, Peru, South Africa, the United Kingdom, and the United States. The educational systems vary in terms of structure, requirements, and hours dedicated to analytical chemistry. The article emphasizes the importance of employers considering the diverse skills and backgrounds of graduates in this field. [Extracted from the article]

The Tennessee Bureau of Investigation (TBI) serves all 95 counties of Tennessee, but the data included in this article are primarily focused in Upper East and East Tennessee (the parts of the state included in the eastern time zone). The forensic chemistry (seized drug) unit of the TBI began reporting nitazene analogues in late 2019. The primary analogues found in forensic chemistry cases were isotonitazene and metonitazene. After discussion and review of reporting statistics, the forensic toxicology unit began to monitor for these compounds in toxicology samples by using ion characteristics with the nitazene analogues. Between March 2021 and December 2023, TBI toxicology received 49,639 cases statewide. Of those, 20,105 (40.5%) received toxicology testing. Approximately 95% of TBI toxicology cases are related to Driving Under the Influence (DUI)/motor vehicle–related incidents. Fatal overdoses and cases from the medical examiner office comprise <5% of TBI toxicology caseload. The toxicology section utilizes the SCIEX 3200 Qtrap with a SCIEX Exion LC AC autosampler system to monitor multiple reaction monitoring transition of nitazene analogues. The ion monitoring for two nitazene analogues, isotonitazene and metonitazene, started in March 2021. Ion monitoring should not be construed as a confirmed result but rather as an indication that a drug may be present. A comparison of this data from the forensic toxicology and forensic chemistry units revealed the rise of new drugs that required a more in-depth review to understand the magnitude and scope. This article is also intended to encourage collaboration between forensic toxicology and forensic chemistry (seized drug) units. [ABSTRACT FROM AUTHOR]

Forensic chemistry plays a crucial role in aiding law enforcement investigations by applying analytical techniques for the analysis of evidence. While bloodstains are frequently encountered at crime scenes, distinguishing between peripheral and menstrual bloodstains presents a challenge. This is due to their similar appearance post-drying. Raman spectroscopy has emerged as a promising technique capable of discriminating between the two types of bloodstains, offering invaluable probative information. Moreover, estimating the time since deposition (TSD) of bloodstains aids in crime scene reconstruction and prioritizing what evidence to collect. Despite extensive research focusing on TSD estimations, primarily in peripheral bloodstains, a crucial gap exists in determining the TSD of menstrual bloodstains. This study demonstrates how Raman spectroscopy effectively analyzes biological samples like menstrual blood, showing similar aging patterns to those of peripheral blood and provides proof-of-concept models for determining the TSD of menstrual blood. While this work shows promising results for creating a universal model for bloodstain age determination, further testing with more donors needs to be conducted before the implementation of this method into forensic practice. [ABSTRACT FROM AUTHOR]

Opioids are a class of drugs used to treat moderate to severe pain and have short-term adverse effects. Nevertheless, they are considered necessary for pain management. However, well-known hazards are connected with an opioid prescription, such as overuse, addiction, and overdose deaths. For example, the death rate from opioid analgesic poisoning in the USA approximately doubled, owing to the overuse and addiction of opioid analgesics. Also, opioids are a very important group of analytes in forensic chemistry, so it is necessary to use reliable, fast, and sensitive analytical tools to determine opioid analgesics. This review focuses on the opioid overdose crisis, the properties of commonly used opioid drugs, their mechanism, effects, and some chromatographic and spectroscopic detection methods are explained briefly. Then most essentially recent developments covering the last ten years in the sensitive electrochemical methods of common opioid analgesics, their innovations and features, and future research directions are presented. [ABSTRACT FROM AUTHOR]

Abstract Synthetic cocaine analogs are designer drugs that recently emerged as non‐controlled substitutes for their parent drug. Among them, nitracaine is of particular concern for its psychoactive effect. In this work, we present a thorough characterization of the electrochemical behavior of nitracaine, with a final quantification performed by differential pulse voltammetry (DPV) in ethanol/lithium perchlorate 0.1 M. The selectivity of the method and reproducibility of results were assessed. LOQ of 0.3 μg mL−1 and a linear dynamic range of up to 400 μg mL−1 were obtained. In addition, recoveries from 85 % to 101 % were achieved on both simulated and real samples. For nitracaine analysis in urine, a clean‐up and a preconcentration step by solid phase extraction (SPE) using the adsorbent Florisil have been developed and optimized through the Design of Experiments (DoE) strategy, thus achieving an enrichment factor of 20.

