Assessment of potentially hazardous elements in soils of the Boyacá industrial corridor (Colombia) using GIS, multivariate statistical analysis, and geochemical indexes.

In the industrial corridor of Boyacá, Colombia, population growth is accompanied by anthropogenic activities such as industrial operations, vehicle exhaust fumes, mining, smelting, atmospheric deposition, and excessive use of chemical products to promote crop growth. These activities are known to have a significant impact on urban and rural soils, contributing significantly to elevated concentrations of potentially hazardous elements in the environment. This industrial corridor is an area of economic and social development that needs to provide reference information that will allow us to know the state of soil quality to preserve and manage the public and geoenvironmental health of this region. Anthropogenic activities have contributed to the accumulation of potentially hazardous elements in the environment, affecting various levels of life and creating risks with economic and social implications. However, igneous activity or detrital deposition also enriches soils and creates geochemical anomalies in specific locations. In these cases, the identification of potentially hazardous elements involves the determination of likely sources of contamination and their relationship to the geological setting. In this study, the concentrations of As, Cd, Pb, Mn, Fe, Zn, Hg, Cu and Ni were determined in eighty-one soil samples from the Boyacá industrial corridor (Colombia). The sequential trend of the concentrations of potentially hazardous elements was as follows: Fe > Mn > Zn > Ni > Cu> Pb > As > Cd > Hg. Furthermore, the application of spatial analysis criteria in GIS software with multivariate statistical tools and geochemical indices allowed the identification of anthropogenic and geogenic sources. Most of the potentially hazardous elements were found in soils exposed to industrial and agricultural activities, except for iron. This element showed low variability in all samples, regardless of the geological formations. Due to the lack of reference values for potentially hazardous elements in Colombia, the concentrations were compared with the environmental standards of the Environmental Protection Agency (EPA) and the Ecuadorian Ministry of Environment, Water and Ecological Transition (MAE). The results demonstrate the complexity of the soil and represent the first exploratory study of potentially hazardous elements in this industrial corridor. These results are the starting point for the establishment of geochemical background lines in Colombia and for inspection policies for areas where productive activities converge.

Forensic analysis of biological fluid stains on substrates by spectroscopic approaches and chemometrics: A review.

BACKGROUND: Bodily fluid stains are one of the most relevant evidence that can be found at the crime scene as it provides a wealth of information to the investigators. They help to report on the individuals involved in the crime, to check alibis, or to determine the type of crime that has been committed. They appear as stains in different types of substrates, some of them porous, which can interfere in the analysis. The spectroscopy techniques combined with chemometrics are showing increasing potential for their use in the analysis of such samples due to them being fast, sensitive, and non-destructive. FINDINGS: This is a comprehensive review of the studies that used different spectroscopic techniques followed by chemometrics for analysing biological fluid stains on several surfaces, and under various conditions. It focuses on the bodily fluid stains and the most suitable spectroscopic techniques to study forensic scientific problems such as the substrate's characteristics, the influence of ambient conditions, the aging process of the bodily fluids, the presence of animal bodily fluids and non-biological fluids (interfering substances), and the bodily fluid mixtures. The most widely used techniques were Raman spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR). Nonetheless, other non-destructive techniques have been also used, like near infrared hyperspectral imaging (HSI-NIR) or surface enhanced Raman spectroscopy (SERS), among others. This work provides the criteria for the selection of the most promising non-destructive techniques for the effective in situ detection of biological fluid stains at crime scene investigations. SIGNIFICANCE AND NOVELTY: The use of the proper spectroscopic and chemometric approaches on the crime scene is expected to improve the support of forensic sciences to criminal investigations. Evidence may be analysed in a non-destructive manner and kept intact for further analysis. They will also speed up forensic investigations by allowing the selection of relevant samples from occupational ones.

Handwriting Changes in Alzheimer's Disease: A Systematic Review.

