Ana de Castro

University of Santiago de Compostela | USC · Instituto de Ciencias Forenses "Luís Concheiro"

Hair analysis is a reliable and widely used tool to evaluate drug exposure in many fields, including workplace testing, drug abuse history and withdrawal control, post-mortem toxicology, doping control, therapeutic drug monitoring of pharmaceuticals and even environmental exposure to toxic agents. Compounds incorporated into the hair structure resi...

Synthetic cathinones are new psychoactive substances which act as central nervous system stimulants with mixed sympathomimetic activity. In the last decades, they entered in the drug market as substitutes of traditional drugs and made necessary the development of analytical methods for their determination in different biological samples. Blood and...

The ever-increased usage of cytostatic drugs leads to high risk of exposure among healthcare workers. Moreover, workers are exposed to multiple compounds throughout their lives, leading to cumulative and chronic exposure. Therefore, multianalyte methods are the most suitable for exposure assessment, which minimizes the risks from handling cytostati...

Aim Our aim was to develop and validate a fast, sensitive, and specific method determining 17 designer benzodiazepines (adinazolam, clobazam, clonazolam, delorazepam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, flunitrazolam, N-desmethylclobazam, nifoxipam, nitrazolam, meclonazepam, pyrazolam and zolazepam)...

Aim To provide information about driving under the influence of drugs (DUID) cases in Spain during the last 6 years and to evaluate the impact of the Spanish lockdown (March 14th to May 6th 2020) on drivers’ consumption profile. Method In total, 16,461 oral fluid samples were collected from drivers in Spain that tested positive on the roadside bet...

Aim Objective The purpose of this preliminary study was to assess the utility of applying a non-targeted comprehensive drug screening using High Resolution Mass Spectrometry to a cohort of patients attending the Emergency Department (ED) due to drug intoxication; and to evaluate the differences in toxicological profile between methamphetamine (MAMP...

In recent years, identification and analysis of designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogues of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop a...

Objectives: To detect the presence of unsuspected and/or undeclared cathinone and piperazine-type designer drugs in methamphetamine (METH) and amphetamine users treated in emergency departments, and to compare clinical and toxicologic profiles. Material and methods: Retrospective observational study of emergency department patients treated for c...

Therapeutic drug monitoring (TDM) of immunosuppressants is essential to avoid either rejection or toxicity after solid organ transplantations. Capillary microsampling approaches are an outstanding alternative to conventional venous sampling for TDM (easy and non-invasive collection, enabling self-sampling, and cost-saving shipment, processing and s...

New psychoactive substances (NPS) have been introduced into the market in recent years, with new analytes reported every year. The use of these substances in women can occur at any stage of life, even in the childbearing age. Drug use during pregnancy presents significant risks for the mother and the fetus, so it is important to have tools that all...

Hair and nails are keratinized matrices that can be used in Toxicology as matrices for the long-term detection of substances. Whereas hair is an established matrix with decades of use in this field, nails have been less studied, especially including a comparison to hair samples. Specifically in the case of antidepressant and benzodiazepine drugs, v...

The articles included in this collection cover novel analytical approaches, including chromatographic and spectrometric methods, and sample preparation techniques for the investigation and analysis of several classes of compounds. These compounds include novel psychoactive substances (NPS) as well as other drugs and substances within the scope of c...

Purpose: Psychiatric disorders and drugs used for their treatment, can have negative consequences for the pregnancy and the development of the newborn. Therefore, meconium, maternal hair and maternal medical records were compared for the detection of antidepressants and benzodiazepines exposure during pregnancy. Moreover, correlations between neona...

Cannabis consumption has been increasing worldwide among pregnant women. Due to the negative effects of prenatal cannabis exposure, it is necessary to develop an objective, sensitive and specific method to determine cannabinoids use during pregnancy. In this study, we compared four different biological samples, maternal hair, meconium, umbilical co...

Hair has been used for decades in toxicology as a biological matrix for long-term detection of substances. Nails are another keratinized matrix that is being studied as an alternative when hair cannot be obtained. Although cannabis is the most prevalent illicit drug in the world, cannabinoid distribution in nails compared to hair has been scarcely...