The area of forensic chemistry has been growing and developing as a line of research due to the high demands of public safety that require increasingly reliable results due to their importance in criminalistics. In this way, the development of new technologies that help this area, whether in the identification and quantification of drugs or the fight against fraud, becomes promising. In this context, the present work explored the production of reference standards from the purification of cocaine/crack samples seized by the Civil Police of the State of Espírito Santo. Cocaine was purified using chromatographic techniques, and benzoylecgonine was synthesized from purified cocaine. All substances were characterized by ultra-high-resolution mass spectrometry and nuclear magnetic resonance. Homogeneity and stability studies were also performed with benzoylecgonine, and the results were evaluated using analysis of variance (ANOVA). Cocaine and benzoylecgonine showed purities of 98.37% and 96.34%, respectively. The homogeneity of the batch, short-term stability, and other parameters were also evaluated, which together indicate this proposal as promising in the development of reference standards for drugs of abuse from samples seized by the Brazilian forensic police. [ABSTRACT FROM AUTHOR]

Introduction: The concentration of heroin in street drugs is highly uncertain. This uncertainty of drug purity is the major cause of overdose. If it is used with a combination of other drugs, it can be fatal. The route of administration and drug tolerance is also important in this prospect. Case presentation: This article represents a case study, in which the person was found dead in a hotel room. During the investigation by the Law Enforcement agencies, two pieces of forensic evidence, i.e., currency notes, cigarette butts and postmortem specimens were submitted to the author’s laboratory for investigation about the cause of death. The aliquot from pieces of evidence was analyzed using a gas chromatography-mass spectrometer (GC-MS), gas chromatography-flame ionization detector (GC-FID), and FTIR. Discussion & conclusions: The GC-MS analysis showed a high concentration of heroin along with dextromethorphan and phenobarbital on currency notes, while analysis of cigarette butts showed the presence of phenobarbital mixed with cannabis constituents in Tobacco leaves. The purity of the heroin sample was found to be 65.5 %. Toxicological analysis of postmortem blood sample showed above the lethal levels of morphine (0.619 mg/L). Moreover, the synergistic effects of the other drugs may have caused the morbidity of the victim.

Abstract Background The beginning of chemometrics within pattern recognition of the 1960s and 1970s is defined. This article shows a comprehensive deliberation on application of the chemometric techniques to chemical data analysis. Main body of the abstract Many review papers along with the usage of chemometrics in forensic chemistry have been available. The present article has been distributed into several parts which comprise chemometrics, its history, its function and chemometrics methods. Conclusion It is advised that these new chemometrics methods should be applied in forensic chemistry to get accurate and fast results.

This document is a special issue of the International Journal of Molecular Sciences that focuses on the analysis and applications of mass spectra in biochemistry. It discusses the definitions of analytical chemistry and how it applies to mass spectrometry, highlighting the use of soft ionization methods as the gold standard in analytical practice. The document explores advancements in high-resolution mass analyzers and their impact on various research fields. It also mentions the importance of isotopomers in fields like medicine, ecology, geology, and forensic anthropology. The article concludes by discussing the diverse applications of mass spectrometry, including direct analysis, imaging techniques, monitoring chemical reactions, and determining kinetics and thermodynamics of chemicals. The text also mentions the use of computational quantum chemistry methods and other instrumental techniques for studying molecular structures. The Special Issue aims to provide innovative developments in mass spectrometry for researchers in different disciplines. [Extracted from the article]

Stand‐off Raman spectroscopy combined with chemometrics was demonstrated to have great potential for detecting and identifying biological stains from a distance for forensic purposes. Bloodstain spectra were collected using a handheld Raman spectrometer equipped with a stand‐off attachment and compared with spectra acquired with a benchtop Raman microscope. The two sets of spectra were visually similar, supporting the potential use of a handheld Raman spectrometer with stand‐off attachment for blood detection at the scene of crime. In addition, the stand‐off Raman spectra of bloodstains were correctly identified using a previously built SVM‐DA model for the identification of all main body fluids (Muro et al., Forensic Chemistry, 2016). Stand‐off Raman spectroscopy opens a new potential opportunity for further development of Raman spectroscopy as a universal tool for detecting and identifying body fluid traces for forensic purposes. [ABSTRACT FROM AUTHOR]

The opium poppy (Papaver somniferum) is a global commercial crop that has been historically valued for both medicinal and culinary purposes. Naturally occurring opium alkaloids including morphine, codeine, thebaine, noscapine, and papaverine are found primarily in the latex produced by the plant. If the plant is allowed to fully mature, poppy seeds that do not contain the opium alkaloids will form within the pods and may be used in the food industry. It is possible for the seeds to become contaminated with alkaloids by the latex during harvesting, posing a potential health risk for consumers. In the USA, there have been more than 600 reported adverse events including 19 fatalities that may be linked to the consumption of a contaminated poppy-containing product such as home-brewed poppy seed tea. Unwashed poppy seeds and pods may be purchased over the Internet and shipped worldwide. The Forensic Chemistry Center, US Food and Drug Administration (FDA) has evaluated several mass spectrometers (MS) capable of rapid screening to be used for high-throughput analysis of samples such as poppy seeds. These include a direct analysis in real-time (DART) ambient ionization source coupled to a single-quadrupole MS, an atmospheric solids analysis probe (ASAP) ionization source coupled to the same MS, and ion mobility spectrometers (IMS). These instruments have been used to analyze 17 poppy seed samples for the presence of alkaloids, and the results were compared to data obtained using liquid chromatography with mass spectral detection (LC–MS/MS). Results from the 17 poppy seed samples indicate that the DART-MS, ASAP-MS, and IMS devices detect many of the same alkaloids confirmed during the LC–MS/MS analyses, although both the false-positive and false-negative rates are higher, possibly due to the non-homogeneity of the samples and the lack of chromatographic separation. [ABSTRACT FROM AUTHOR]

