Research Progress on Biological Matrix Reference Materials in Forensic Toxicology / 法医学杂志

Biological matrix reference material is a reference material that combines the target material with the biological matrix. The biological matrix reference material has higher consistency with the authentic specimens in forensic toxicology, and its application has a positive effect on improving the accuracy of test results. This paper reviews the research on the matrix reference materials corresponding to three common biological test materials (blood, urine and hair). In order to provide reference for the development and application of biological matrix reference materials in forensic toxicology, this paper mainly introduces the research progress of preparation technology of biological matrix reference materials and some existing products and their parameters evaluation.

Progress in the Application of Magnetic Nanoparticles in Forensic Trace Analysis / 法医学杂志

Given the complexity of biological samples and the trace nature of target materials in forensic trace analysis, a simple and effective method is needed to obtain sufficient target materials from complex substrates. Magnetic nanoparticles (MNPs) have shown a wide range of application value in many research fields, such as biomedicine, drug delivery and separation, due to their unique superparamagnetic properties, stable physical and chemical properties, biocompatibility, small size, high specific surface area and other characteristics. To apply MNPs in the pretreatment of forensic materials, maximize the extraction rate of the target materials, and minimize interference factors to meet the requirements of trace analysis of the target materials, this paper reviews the application of MNPs in the fields of forensic toxicological analysis, environmental forensic science, trace evidence analysis and criminal investigation in recent years, and provides research ideas for the application of MNPs in forensic trace analysis.

Research Progress of Zebrafish Model in Toxicology and Its Application Prospects in Forensic Science / 法医学杂志

In recent years, zebrafish model has been widely concerned and recognized by scholars at home and abroad. As an animal model, zebrafish is of great research value because it is easy to feed, easy to operate, observe and analyze, and the model results can be highly combined with human body test data. Zebrafish model has been widely used in many fields, including basic medical science, clinical medicine, agricultural production, environmental toxicology and forensic science. This review introduces the biological characteristics of zebrafish, summarizes the research progress of zebrafish model in toxicology, and discusses the application prospect of zebrafish model in forensic science.

Mass Spectrometry Imaging and Its Application in Forensic Toxicology / 法医学杂志

Mass spectrometry imaging （MSI） is a new imaging technology that can simultaneously detect and record the spatial distribution information of multiple molecules on the sample surface without labeling. The main principle of MSI is to combine mass spectrometry with imaging technology and irradiate the sample slice with ion beam or laser to ionize the molecules on its surface, obtain the mass spectrometry signal through the detector, convert the obtained data into pixel points by the imaging software, and then construct the spatial distribution image of the target compound on the tissue surface. The sample preparation for MSI include： sample collection and storage, tissue section, tissue pretreatment, selection and application of matrix. At present, this technology has been widely used in the fields of biomedicine, new drug development and proteomics, and its application in the field of forensic toxicology has also gradually attracted attention. This article reviews the principles and sample preparation process of MSI, describes the application of MSI in abused substances and metabolites of various material matrices, herbal mixtures, latent fingerprints, hair and animal and plant tissues, and discusses the prospects of the application of this technology in forensic toxicology, in order to provide ideas and references for the application of MSI technology in forensic toxicology.

Research Progress of Metabolomics in Forensic Pathology / 法医学杂志

Metabolomics is an interdisciplinary subject that rose in the post-genomic era, which focuses on quantitative study of the response of living organisms to outside stimulation and pathophysiological changes, as well as multiple dynamic response of the level of in vivo metabolites caused by genetic mutation. It is extensively used in basic research of system biology, materia medica, clinical medicine, etc. In the forensic field, metabolomics mainly focuses on forensic toxicology, but with the generalization of certain techniques, it's foreseeable that metabolomics has a broad research prospect in forensic pathology. This article summarizes the major analysis techniques and methods of metabolomics, describes the research status of metabolomic techniques in the field of forensic pathology application research, including postmortem interval and death cause. Moreover, this article summarizes and discusses the potential applicable areas, in order to provide reference for relative research and application.