Background Early diagnosis of nicotine, ethanol and drug use during pregnancy is critical in order to provide adequate care. Current screening procedures show limitations in terms of reliability and short windows of detection. Objectives To investigate the prevalence and identify biomarkers of substance use and changes in substance use during preg...

Scopolamine is used clinically, but it is also used as a recreational drug and as an incapacitating drug, in sexual crimes and robberies. In this paper, the authors report the case of a woman with a diminished consciousness following an unsuspected overdose with scopolamine and review published articles on scopolamine poisoning that included concen...

The current use and misuse of synthetic and prescription opioids in the US has reached epidemic status. According to the US Department of Health and Human Services, every day more than 130 people in the US die after overdosing on opioids, and 2.1 million had an opioid use disorder in 2018. Hair is becoming an alternative matrix of increasing intere...

Therapeutic drug monitoring (TDM) of immunosuppressants (IMS) is crucial to prevent rejection or toxicity after solid organ transplantation. Microsampling techniques (sampling <50 µL of blood) can be a good alternative to conventional venous sampling for TDM, due to their numerous advantages, including its easy and low-invasive sampling, enabling s...

Nail samples are an alternative to hair for long-term monitoring of drug use, although there are a limited number of studies about its applicability. This study presents the development and validation of a LC-MS/MS method for the determination of five antipsychotic drugs (clozapine, haloperidol, levomepromazine, olanzapine and quetiapine) in nail a...

Introduction: Smoking during pregnancy can have serious obstetric and fetal complications. Therefore, it is essential to identify in utero exposure to tobacco, being meconium the matrix of choice for this purpose. Methods: Meconium (n = 565) was analyzed for nicotine, cotinine and hydroxycotinine by LC–MS-MS. Then, tobacco meconium results were co...

An LC–MS/MS method for the determination of 14 benzodiazepines (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclo...

Aim: This study aimed: to develop and validate an LC–MS/MS method for mycophenolic acid, tacrolimus, sirolimus, everolimus and cyclosporin A in oral fluid (OF), as an essential tool to study the usefulness of OF as an alternative matrix for immunossuppressants’ therapeutic drug monitoring; and to find the best OF collector for these analytes. Mater...

New psychoactive substances have been introduced into the market in the last years due to their unregulated status. Synthetic cathinones are one of their main representatives, and they have shown to produce neonatal complications. It is important to have objective tools to identify in utero exposure to drugs that have shown to produce neonatal comp...

Objective The most common mental diseases in pregnant women are depression and anxiety disorders (estimated prevalence 6.5–12.9% and 15.6%, respectively [1], [2]). The drugs used in their treatment (antidepressants and benzodiazepines) can produce serious obstetric complications, as well as deleterious effects in fetal development and later in lif...

Background: Driving under the influence of drugs (DUID) increases the risk of serious injury or death in traffic accidents. The aim of this study was to provide information about DUID in Spanish drivers. Methods: 10,064 oral fluid samples were collected from Spanish drivers that tested positive on the roadside using the Dräger DrugTest 5000 (DDT500...

Purpose Alcohol exposure during pregnancy constitutes one of the leading preventable causes of birth defects, mental retardation and neurodevelopmental disorders in the exposed children. The ethanol marker ethyl glucuronide (EtG) is a specific long-term marker of ethanol in utero exposure in meconium; however, currently, there are scarce or no data...

Tobacco exposure during pregnancy is associated with obstetric and fetal complications. We developed and validated an LC-MS/MS method to determine nicotine, cotinine and hydroxycotinine (OH-cotinine) in placenta (PL) and umbilical cord (UC). Specimens were homogenized in water, followed by solid phase extraction. Chromatographic separation was perf...

The implementation of the points-based driving license helps to change the drivers' behavior and is related to a reduction of traffic accidents and fatalities. In Spain, when a driver loses all points, the driving license is revoked, so the driver must enroll on a Driver Awareness and Re-education (DARE) course. However, at the moment offenders are...