The Fundão Dam breach on 5 November 2015 (the "Event") released tailings, water, soil and/or sediments, and other debris to downstream watercourses. This breach included both direct and indirect impacts from scouring of soils and sediments along and within the affected courses. Multivariate statistical techniques were used to determine the potential of fingerprinting the impact of the breach compared to pre‐Event water quality conditions and unaffected watercourses. The selection of key parameters is an important first step for multivariate analyses. Analysis of too many parameters can mask important trends and relationships, while analysis of too few may miss significant water quality indicators. A two‐phased selection process was used to identify key parameters that indicated impact from the Event: (a) unbiased, principal component analysis to extract chemically dominant profiles among all measured parameters and (b) comparison of metals' concentrations between unaffected soils and/or sediments and tailings samples. Radar charts of key parameters along with statistical comparisons to pre‐Event and not‐affected waterways were then aggregated over space and time to assess impact and potential recovery to pre‐Event conditions. Nine parameters were identified that characterize tailings‐related (direct) and background soil and/or sediment‐related (indirect) impacts. Spatially and temporally aggregated radar charts and nonparametric Mann–Whitney U tests were used to assess the statistical significance of these impacts during each wet season since the breach. Indirect parameters, like aluminum and lead, returned to pre‐Event levels in the first wet season after the Event. By the 2018/2019 wet season, most of the direct and indirect parameters had returned to pre‐Event levels. Integr Environ Assess Manag 2024;20:133–147. © 2023 NewFields Companies, LLC. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). [ABSTRACT FROM AUTHOR]

Background: The beginning of chemometrics within pattern recognition of the 1960s and 1970s is defined. This article shows a comprehensive deliberation on application of the chemometric techniques to chemical data analysis. Many review papers along with the usage of chemometrics in forensic chemistry have been available. The present article has been distributed into several parts which comprise chemometrics, its history, its function and chemometrics methods. Conclusion: It is advised that these new chemometrics methods should be applied in forensic chemistry to get accurate and fast results. [ABSTRACT FROM AUTHOR]

Chirality is a critical issue in pharmaceutics, forensic chemistry, therapeutic drug monitoring, doping control, toxicology, or environmental investigations as enantiomers of a chiral compound can exhibit different activities, i.e., one enantiomer can have the desired effect while the other one can be inactive or even toxic. To monitor enantioselective metabolism or toxicokinetic/toxicodynamic mechanisms in extremely low content in biological or environmental matrices, sample preparation is vital. The present review describes current status of development of liquid-phase microextraction approaches such as hollow fiber liquid-phase microextraction (HF-LPME), electromembrane extraction (EME), dispersive liquid-liquid microextraction (DLLME), and supramolecular solvent-based microextraction (SSME), used for sample preparation of enantiomers/chiral compounds. The advantages and limitations of the above techniques are discussed. Attention is also focused on chiral separation approaches commonly applied to study the stereo-selective metabolism or toxicokinetic/toxicodynamic mechanisms of enantiomers in the biological and environmental samples. [ABSTRACT FROM AUTHOR]

With growing environmental concern and supply chain uncertainty, now is a fitting time to re-evaluate solvent-free methodologies in forensic chemistry processes. Here, this paper reviews solvent-free approaches for fingermark visualisation, including chemical fuming and vapour phase treatments, dry-transfer treatments, application of heat, and thermal paper specific treatments. After providing historical context, three objectives have been emphasised: identify feasible scenarios for implementing solvent-free methods; showcase the effectiveness of solvent-free methods relative to their nearest solution-based equivalent; and estimate the technological readiness level of each method discussed. Having reviewed the literature, dry-transfer methods of developing latent fingermarks on paper were found to be the most promising and feasible solvent-free approaches for near-term implementation. Such methods make use of standard materials and equipment commonly found in forensic laboratories, are effective at fingermark visualisation, and mitigate most of the pressing issues pertaining to environmental concern and solvent scarcity. [ABSTRACT FROM AUTHOR]

The article discusses the signs of artificial and natural aging of documents under the influence of temperature and humidity changes. It is shown that the use of technologies for artificial aging of documents can create risks of concealing malfeasance, leading to economic, technological damage and health. Methods for detecting signs of artificial aging and the possibility of using physicochemical methods of analysis to detect falsification are discussed. [ABSTRACT FROM AUTHOR]