BACKGROUND: Handwriting is a complex process involving fine motor skills, kinesthetic components, and several cognitive domains, often impaired by Alzheimer's disease (AD). OBJECTIVE: Provide a systematic review of handwriting changes in AD, highlighting the effects on motor, visuospatial and linguistic features, and to identify new research topics. METHODS: A search was conducted on PubMed, Scopus, and Web of Science to identify studies on AD and handwriting. The review followed PRISMA norms and analyzed 91 articles after screening and final selection. RESULTS: Handwriting is impaired at all levels of the motor-cognitive hierarchy in AD, particularly in text, with higher preservation of signatures. Visuospatial and linguistic features were more affected. Established findings for motor features included higher variability in AD signatures, higher in-air/on-surface time ratio and longer duration in text, longer start time/reaction time, and lower fluency. There were conflicting findings for pressure and velocity in motor features, as well as size, legibility, and pen lifts in general features. For linguistic features, findings were contradictory for error patterns, as well as the association between agraphia and severity of cognitive deficits. CONCLUSIONS: Further re-evaluation studies are needed to clarify the divergent results on motor, general, and linguistic features. There is also a lack of research on the influence of AD on signatures and the effect of AD variants on handwriting. Such research would have an impact on clinical management (e.g., for early detection and patient follow-up using handwriting tasks), or forensic examination aimed at signatory identification.

Crime Light Imaging (CLI): A Novel Sensor for Stand-Off Detection and Localization of Forensic Traces.

Stand-off detection of latent traces avoids the scene alteration that might occur during close inspection by handheld forensic lights. Here, we describe a novel sensor, named Crime Light Imaging (CLI), designed to perform high-resolution photography of targets at a distance of 2-10 m and to visualize some common latent traces. CLI is based on four high-power illumination LEDs and one color CMOS camera with a motorized objective plus frontal filters; the LEDs and camera could be synchronized to obtain short-exposure images weakly dependent on the ambient light. The sensor is integrated into a motorized platform, providing the target scanning and necessary information for 3D scene reconstruction. The whole system is portable and equipped with a user-friendly interface. The preliminary tests of CLI on fingerprints at distance of 7 m showed an excellent image resolution and drastic contrast enhancement under green LED light. At the same distance, a small (1 µL) blood droplet on black tissue was captured by CLI under NIR LED, while a trace from 15 µL semen on white cotton became visible under UV LED illumination. These results represent the first demonstration of true stand-off photography of latent traces, thus opening the way for a completely new approach in crime scene forensic examination.

Drug-Facilitated Sexual Assault: A Systematic Review.

Since the last two decades, the scientific community has made an effort to analyze drug-facilitated sexual assault (DFSA). However, a lack of understanding remains about the DFSA problem, particularly concerning the opportunistic variant. Facing this situation, a systematic review of the term DFSA is carried out from its first appearance in the scientific databases consulted (Web of Science, Scopus, and PubMed) to the current day. The search resulted in 773 publications, reduced to a final study sample composed of 19 articles. Eligible studies for this review had to meet certain inclusion criteria, in addition to providing information on DFSA prevalence, DFSA victim profile, DFSA offender profile, involved drugs, or contextual information about the assault. The results demonstrated that the assailants are men, who mostly know victims before the assault. The victims are young women under 30 years old. Alcohol is the drug involved in most DFSA cases, prevailing a voluntary use. Most assaults occur in private spaces, particularly the aggressors' own homes. Furthermore, there is a detected need for a standard definition of DFSA to allow the different actors involved in dealing with sexual violence to work effectively together, and, at the same time, it is detected that the available studies overrepresent proactive DFSA and underestimate opportunism, the most common modus operandi involved in DFSA cases.

Biofilm formation on polyethylene microplastics and their role as transfer vector of emerging organic pollutants.

Microplastic (MP)-colonizing microorganisms are important links for the potential impacts on environmental, health, and biochemical circulation in various ecosystems but are not yet well understood. In addition, biofilms serve as bioindicators for the evaluation of pollutant effects on ecosystems. This study describes the ability of three polyethylene-type microplastics, white (W-), blue (B-), and fluorescent blue (FB-) MPs, to support microbial colonization of Pseudomonas aeruginosa, the effect of mixed organic contaminants (OCs: amoxicillin, ibuprofen, sertraline, and simazine) on plastic-associated biofilms, and the role of biofilms as transfer vectors of such emerging pollutants. Our results showed that P. aeruginosa had a strong ability to produce biofilms on MPs, although the protein amount of biomass formed on FB-MP was 1.6- and 2.4-fold higher than that on B- and W-MP, respectively. When OCs were present in the culture medium, a decrease in cell viability was observed in the W-MP biofilm (65.0%), although a general impairing effect of OCs on biofilm formation was ruled out. Microbial colonization influenced the ability of MPs to accumulate OCs, which was higher for FB-MP. In particular, the sorption of amoxicillin was lower for all bacterial-colonized MPs than for the bare MPs. Moreover, we analysed oxidative stress production to assess the impact of MPs or MPs/OCs on biofilm development. The exposure of biofilms to OCs induced an adaptive stress response reflected in the upregulation of the katB gene and ROS production, particularly on B- and FB-MP. This study improves our understanding of MP biofilm formation, which modifies the ability of MPs to interact with some organic pollutants. However, such pollutants could hinder microbial colonization through oxidative stress production, and thus, considering the key role of biofilms in biogeochemical cycles or plastic degradation, the co-occurrence of MPs/OCs should be considered to assess the potential risks of MPs in the environment.