Rapid Determination of 13 Sedative Substances and Their Metabolites in Blood by LC-MS/MS / 法医学杂志

Objective To establish an analysis method for simultaneous determination of 13 sedative substances and their metabolites in blood by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry （LC-MS/MS） technology and to apply the method to actual cases. Methods The samples were extracted with ethyl acetate after an internal standard was added. The extract was condensed until it was nearly dry and then its residues were dissolved with methanol, filtered through 0.22 μm filter and finally determined. The 13 sedative substances and their metabolites were separated through the C18 chromatographic column, then gradient elution was performed on them with methanol and 20 mmol/L ammonium formate （containing 0.1% formic acid） solution. After that, they were determined in the electrospray positive ion mode and quantified by internal standard method. Results The 13 sedative substances and their metabolites in blood showed good linearity in the range of 5-200 μg/L with correlation coefficients ranging from 0.990 3 to 0.999 8. The detection limits were 0.1-1.0 μg/L. Recovery rates of sedative substances were in the range of 71.2%-93.4% when solutions with concentrations of 10, 50 and 200 μg/L were added. The deviations of intra-day and inter-day relative standard deviations （RSD） were not more than 8.6%. Accuracies （bias） were within ±9.8%. Conclusion This method is rapid, simple, effective and sensitive, and can be applied to analysis of 13 sedative substances and their metabolites in blood in forensic toxicology.

Trial of Chloroquines in the Treatment of COVID-19 and Its Research Progress in Forensic Toxicology / 法医学杂志

Chloroquines are the long-established prescription drug, which are often used clinically to treat malaria and connective tissue diseases. Since December 2019, corona virus disease 2019 （COVID-19） outbreaks caused by 2019 novel coronavirus （2019-nCoV） has occurred in China and many countries around the world. Due to the lack of drugs against COVID-19, the disease spreads rapidly and the mortality rate is relatively high. Therefore, specific drugs against 2019-nCoV need to be quickly screened. The antimalarial drug chloroquine phosphate which has already been approved is confirmed to have an anti-2019-nCoV effect and has been included in diagnostic and therapeutic guidelines. However, awareness of the risk of chloroquine phosphate causing acute poisoning or even death should be strengthened. The current dosage recommended in clinical treatment is larger than that in previous treatment of malaria and the period of treatment is longer. Many provinces have required close clinical monitoring of adverse reactions. This paper reviews the pharmacological effects, poisoning and toxicological mechanisms, in vivo metabolism and distribution, and forensic issues of chloroquine drugs, in order to provide help to forensic practice and clinical work.

Mortalidade por suicídio no Rio Grande do Sul: uma análise transversal dos casos de 2017 e 2018 / Mortalidad por suicidio en Rio Grande do Sul, Brasil: un análisis transversal de casos en 2017 y 2018 / Suicide mortality in Rio Grande do Sul, Brazil: a cross-sectional analysis of cases, 2017-2018

Resumo Objetivo: Analisar o perfil epidemiológico e toxicológico dos casos de suicídio no Rio Grande do Sul, Brasil, em 2017 e 2018. Métodos: estudo transversal com dados das ocorrências policiais e laudos do Instituto-Geral de Perícias do estado; foram realizadas análises de correspondência múltipla e construídos modelos de regressão logística. Resultados: registraram-se 2.564 suicídios (11,3/100 mil habitantes/ano), majoritariamente do sexo masculino (79,4%) e na faixa etária de 50 a 54 anos (10,3%); o principal meio utilizado foi o enforcamento (72,5%); em 29,1% dos casos, houve resultado positivo para etanol, e, em 36,1%, para outros psicotrópicos; os jovens apresentaram 4,5 vezes (IC95% 2,7;7,7) e 2,4 vezes (IC95% 1,5;3,6) maior chance de serem vítimas quando havia resultados positivos para alguma substância ilícita ou ausência parental, respectivamente. Conclusão: predominaram vítimas do sexo masculino e adultas, o enforcamento foi o meio mais comum e, em um terço dos casos, havia presença de psicotrópicos.