According to 2014 National Survey on Drug Use and Health, 5.3% of pregnant women smoked marijuana in the past month. This prevalence is expected to increase as a growing number of states and countries are now considering legalization. Although umbilical cord is becoming a useful objective tool to detect in utero drug exposure, currently data about...

Drug exposure during pregnancy constitutes a major legal issue and public health concern. Drug and metabolite determination in biological matrices from mother and newborn is an objective indication of prenatal drug exposure. However, limited data are available regarding the interpretation of these analytical results in terms of window of detection...

Objective The objective of the present communication is to give an overview of the Spanish legal situation with regard to drug detection in drivers. In addition, protocols for roadside drug controls and confirmation analysis in our country will be given. Methods The Spanish participation in RoadSide Test Assessments (ROSITA) and Driving Under the...

Amphetamine-type-stimulants (ATS) are the second most commonly used group of illicit drugs worldwide. However, in the last few years, new psychoactive substances (NPS) with stimulant effects have appeared on the illegal market, which are not detected with traditional analytical methods. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) me...

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and can...

Since the implementation of mandatory drug testing in drivers' oral fluid, several solutions to avoid an onsite positive result can be found on drug users' forums, especially for marijuana, including the use of different mouthwashes. Recently, a product for personal hygiene, Kleaner, has been sold for this purpose. The aims of this study were to as...

Introduction Amphetamine and derivatives are the second most commonly used group of illicit drugs worldwide. However, in the last years new psychoactive substances with stimulant effects have appeared in the illegal market, which are not detected with traditional analytical methods. The aim of this study was to develop and validate a method for the...

The use of molecularly imprinted polymers (MIPs) for solid phase extraction (MISPE) allows a rapid and selective extraction compared with traditional methods. Determination of Δ(9)-tetrahydrocannabinol (THC) and 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH) in oral fluid (OF) and urine was performed using homemade MISPEs for sample cl...

Drug determination in biological matrices from the mother and the newborn is an objective measure of maternal and fetal drug exposure. The aim of this study was to compare maternal hair, meconium, umbilical cord, and placenta for detecting in utero drug exposure to cocaine, opiates, methadone, and amphetamines. Maternal hair, meconium, umbilical co...

Background/objectives: Drug of abuse consumption throughout pregnancy is a serious public health problem and an important economic cost to the health system. The aim of this work was to compare maternal interview and hair analysis to determine drug consumption throughout pregnancy and to study relations among maternal interview, hair results, and...

LC-MS/MS methods for the quantification of morphine, morphine-3-glucuronide, morphine-6-glucuronide, codeine, 6-acetylmorphine, cocaine, benzoylecgonine, ecgonine methyl ester, hydroxybenzoylecgonine, cocaethylene, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), methadone, and 2-ethylidene-1,5-...

Due to the high prescription of antidepressants and their frequent involvement in clinical and forensic intoxications, reliable analytical techniques for identification and quantification of these therapeutic drugs should be available in clinical and toxicological laboratories. Improvements in liquid chromatography-mass spectrometry LC-MS(MS) techn...

The apparent victim in an alleged scopolamine-facilitated sexual assault case requested a toxicological hair analysis. Hair decontamination wash solvents were evaporated and stored until analysis. Hair was incubated with 2 ml of 0.01 M phosphate buffer (pH 8.4), and liquid–liquid extracted. Liquid chromatography–tandem mass spectrometric analysis o...

A method based on in-source collision-induced dissociation (ISCID) liquid chromatography time-of-flight mass spectrometry (LC-TOFMS) and reverse target database search was developed and evaluated for drug screening and confirmation in analytical toxicology context. An established LC-TOFMS screening method, in which identification relies solely on p...

A method based on in-source collision-induced dissociation (ISCID) liquid chromatography time-of-flight mass spectrometry (LC-TOFMS) and reverse target database search was developed and evaluated for drug screening and confirmation in analytical toxicology context. An established LC-TOFMS screening method, in which identification relies solely on p...