The mass production of polymers has forced forensic practitioners to reconsider traditional methods of traces analysis. The field of impression reconstruction, specifically markings in firearms, is a prime example. This overview offers a critical evaluation of the relevant published techniques for the reconstruction of serial number in polymers, which include destructive methods such as swelling, heat treatments and relief polishing as well as methods allowing for trace preservation, such as hyperspectral Raman imaging combined with multivariate statistical analysis for enhanced pertinent data extraction. It therefore provides a complementary compilation to existing protocols for metal substrates. The novelty of this work lies within its approach, specifically by establishing not only the mechanistic scientific explanation for suitable comprehension and application of the techniques, but also by properly assessing their relevance considering the use in a forensic science context. The potential of wide‐field imaging techniques, mainly auto‐fluorescence analysis, is suggested for faster acquisition and reduced data processing (i.e., decreased time and greater accessibility). Additionally, application of the acquired knowledge to other relevant forensic traces, such as failure analysis of 3D printed objects, is proposed. Emphasis is also placed on the relevance of a purposeful interpretative framework necessary to reconstruct the singular past of the obliterated serial number thus leading to the identification of the given object in which it is affixed. This article is categorized under:Forensic Chemistry and Trace Evidence > Fingermarks and Other MarksForensic Chemistry and Trace Evidence > Emerging Technologies and MethodsForensic Chemistry and Trace Evidence > Trace Evidence [ABSTRACT FROM AUTHOR]

Water contamination is a growing concern in society. New environmental laws are being enacted to define intolerable human activities, and their enforcement is increasingly supported by forensic science. However, water contamination is a broader security issue that is not only caused by illegal human behavior. Risk‐based approaches are needed to prevent (re)occurrence of incidents and minimize their negative consequences. This can be achieved through the formalization of a monitoring process producing intelligence (i.e., actionable knowledge), crucial to detect recurring incidents, and guiding decision‐makers in their choice of preventive and responsive actions. In this perspective, forensic science has a key role to play in integrating vestiges from water‐contaminating activities (i.e., traces) in such a problem‐solving process. Information conveyed by traces allows detecting similarities among contamination events (i.e., patterns), inferring common causes, and better understanding of mechanisms and consequences of water contamination. The different stages of the process will be described and illustrated through a real case example. Current barriers to the implementation of such a process are then discussed, showing how systemic issues and complexity may prevent the establishment of links across contamination events, thus negatively impacting the generation of intelligence. To overcome these obstacles, we underline the importance to initiate local and size‐limited approaches by implementing relatively simple and flexible systems. New knowledge can be used to improve local situations and help stakeholders to understand the benefits of such a process; then, by a bottom‐up iterative learning process, the approach can be given a greater ambition at a larger scale. This article is categorized under:Forensic Science in Action/Crime Scene Investigation > Special Situations and InvestigationsCrime Scene Investigation > From Traces to Intelligence and EvidenceForensic Chemistry and Trace Evidence > Forensic Food and Environment Analysis [ABSTRACT FROM AUTHOR]

Forensic chemistry plays a pivotal role in modern criminal investigations, providing invaluable insights into a diverse array of evidentiary materials. This review article offers a general exploration of a few key facets within the realm of forensic chemistry, encompassing fingerprint analysis, and biological fluid assessment. Each of these domains contributes to the intricate puzzle of forensic investigations. In this review, fingerprint analysis serves as a cornerstone in identifying individuals, with advancements in fingerprint development techniques enhancing the accuracy and reliability of identification. The analysis of seized drug samples offers crucial insights into the crime scene and gives vital clues as to which drug of abuse is responsible for the crime, in essence, this review amalgamates the multifaceted contributions of forensic chemistry, showcasing its pivotal role in unraveling complex criminal scenarios. [ABSTRACT FROM AUTHOR]

Certified reference materials (CRM) of amphetamine derivatives were produced through a simple, rapid and efficient synthesis in both batch and continuous‐flow conditions, accompanied by the development of a comprehensive certification protocol for this class of substances. Our chemistry enabled the synthesis of MDA, MDMA, PMA and PMMA in two steps from safrole and estragole with overall yields of 38–61 % in 48 hours under batch conditions and 61–65 % in 65 minutes under continuous‐flow conditions, followed by the development of a certification protocol for these materials through identity checking, homogeneity, stability, and characterization studies. Furthermore, as result of this work, a very pure CRM of MDA.HCl with 99.1±1.4 g/100 g of certified characterization value was produced. Considering the importance of supplying amphetamine calibrants for public security efforts in Forensic Chemistry, the potential therapeutical applications, and responding to the rising demand for the synthesis of CRM, this work presents a pioneering approach for the production of amphetamine and related compounds. [ABSTRACT FROM AUTHOR]