Differentiation of blood and environmental interfering stains on substrates by Chemometrics-Assisted ATR FTIR spectroscopy.

Blood is the most common and relevant bodily fluid that can be found in crime scenes. It is critical to correctly identify it, and to be able to differentiate it from other substances that may also appear at the crime scene. In this work, several stains of blood, chocolate, ketchup, and tomato sauce on five different substrates (plywood, metal, gauze, denim, and glass) were analysed by ATR FTIR spectroscopy assisted with orthogonal partial least square-discriminant analysis (OPLS-DA) models. It was possible to differentiate blood from the environmental interfering substances independently of the substrate they were on, and to differentiate bloodstains according to the substrate they were deposited on. These results represent a proof-of-concept that open new horizons to differentiate bloodstains from other interfering substances on common substrates present in crime scenes.

Immobilization of Kluyveromyces lactis ß-Galactosidase on Meso-macroporous Silica: Use of Infrared Spectroscopy to Rationalize the Catalytic Efficiency.

Enzyme immobilization on adequate carriers is a challenging strategy. Understanding the enzyme-carrier interactions and their effects on enzyme conformation and bioactivity is critical. In this study, a meso-macropores silica (MMS) was used to immobilize ß-galactosidase from the yeast Kluyveromyces lactis (ß-gal-KL) by physical adsorption. The bioactivity of the immobilized ß-gal-KL was altered, evidenced by the increased Km , decreased Vmax and kcat , and increased activity at alkaline values. By performing infrared spectroscopy analysis and subsequent secondary structure assessment from the amide I band, the immobilized ß-gal-KL suffered a ß-sheet (∼31-35 %) to α-helix (∼15-19 %) transition with increased turns (∼21-22 %) with respect to the free ß-gal-KL having ∼12 % α-helix, ∼42 % ß-sheet, and ∼17 % turns. These findings led us to correlate the observed bioactivity performance to structural alterations to a non-native conformation. The presented line of thought can lead to a better understanding of the reasons causing bioactivity alterations upon enzyme immobilization.

Forensic intelligence-led prevention of drug-facilitated sexual assaults.

This work explores the potentially broader contribution of forensic science to preventive public health through the proactive view promoted by forensic intelligence. For that purpose, a new working framework is applied as a strategic tool that channelizes forensic intelligence in a more understandable and didactic way for decision-makers, guiding preventive crime processes. Concretely, the implementation of this operational framework focuses on preventing drug-facilitated sexual assaults in the nightlife context. Through a two-stage research scheme, the working framework is used as a study tool for understanding this violent phenomenon and as a strategic thinking and action platform for overcoming it. Forensic intelligence-guided actions significantly enhanced institutional and direct support facing this specific form of sexual violence. Awareness messages targeting potential assailants, witnesses, and victims reached more than half a thousand students from the university and pre-university education through a preventive intervention within the educational system. Moreover, the inter-professional dialogue between forensic science and other health, security, and education disciplines shows the broader proactive role of forensic science beyond the traditional retroactive view limited to courtrooms and intelligence-led policing. This study demonstrates as forensic intelligence becomes applicable for civilians, who participate as decision-makers in intelligence-led preventive processes, anticipating the need for intervention by police and judicial authorities.

An approximation to the identification of contexts, experiences, and profiles of victims of drug-facilitated sexual assaults.

This study advances on overcoming a bias limiting the forensic cases studies of drug-facilitated sexual assaults: a narrow study focus, restricted to assaults affecting young women in leisure contexts related to nightlife, party culture, and dating. A new working framework is applied to analyse data from cases received in the National Institute of Toxicology and Forensic Sciences (Madrid, Spain) over the six years between 2012 and 2017. The work throws light on non-previously described contexts, experiences, and profiles of victims, including domestic cohabitation, labour, education, healthcare, women trafficking, and the daily life of people with intellectual disabilities.