A liquid chromatography-tandem mass spectrometry (LC-MSMS) target screening in 50mg hair was developed and fully validated for 35 analytes (Δ9-tetrahidrocannabinol (THC), morphine, 6-acetylmorphine, codeine, methadone, fentanyl, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, benzoylecgonine, cocaine,...

The purpose was to explore methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) umbilical cord disposition, correlate with maternal methadone dose and neonatal outcomes, and evaluate the window of drug detection in umbilical cord of in utero illicit drug exposure. Subjects comprised 19 opioid-dependent pregnant women from 2 clinic...

Few investigations have used placenta as an alternative matrix to detect in utero drug exposure, despite its availability at the time of birth and the large amount of sample. Methadone-maintained opioid-dependent pregnant women provide a unique opportunity to examine the placental disposition of methadone and metabolite [2-ethylidene-1,5-dimethyl-3...

This study reports the development and validation of a method using hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) for the analysis of cocaine and its metabolites benzoylecgonine (BE), ecgonine methyl ester (EME), and cocaethylene (CE) in hair samples. Decontamination was performed as follows: Firstly, the aliq...

A liquid chromatography mass spectrometric selected reaction monitoring mode (SRM) method for methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine, benzoylecgonine (BE), 6-acetylmorphine, morphine and codeine quantification in human umbilical cord was developed and fully validated. Analytes were extracted from homogenized ti...

A validated method for quantifying methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, cocaine, benzoylecgonine, 6-acetylmorphine, morphine, and codeine in human placenta by liquid chromatography-ion trap mass spectrometry is described. Specimens (1 g) were homogenized and subjected to solid-phase extraction. Chromatographic separation wa...

Two methods for the determination of ethylglucuronide (EtG) in urine and in hair have been developed by liquid chromatography- tandem mass spectrometry. These two methods were fully validated, including linearity (0.25-100 microg/mL in urine; 0.05-5 ng/mg in hair; r(2) > 0.99, n = 5), limits of detection (0.1 microg/mL in urine, 0.025 ng/mg in hair...

An LC-MS/MS method using 0.5 ml of oral fluid was developed for the determination of morphine, codeine, 6-monoacetylmorphine, methadone, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, benzoylecgonine, cocaine, delta-9-tetrahydrocannabinol, zolpidem, zopiclone, a...

In this paper, a fast, sensitive and selective LC-MS/MS method is described for the simultaneous determination of amitriptyline, imipramine, clomipramine, fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram and venlafaxine, as well as some of their main metabolites (nortriptyline, desipramine, norclomipramine and norfluoxetine), in oral flu...

A method, using 0.5 mL of urine, was developed for the simultaneous determination of ecgonine methyl ester, benzoylecgonine, morphine, codeine, 6-acetylmorphine, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and d-lyse...

A fast method was designed for the simultaneous determination of amphetamine (A), methamphetamine (MA), PMA, MDA, MDMA, MDEA and MBDB in urine. The drugs were analysed by LC (ESI)-MS/MS, after a simple liquid-liquid extraction in the presence of the deuterated analogues. Reverse phase separation on an Atlantis dC18 Intelligent Speed column was achi...

The aim of this study was to assess the effectiveness of two current on-site oral fluid (OF) drug detection devices (OraLab and Dräger), as part of the Spanish participation in the Roadside Testing Assessment Project (ROSITA Project). The study was done in collaboration with the Spanish Traffic Police, in Galicia (NW Spain), during 2004 and 2005. A...

A rapid, sensitive and fully automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method was developed and validated for the direct analysis of 14 antidepressants and their metabolites in plasma. Integration of the sample extraction and LC separation into a single system permitted direct injection o...

A method, using 0.2 ml of plasma, was designed for the simultaneous determination of morphine, 6-monoacetylmorphine, amphetamine, methamphetamine, MDA, MDMA, MDEA, MBDB, benzoylecgonine and cocaine. The drugs were analysed by LC-MS, after solid phase extraction in the presence of the deuterated analogues. Reversed phase separation on an Atlantis dC...