Over the past decade, new challenges in seized drug analysis have pushed the limits of existing instrumentation and workflows. These challenges include increasing caseloads, complex samples containing previously unidentified substances, and evolving legal requirements. Traditional approaches to seized drug analysis—such as gas chromatography mass spectrometry, color tests, and Fourier transform infrared spectroscopy—can be insufficient for current challenges, motivating the community to explore new instrumentation or data analysis solutions. However, the road to validation, implementation, and adoption of new technologies and solutions can be arduous. In this overview, we discuss the major challenges facing the seized drug community that can be addressed by advances in analytical approaches and highlight some emerging techniques that have been or could be adopted by laboratories in the near‐term. We also discuss specific hurdles limiting the implementation and adoption of new techniques, and approaches to lower these barriers. This article is categorized under:Forensic Chemistry and Trace Evidence > Controlled and Emerging Drug CompoundsForensic Chemistry and Trace Evidence > Emerging Technologies and MethodsForensic Chemistry and Trace Evidence > Presentation and Evaluation of Forensic Science Output [ABSTRACT FROM AUTHOR]

Microorganisms are widespread on the planet being able to adapt, persist, and grow in diverse environments, either rich in nutrient sources or under harsh conditions. The comprehension of the interaction between microorganisms and drugs is relevant for forensic toxicology and forensic chemistry, elucidating potential pathways of microbial metabolism and their implications. Considering the described scenario, this paper aims to provide a comprehensive and critical review of the state of the art of interactions amongst microorganisms and common drugs of abuse. Additionally, other drugs of forensic interest are briefly discussed. This paper outlines the importance of this area of investigation, covering the intersections between forensic microbiology, forensic chemistry, and forensic toxicology applied to drugs of abuse, and it also highlights research potentialities. Key points Microorganisms are widespread on the planet and grow in a myriad of environments. Microorganisms can often be found in matrices of forensic interest. Drugs can be metabolized or produced (e.g. ethanol) by microorganisms. [ABSTRACT FROM AUTHOR]

Forensic chemistry, by the analytical equipment that it owns and by its working methods it has created and is still creating according to its needs, continues to bring a significant contribution to the resolution of various investigative cases of the criminal investigation bodies. In some cases, however, after the efforts of performing the activities to analyze and identify the substances in question, legal issues also arise. Thus, the criminal investigation body wants to know if the identified substances belong to the category of dangerous/toxic substances or if they are subject to specific laws. In both cases, it is the duty only of the criminal investigation body that ordered the expertise to own the entire legislation in the field that concerns the case, so that the only information the forensic chemist has to give is the name of the identified substances. Except that there is a special field, created by the law no. 194/2011 on combating operations with products likely to have psychoactive effects, other than those listed by normative acts in force. In this case, there is no list of substances regulated by this law, and so it is the forensic chemist who has to evaluate the biological properties of those substances, properties provided by scientific articles or by local or foreign institutions, in order to conclude whether or not a substance is subject to this law. This article describes the existence of some legal commercial products, currently used in the food industry, but which can be diverted to create a state of euphoria, with psychoactive effects. [ABSTRACT FROM AUTHOR]

Fingerprint detection is still the primary investigative technique for deciphering criminal inquiries and identifying individuals. The main forensic fingerprinting reagents (FFRs) currently in use can require multiple treatment steps to produce fingerprints of sufficient quality. Therefore, the development of new, more effective FFRs that require minimal chemical treatment is of great interest in forensic chemistry. In this work, prudently crafted density functional theory and time-dependent density functional theory calculations are utilized to derive mechanistic insight into the optical activity of the non-fluorescent product of ninhydrin, diketohydrindylidenediketohydrindamine (DYDA), and fluorescent product of DFO (1,8-diazafluoren-9-one). We investigate various protonation sites to gain an understanding of isomeric preference in the solid-state material. A relaxed scan of a single torsion angle rotation in the S1 minimized geometry of the O-protonated DYDA isomer suggests a conical intersection upon ∼10° rotation. We show that the absence of a rigid hydrogen-bonded network in the crystal structure of DYDA supports the hypothesis of torsion rotation, which leads de-excitation to occur readily. Conversely, for the fluorescent DFO product, our calculations support an avoided crossing suggestive of a non-radiative mechanism when the torsion angle is rotated by about ∼100°. This mechanistic insight concurs with experimental observations of fluorescence activity in DFO and may aid the photophysical understanding of poorly visualized fingerprints due to weak fluorescence. We show that identifying suggestive avoided crossings via the method described here can be used to initialize thoughts toward the computational design of FFRs. [ABSTRACT FROM AUTHOR]