Classification of Various Marijuana Varieties by Raman Microscopy and Chemometrics.

The Raman analysis of marijuana is challenging because of the sample's easy photo-degradation caused by the laser intensity. In this study, optimization of collection parameters and laser focusing on marijuana trichome heads allowed collecting Raman spectra without damaging the samples. The Raman spectra of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) standard cannabinoids were compared with Raman spectra of five different types of marijuana: four Sativa varieties (Amnesia Haze, Amnesia Hy-Pro, Original Amnesia, and Y Griega) and one Indica variety (Black Domina). The results verified the presence of several common spectral bands that are useful for marijuana characterization. Results were corroborated by the quantum chemical simulated Raman spectra of their acid-form (tetrahydrocannabinol acid (THCA), cannabidiol acid (CBDA)) and decarboxylated cannabinoids (THC, CBD, and CBN). A chemometrics-assisted method based on Raman microscopy and OPLS-DA offered good classification among the different marijuana varieties allowing identification of the most significant spectral bands.

Assessment of Volatile Compound Transference through Firefighter Turnout Gear.

There is high concern about the exposure of firefighters to toxic products or carcinogens resulting from combustion during fire interventions. Firefighter turnout gear is designed to protect against immediate fire hazards but not against chemical agents. Additionally, the decontamination of firefighter personal protective equipment remains unresolved. This study evaluated the feasibility of a screening method based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) in combination with chemometrics (cluster analysis, principal component analysis, and linear discriminant analysis) for the assessment of the transference of volatile compounds through turnout gear. To achieve this, firefighter turnout gears exposed to two different fire scenes (with different combustion materials) were directly analyzed. We obtained a spectral fingerprint for turnout gears that were both exposed and non-exposed to fire scenes. The results showed that (i): the contamination of the turnout gears is different depending on the type of fire loading; and (ii) it is possible to determine if the turnout gear is free of volatile compounds. Based on the latest results, we concluded that HS-GC-IMS can be applied as a screening technique to assess the quality of turnout gear prior to a new fire intervention.

Potential of High-Resolution Mass Spectrometry for the Detection of Drugs and Metabolites in Hair: Methoxetamine in a Real Forensic Case.

The analysis of drugs of abuse in hair and other biological matrices of forensic interest requires great selectivity and sensitivity. This is done traditionally through target analysis, with one or more analytical methods, or with different and specific preanalytical phases, and complex procedures performed by the toxicological laboratories, and there is no exception with ketamine-like compounds, such as methoxetamine, a new psychoactive substance whose use has increased in the last decades, and continues to grow quickly year by year. More validated methods of analysis are needed to detect these substances in low concentrations selectively. Reanalyzing the samples of a former case of a polydrug consumer accused of a crime against public health in Spain, five metabolites of methoxetamine (normethoxetamine, O-desmethylmethoxetamine, dehydromethoxetamine, dihydronormethoxetamine and hydroxynormethoxetamine) were tentatively detected using a high-resolution technique, that is, liquid chromatography coupled to high-resolution mass spectrometry (LC-HR-MS-MS). The highest analytical selectivity of LC-HR-MS-MS method together a universal and simpler pretreatment stages has demonstrated to allow faster analysis and more sensitivity than the one performed traditionally at the INTCF laboratories, which was gas chromatography coupled to mass spectrometry.

Gender-based differences in perceptions about sexual violence, equality and drug­facilitated sexual assaults in nightlife contexts. / Diferencias de género en percepciones sobre violencia sexual, igualdad y agresiones sexuales facilitadas por drogas en ocio nocturno.

Sexual violence, including drug-facilitated sexual assaults, is a serious issue that is becoming increasingly common in leisure nightlife contexts. This study provides information about the attitudes and perceptions of Spanish youths towards sexual violence within that setting. The participants were recruited by a snowball sampling scheme. A bivariate analysis was performed to identify possible sociodemographic and nightlife recreational habit factors related to gender. The statistical significance of the differences between the studied variables was assessed using the chi-squared and Fisher's exact tests. Women perceived a low level of personal security, as well as the existence of social perceptions penalizing female more than male drug use, and blaming women for the sexual violence they suffer. Women also recognised less explicit violent behaviours as violence significantly more than men did. Men were more willing to have sexual intercourse with someone unable to express consent because of drugs. In addition, they believed more strongly that sexual assaults take place because of the victim's use of alcohol or other drugs. In a leisure nightlife context, women are prone to perceive a lack of social support for themselves and the feeling of impunity for the perpetrators. Furthermore, numerous misconceptions surround drug-facilitated sexual assaults, with the majority of respondents believing that assaults happen after the surreptitious administration of substances to the victim by an unknown assailant. Moreover, the involvement of alcohol was underestimated. Our findings are useful for designing prevention efforts, demystifying the drug-facilitated sexual assaults and enhancing social support for victims.