The problem of the malformed children has concerned the humanity for ever, and this also includes the prenatal exposure to drugs of abuse. Tobacco and alcohol are the most common legal drugs used in pregnancy, and cannabis and cocaine, the most common illegal drugs. The use of drugs has been associated with a wide range of structural malformations,...

A new simple and rapid liquid chromatographic-mass spectrometric technique was designed for the determination of nine benzodiazepines in plasma and oral fluid. Benzodiazepines were extracted from alkalinised spiked and clinical plasma and oral fluid samples using a single step, liquid-liquid extraction procedure with diethyl ether. The chromatograp...

This paper describes the analytical methodology for the determination of MDMA, MDA, MDEA and MBDB in oral fluid. After a liquid-liquid extraction, the analysis was carried out by high performance liquid chromatography (HPLC), with fluorescence detection. The detector wavelength was fixed at 285 nm for excitation and 320 nm for emission. The mobile...

En los últimos años el aumento de publicaciones de aplicaciones de la cromatografía de líquidos acoplada a la espectrometría de masas (LC-MS) en numerosos campos analíticos, incluyendo la toxicología y las ciencias forenses, ha sido verdaderamente espectacular. Este hecho, que no deja de aumentar, se debe probablemente tanto a los avances tecnológi...

La sumisión química, que se puede definir como la administración de sustancias psicoactivas a una persona con fines delictivos, constituye un acto criminal cuya prevalencia, todavía escasa, parece estar en aumento. En el presente trabajo se realiza una revisión de la situación actual del problema, partiendo de los antecedentes, pero con especial én...

El consumo de psicoestimulantes, tales como la anfetamina y derivados (éxtasis), ha experimentado un aumento en España en los últimos años. Así, el número de incautaciones de ¿pastillas¿ ha aumentado un 62,35% entre 2001 (860.000) y 2002 (1.396.000), según datos del Observatorio Español sobre Drogas (OED), situándose la máxima prevalencia del consu...

La Fluoxetina es uno de los representantes de los Inhibidores Selectivos de la Recaptación de Serotonina (ISRS), fármacos de primera elección en la terapia antidepresiva moderna. A pesar de la mayor seguridad con respecto a los antidepresivos clásicos, muchos autores defienden la necesidad de monitorizar sus niveles plasmáticos en determinadas circ...

In the last few years, the increased use of liquid chromatography-mass spectrometry (LC-MS) in various analytical fields, including forensic and clinical toxicology, has been spectacular. At the moment, there is not doubt that LC-MS is competing with Gas Chromatography Mass Spectrometry (GC-MS) for the status of the number one analytical technique...

Sumisión química: epidemiología y claves para su diagnóstico Angelines Cruz-Landeira, Óscar Quintela-Jorge y Manuel López-Rivadulla Servicio de Toxicología Forense. Instituto de Medicina Legal. Facultad de Medicina. Universidad de Santiago de Compostela. Santiago de Compostela. La Coruña. España. El uso de sustancias químicas con el fin de manipul...

A rapid, sensitive and selective liquid chromatography/electrospray mass spectrometry (LC/ES-MS) method was developed for the quantitative determination of the anaesthetic benzodiazepine midazolam (MID) in human saliva and plasma from patients undergoing anesthesia procedures. Biological samples spiked with diazepam-d5, the internal standard, were...

Analysis of Delta(9)tetrahydrocannabinol (Delta(9)THC) and its metabolites in biological samples is of great relevance for forensic purposes. In the case of oral fluid (OF), the analysis should determine Delta(9)THC, whereas in urine, it detects the inactive metabolite tetrahydrocannabinol carboxylic acid (THC-COOH). Most laboratories analyze Delta...

Resumen: En los últimos años el aumento de publicaciones de aplicaciones de la cromatografía de líquidos acoplada a la espectrometríade masas (LC-MS) en numerosos campos analíticos, incluyendo la toxicología y las ciencias forenses, ha sido verdaderamente espectacular. Este hecho, que no deja de aumentar, se debe probablemente tanto a los avances t...