The characterization of firearm discharge residue (FDR) as a piece of evidence plays an essential role in interpreting the forensic cases involving the use of firearms, such as robberies, murders, suicides, and serious attacks. In the last decade, modern or non-toxic primers have emerged due to environmental issues. Forensic examination of gunshot residue (GSR) has become challenging as primer compositions now vary greatly. The goal of this paper is to provide the elemental profiling of both toxic and lead-free cartridge primers available in the Turkish ammunition market. Inductively coupled plasma-mass spectrometry (ICP-MS), scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) were used in this investigation. Multivariate statistical methodologies such as principal component analysis (PCA) and Pearson's correlation coefficient (PCC) analysis were used to interpret the elemental profile data determined in the residue generated after ignition of the cartridge primers. Three components were observed: Ba-Sb-Pb-Cu-Gd, Ti-Sr-Zn, and Al-Ca-Ga, which is also consistent with the PCC analysis. SEM-EDS was employed to confirm the existence of GSR particles. The binding energies, determined using XPS, indicated the chemical state assignments in samples such as Pb(NO3)2, Sb2S3, Ba(NO3)2, CuO, ZnO and MoS2. This research will improve the robustness of the interpretation of GSR-related evidence. [ABSTRACT FROM AUTHOR]

Cannabis is recorded to be the most used drug in the world. This causes a lot of difficulties for developing countries to curb the illegal cultivation, sale, and use of cannabis. The main psychoactive component of the cannabis plant is D9‐tetrahydrocannabinol (THC). The introduction of mobile forensic labs has greatly increased the testing efficiency of psychotropic substances, but the traditional methods of analysis might seem to be cumbersome for the individual experimenting with the scene of seizure. The incorporation of portable analytical devices in forensic field analysis is the approach in the right direction for the testing of drugs. In this paper, we introduce a paper‐based microfluidic device for the onsite detection of marijuana. The device comprises the fast blue B reagent (FBB) as the main reagent. The µPAD was used for the successful detection of seized marijuana. The µPAD‐based detection was combined with a UV‐Vis spectroscopic confirmation. The computational modeling of the absorbance spectra gave further insights into the product formation during the reaction of THC and FBB. This novel method helps in a faster analysis of marijuana, at a considerably lower cost; which is a great boost to the forensic community and the law enforcement authority. [ABSTRACT FROM AUTHOR]

Reports related to incidences of drug facilitated crimes (DFCs) have notably increased in recently. In such cases, victims report being assaulted or robbed while under the influence of drugs. Lorazepam (LZ) is frequently used in DFCs as it can easily make victims docile owing to its potent numbing effect. Therefore, a straightforward and green analytical method to analyze LZ in spiked food matrices in connection with criminal acts becomes important. The current study reports a simple, green, and high sample throughput analytical method for determining LZ in food and drink matrices commonly encountered in DFCs, based on recently introduced cellulose paper sorptive extraction (CPSE). For the extraction of LZ from food matrices, pristine cellulose paper (CP, commonly used laboratory filter paper) was used as a sorptive medium. Five pieces of CP (1.5″ × 1.5″ each) were dipped into diluted food matrices (cream biscuits and tea) and stirred on a rotary shaker for 30 min at 200 rpm. The CPs were then dried, and the adsorbed LZ was back-extracted into 2 mL of methanol. The extract was then subjected to GC–MS analysis in selected ion monitoring (SIM) mode. Several parameters, including CP size and number, back-extraction solvent type and volume, sample volume, extraction time and stirring speed, pH, ionic strength, elution time and speed, were thoroughly screened and optimized. Under the optimized conditions, the method was found to be linear in the range of 0.2–10 µg·mL−1 (or µg·g−1) with a coefficient of determination (R2) ranging from 0.996–0.998. The limit of detection and limit of quantification for cream biscuits were 0.054 and 0.18 µg·g−1 whereas they were 0.05 and 0.16 µg·mL−1 for tea samples. For all measurements, the relative standard deviations (%RSD) were always below 10%. Two mL of methanol per sample was used during the entire sample preparation process. The greenness of the proposed procedure was evaluated using Analytical Eco-Scale and GAPI greenness assessment tools. Finally, the CPSE–GC–MS method has been applied for the determination of LZ in forensic food samples which were used in DFCs. [ABSTRACT FROM AUTHOR]

New psychoactive substances (NPSs) still represent an issue of great concern worldwide despite efforts made by national and international control systems to limit the spread of these substances. Alpha-pyrrolidinohexanophenone (α-PHP) is a fairly recent synthetic cathinone (the second largest group of monitored substances in Europe) with only a few published studies on the substance. Though there is a low incidence of NPS consumption in Portugal, a recent increase in apprehensions and detections in biological matrices of the substance was verified. An analytical methodology was developed and validated for determining and quantitating α-PHP in blood. Solid-phase extraction was employed for sample preparation (500 μL), which was further analyzed by gas chromatography--mass spectrometry-electron ionization in single-ion monitoring mode with cocaine-d3 as the internal standard. Method validation followed the guidelines of the American National Standards Institute/AAFS Standards Board (ANSI/ASB Standard 036). The procedure was linear between 10 and 1,000 ng/mL, with determination coefficients (r 2) higher than 0.999. Carryover was not observed. A limit of detection of 5 ng/mL and a limit of quantitation of 10 ng/mL were achieved. Intraday and intermediate precision and bias assessment showed satisfactory results (coefficient of variation <17.7%; bias <11.6%), and extraction efficiency ranged from 98.5% to 103.3%. The stability of the substance was considered acceptable for at least 6 h at room temperature, 48 h in the autosampler and 21 days after five freeze/thaw cycles. The developed methodology was applied to 15 real samples from the Laboratory of Chemistry and Forensic Toxicology, Centre Branch of the National Institute of Legal Medicine and Forensic Sciences, Portugal, with drug concentrations ranging from 15 to 227 ng/mL. Available information for each case is also detailed in the present article. [ABSTRACT FROM AUTHOR]