La violencia sexual, incluyendo las agresiones sexuales facilitadas por drogas, es un serio problema cada vez más común en los contextos de ocio nocturno. Este trabajo estudia las actitudes y percepciones de la juventud española en torno a la violencia sexual en dicho ámbito. Los participantes se reclutaron mediante muestreo en bola de nieve. Se realizó un análisis bivariado para identificar posibles factores sociodemográficos y de ocio nocturno relacionados con género. La significación estadística de las diferencias entre estas variables se evaluó mediante las pruebas de chi-cuadrado y exacta de Fisher. Las mujeres percibieron un menor nivel de seguridad personal, así como la existencia de percepciones sociales que penalizan en mayor medida el consumo de drogas femenino que el masculino, y que culpabilizan a las mujeres por la violencia que sufren. Además, ellos mostraron mayor disposición a mantener relaciones sexuales con personas incapaces de otorgar su consentimiento debido a los efectos de las drogas. Los hombres creen en mayor medida que las agresiones sexuales ocurren debido al uso de alcohol u otras drogas por parte de las víctimas. En el contexto de ocio nocturno, las mujeres son propensas a percibir la existencia de una falta de apoyo social hacia ellas, así como un sentimiento de impunidad social hacia los agresores. Además, existen numerosas concepciones erróneas en torno a las agresiones sexuales facilitadas por drogas. La mayoría cree que las agresiones ocurren tras la administración encubierta de sustancias a la víctima por parte de un agresor desconocido. Además, se subestimó la participación del alcohol. Nuestros hallazgos son útiles para diseñar esfuerzos preventivos bien dirigidos, desmitificar el fenómeno de las agresiones sexuales facilitadas por drogas y mejorar el apoyo social a las víctimas.

Prevalence study of drugs and new psychoactive substances in hair of ketamine consumers using a methanolic direct extraction prior to high-resolution mass spectrometry.

Few studies have reported the prevalence or incidence about the consumption of new psychoactive substances (NPS). The hair analysis can be useful for this purpose. At the present, ketamine is the most consumed arylcyclohexylamine associated to young consumers and polyconsumption profiles. For this reason, ketamine consumer cases become very interesting to provide information on NPS prevalence. In this work, ten former cases of the National Institute of Toxicology and Forensic Science (INTCF) of Madrid Department (INTCFM), all of them belonging to defendants accused of crimes against public health and who had been found positive to ketamine, were reassessed. At the first toxicological analysis of those hair samples, a positive consume in ketamine had been determined by gas chromatography coupled to mass spectrometry (GC-MS). In this work, the same hair samples were reanalyzed by high-resolution mass spectrometry ( UHPLC-HRMS/MS) using an incubation methanolic extraction combined with a single, simpler, non-selective and direct sample pre-treatment. After corroborating the GC-MS results previously obtained for the same samples, the detection of additional NPS using this new methodology evidenced its benefits and opened the possibility to perform a NPS prevalence study. In brief, in those cases with a positive consumption in ketamine, a polyconsumption of other drugs and NPS was found, including different arylcyclohexylamines as deschloroketamine, 3-MeO-PCP and methoxetamine; and cathinones as methylmetcathinone and N-ethyl-pentylone.

Evaluation of an Ozone Chamber as a Routine Method to Decontaminate Firefighters' PPE.