Featured Application: This article presents the application of theoretical chemistry methods in forensic sciences as exemplified by LSD and its analogs. These methods allow for the prediction of various types of spectra and spectral assignation, which can be useful for describing novel psychoactive substances. Lysergic acid diethylamide (LSD) and its analogs are commonly encountered substances at crime scenes due to their misuse as hallucinogenic compounds. Modern methods have led to synthesizing different LSD analogs with pronounced physiological effects. Theoretical methods can be a valuable tool for predicting the spectra and stability of novel substances, especially when experimental data are partially available. The current work describes the application of theoretical methods in predicting IR, NMR, UV–VIS, and MS spectra of LSD based on the optimized structure at the M05-2X/6-311++G(d,p) level of theory. A suitable functional has been determined by comparison of the theoretically obtained geometrical parameters with the experimental ones based on the crystallographic structure. The MAE values for the structure optimized at M05-2X/6-311++G(d,p) level of theory were 0.0436 Å (bond lengths) and 2.70° (bond angles). The IR spectra of LSD and LSD tartrate have been described in detail, with the prominent bands being well reproduced (the difference between experimental and theoretical C=O stretching vibration wavenumbers was lower than 11 cm−1). Detailed assignment of 13C NMR spectra led to a high correlation factor (0.999) and low mean absolute error (2.0 ppm) between experimental and theoretical chemical shifts. Optimizing the ground and excited states allowed for the calculation of the energy difference of 330 nm, which reproduced the observed band position in the UV–VIS spectrum of LSD. The most abundant fragments in the experimental mass spectrum (at 323, 221, 207, 181, and 72 m/z) have been optimized, and their stability has been discussed from the structural point of view. This methodology has been validated by comparison with the experimental GC-MS spectra of sample seized at the crime screen and by structure optimization and computation of NMR spectra of common LSD analogs. The theoretical methods for the structure determination and prediction of spectra show great potential in the fast-developing world of new psychedelics. [ABSTRACT FROM AUTHOR]

Favipiravir, a pyrazine analog, is proposed as providential antiviral agent against the COVID-19 infection during 2020 pandemic emergency. For the first time, a fabric phase sorptive extraction (FPSE) combined with gas chromatography-mass spectrometry (GC-MS) has been developed and applied for the determination of favipiravir (FAV) in biological samples (human plasma, blood and urine), pharmaceutical and forensic samples. The method comprises of extraction of FAV by FPSE followed by its derivatization with N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) and GC-MS analysis. Design of experiment-based optimization was performed using Placket-Burman Design (PBD) and Central Composite Design (CCD) for the screening of significant factors of FPSE and their optimization, respectively. Among all tested membranes, sol-gel polyethylene glycol (PEG) has offered the best extraction efficiency for FAV. Under optimum conditions, the proposed method was found to be linear in the range of 0.01–10 µg mL−1 by GC-MS. The LODs and LOQs were as low as 0.001-0.0026 µg mL−1 and 0.003-0.0086 µg mL−1, respectively by GC-MS. Intra-day and inter-day precisions were less than 5 and 10%, respectively, showing good method precision. The proposed method has been successfully applied to detect and quantify FAV in human urine, whole blood and plasma samples along with seized forensic samples. In addition, the proposed method has been evaluated for its green character by ComplexGAPI index.

Zelentsova et al. utilized NMR metabolomic profiling to quantify and compare biomarkers in human serum, aqueous humor (AH), and vitreous humor (VH). SP [ sp [10] SP ] sp They identified promising targets that correlated well with PMI and proposed a model based on several metabolites in AH and VH. Nuclear magnetic resonance (NMR) spectroscopy has a long history in structure elucidation of molecules both small and large. With the reemergence of lower field strength, permanent magnet, benchtop NMR systems operating at 40-100 MHz, there has been a renewed interest in NMR for routine drug analysis as evident in articles discussed in the previous section. In their article " I Benchtop nuclear magnetic resonance spectroscopy in forensic chemistry i ", Draper and McCarney provide an excellent literature review of the use of benchtop NMR systems in forensic chemistry applications largely spanning the last 5 years of developments. SP [ sp [2] SP ] sp This review covers a broad range of methods now being explored to push the application limits of benchtop NMR in forensic as well as other applications. [Extracted from the article]

Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique well known for its ability to elucidate structures and analyse mixtures and its quantitative nature. However, the cost and maintenance of high field NMR instruments prevent its widespread use by forensic chemists. The introduction of benchtop NMR spectrometers to the market operating at 40–80 MHz have a small footprint, are easy to use and cost much less than high field instruments, which makes them well suited to meet the needs of forensic chemists. These modern low field spectrometers are often capable of running multiple nuclei including 1H, 13C, 19F and 31P; 2D NMR experiments and advanced experiments such as solvent suppression and diffusion‐ordered spectroscopy (DOSY) are possible. This has resulted in a number of publications in the area of forensic chemistry using benchtop NMR spectroscopy in the last 5 years that was previously missing from the literature. This mini review summarises this research including examples of benchtop NMR being used to identify and quantify compounds relevant to forensics and some advanced methods that may be used to overcome some of the limitations of these instruments for forensic analysis. Further validation and automation are likely required for widespread uptake of benchtop NMR in industry; however, it has been demonstrated as a useful complement to other analytical techniques commonplace of forensic laboratories. [ABSTRACT FROM AUTHOR]

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Knowledge of opioid tolerance in a deceased person is important for distinguishing between therapeutic and toxic opioid concentrations for that particular individual when interpreting postmortem toxicological results. However, no biomarkers for opioid tolerance are currently available. This review aimed to study the existing literature on mechanisms or changes in signaling pathways related to chronic opioid use, which could be relevant for further studies to identify biomarkers for opioid tolerance. We performed a systematic literature search using the PRISMA 2020 guidelines using the MeSH terms "opioid tolerance AND biomarkers" in PubMed, Embase, WebofScience, and the Cochrane library. A review of the search results yielded seven studies on animal models or humans, identifying and evaluating thirteen possible biomarkers in terms of specificity for changes induced by opioids and other aspects to be considered as potential biomarkers. We evaluated nine potential biomarkers as unlikely to be specific for opioid tolerance, and one had contradictory results in terms of upregulation or downregulation. However, methylation of the promoter region of the μ-opioid receptor gene, increased activity of soluble puromycin-sensitive aminopeptidase, altered miRNA profile, or other multiple component profiling may be interesting to study further as biomarkers for opioid tolerance in forensic postmortem cases. • Biomarkers for opioid tolerance could assist interpretation of postmortem opioid concentrations. • Through a thorough literature review we identified several possible biomarkers. • The majority of identified biomarkers were most likely not specific for opioid tolerance. • Methylation of the μ-opioid receptor gene and activity of soluble puromycin-sensitive aminopeptidase may be interesting. • Altered miRNA profile, or other multiple component profiling may be interesting to study further as well. [ABSTRACT FROM AUTHOR]

[Display omitted] • We optimized a RP-HPLC-DAD-HRMS method suitable for the simultaneous analysis of acid and basic synthetic organic pigments. • We proved that the optimized method can be translated also to HRMS detection. • We improved the chromatographic separation of natural and synthetic acid dyes. • We paved an ultra-selective and ultra-sensitive analytical strategy able to minimise peak tailing. • We applied the optimized method to the analysis of a contemporary Persian carpet. Acid synthetic organic pigments (SOPs), namely water-soluble anionic compounds containing acidic groups (e.g. −SO 3 H, –NO 2 , etc), were introduced into artistic materials in the late 19th century. SOPs were often combined in highly complex mixtures to achieve the desired colours, and therefore, chemical analysis requires ultra-selective and ultra-sensitive methods such as reversed-phase liquid chromatography coupled with mass spectrometric detectors. However, acid SOPs produce chromatographic tailing, leading to loss of resolution and sensitivity. To improve their detection, in this work an approach based on liquid chromatography coupled to a diode array detector and high-resolution mass spectrometry (HPLC-DAD-HRMS) was optimized. The study was carried out using standard acid SOPs (Amido naphthol red G, Cotton scarlet, and Naphthol yellow S), also assessing the effect of chromatographic parameter modification on a selection of natural dyes (Carminic acid, Alizarin, and Purpurin) and basic SOPs (Methylene blue and Methyl violet). Starting from a chromatographic gradient optimized for the analysis of tannins in iron gall inks, different flow rates and mobile phase modifier (formic acid) concentration were tested. The chromatographic efficiency (number of theoretical plates, NTP), resolution (R), symmetry factor (SF), ionisation efficiency (IE), signal-to-noise ratio (SNR), limit of detection (LOD) and limit of quantification (LOQ) were evaluated for each analyte. This enabled us to determine the optimal chromatographic conditions for the analysis of acid dye-based artistic materials (gradient with water with 1% v/v formic acid (FA); acetonitrile with 0.3% v/v FA; flow rate = 0.6 mL/min). Finally, the optimized method was applied for the investigation of organic dyes in a Persian carpet, and proved effective in improving both sensitivity and selectivity of the target analytes in a complex matrix. This study not only provides us with a chromatographic method that could be universally valid for the analysis of historical and contemporary artistic materials, but also caters to the difficult chromatographic separation of acid dyes in food, environmental, and forensic chemistry. [ABSTRACT FROM AUTHOR]