Ozone chambers have emerged as an alternative method to decontaminate firefighters' Personal Protective Equipment (PPE) from toxic fire residues. This work evaluated the efficiency of using an ozone chamber to clean firefighters' PPE. This was achieved by studying the degradation of pyrene and 9-methylanthracene polycyclic aromatic hydrocarbons (PAHs). The following experiments were performed: (i) insufflating ozone into PAH solutions (homogeneous setup), and (ii) exposing pieces of PPE impregnated with the PAHs to an ozone atmosphere for up to one hour (heterogeneous setup). The ozonolysis products were assessed by Fourier Transform Infrared Spectroscopy (FTIR), Thin-Layer Chromatography (TLC), and Mass Spectrometry (MS) analysis. In the homogeneous experiments, compounds of a higher molecular weight were produced due to the incorporation of oxygen into the PAH structures. Some of these new compounds included 4-oxapyren-5-one (m/z 220) and phenanthrene-4,5-dicarboxaldehyde (m/z 234) from pyrene; or 9-anthracenecarboxaldehyde (m/z 207) and hydroxy-9,10-anthracenedione (m/z 225) from 9-methylanthracene. In the heterogeneous experiments, a lower oxidation was revealed, since no byproducts were detected using FTIR and TLC, but only using MS. However, in both experiments, significant amounts of the original PAHs were still present even after one hour of ozone treatment. Thus, although some partial chemical degradation was observed, the remaining PAH and the new oxygenated-PAH compounds (equally or more toxic than the initial molecules) alerted us of the risks to firefighters' health when using an ozone chamber as a unique decontamination method. These results do not prove the ozone-advertised efficiency of the ozone chambers for decontaminating (degrading the toxic combustion residues into innocuous compounds) firefighters' PPE.

Identification of 2C-B in Hair by UHPLC-HRMS/MS. A Real Forensic Case.

The analysis of drugs of abuse in hair and other biological matrices of forensic interest requires great selectivity and sensitivity. This has been traditionally achieved through target analysis, using one or more analytical methods that include different preanalytical stages, and more complex procedures followed by toxicological laboratories. There is no exception with 2C-series drugs, such as 2C-B, a new psychoactive substance (NPS), which use has emerged and significantly increased, year by year, in the last decades. Continuously new analytical methods are required to selectively detect and identify these new marketed substances at very low concentrations. In this case report, one former case of a polydrug consumer (charged of a crime against public health in Spain) was reanalyzed in hair matrix. In this reanalysis, 2C-B has been positively detected and identified using liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS). The most selective analytical UHPLC-HRMS/MS method alongside a universal and simpler pretreatment methodology has opened up more possibilities for the detection of substances of different chemical structure and optimization of different HRMS/MS detection approaches allowing the identification of 2-CB in the hair of a real forensic case.

Human ultra-weak photon emission as non-invasive spectroscopic tool for diagnosis of internal states - A review.

In the knowledge that human ultra-weak photon emission (UPE) is mainly due to the metabolic oxidative stress processes that the skin cells undergo in the presence of reactive oxygen species (ROS), external stressors (like UV radiation), but also internal stressors (like diseases or brain activity) might strongly influence the UPE. This manuscript revises the scientific advances focused on the influence of internal factors on the human UPE. According to literature, the UPE seems to be influenced by some diseases (including diabetes, hemiparesis, protoporphyria, or a typical cold), and even by the cerebral intention/relaxation (brain activity/meditation). These allow to consider UPE as a natural and promising non-invasive spectroscopic tool for helping during the diagnosis of a variety of illnesses or stress- / mood-state disorders. Nonetheless, further research is required for answering some still unresolved controversial points.

Introducing ATR-FTIR Spectroscopy through Analysis of Acetaminophen Drugs: Practical Lessons for Interdisciplinary and Progressive Learning for Undergraduate Students.

Infrared (IR) spectroscopy is a vibrational spectroscopic technique useful in chemical, pharmaceutical, and forensic sciences. It is essential to identify chemicals for reasons spanning from scientific research and academic practices to quality control in companies. However, in some university degrees, graduate students do not get the proficiency to optimize the experimental parameters to obtain the best IR spectra; to correlate the IR spectral bands with the molecular vibrations (chemical elucidation); to have some criteria for any substance identification (especially relevant in quality control to recognize counterfeit); and to apply chemometrics for comparing, visualizing, and classifying the IR spectra. This work presents an experimental laboratory practice for an introductory teaching of the IR instrumental conditions in the identification of substances based on visual spectra comparison and statistical analysis and matching. Then, the selected IR conditions are applied to different commercial drugs, in the solid state or in solution, mostly composed of acetaminophen. Finally, the students apply chemometrics analysis to the IR data. This practice was designed for the training in a chemistry subject for undergraduate students of the chemistry, pharmacy, or forensics degrees, among others related to science, medical, food, or technological sciences.