Resumen Objetivo: analizar el perfil epidemiológico y toxicológico de los casos de suicidio en Rio Grande do Sul, Brasil, en 2017 y 2018. Métodos: estudio transversal con datos de informes policiales y del Instituto General Forense; se realizaron múltiples análisis de correspondencia y se construyeron modelos de regresión logística. Resultados: hubo 2.564 suicidios (11,3/100 mil habitantes/año), mayoritariamente de hombres (79,4%) y en el grupo de 50 a 54 años de edad (10.3%); el método principal fue ahorcamiento (72.5%); en el 29.1% de los casos hubo un resultado positivo para el etanol y en el 36.1% para otras drogas psicotrópicas; los jóvenes tenían 4.5 veces (IC95% 2.7;7,7) y 2.4 veces (IC95% 1.5;3,6) más probabilidades de ser las víctimas cuando había resultados positivos para alguna sustancia ilegal o ausencia parental, respectivamente. Conclusión: predominaban las víctimas masculinas y adultas, el ahorcamiento era el medio más común y, en un tercio de los casos había drogas psicotrópicas.

Abstract Objective: to analyze the epidemiological and toxicological profile of suicide cases in Rio Grande do Sul, Brazil, in 2017 and 2018. Methods: this was a cross-sectional study with data from police incident reports and state General Forensic Institute records; multiple correspondence analyses were performed and logistic regression models were built. Results: there were 2,564 suicides (11.3/100,000 inhabitants/year), mostly involving males (79.4%), and the 50-54 years age group (10.3%); the main method was hanging (72.5%); positive results for ethanol were found in 29.1% of cases and for other psychotropic drugs in 36.1% of cases; young people were 4.5 times (95%CI 2.7;7.7) and 2.4 times (95%CI 1.5;3.6) more likely to be the victims when there were positive results for an illegal substance or parental absence, respectively. Conclusion: male and adult victims predominated, hanging was the most common means, and, in one third of the cases, psychotropic drugs were present.

Bibliometrics Analysis of Forensic Toxicology Literature of Mainland Chinese Scholars in SCIE Journals / 法医学杂志

Objective To conduct bibliometrics analysis of forensic toxicology literature of mainland Chinese scholars published in SCIE journals between 1998 and 2018. Methods Gephi 0.9.2 software was used for bibliometrics analysis. The status of forensic toxicology research in mainland China was network visualized through data analysis of institutional cooperation, author collaboration, fund support, keywords co-occurrence as well as literature interpretation. Results The total number of papers published in SCIE journals in the past twenty years by mainland Chinese scholars was 242, and increased year by year. Thematic studies, such as analysis and evaluation of toxins in hair, identification of new psychoactive substances, optical enantiomer analysis of amphetamines, analysis of toxic animal and plant components, etc, reached the international advanced level. Conclusion The forensic toxicology discipline in our country has developed rapidly in recent years. The opening and development of forensic science in colleges and universities, the constant emerging of new research teams, especially the funding of major special projects of National Natural Science Foundation of China and the Ministry of Science and Technology, have promoted high level research output and academic status of Chinese forensic toxicology on the international stage.

Identification of Tiletamine, Zolazepam and Their Metabolites in Drug Facilitated Sexual Assault by GC-QTOF-MS / 法医学杂志

Objective To identify tiletamine, zolazepam and their metabolites in samples from drug facilitated sexual assault by gas chromatography-quadrupole time of flight mass spectrometry （GC-QTOF-MS）. Methods Urine samples of victims were collected, and detected by GC-QTOF-MS after liquid-liquid extraction and concentration. The molecular formula of fragments ions was identified by determination of accurate mass numbers, to detect related substances. Results Tiletamine, zolazepam, three metabolites of tiletamine and two metabolites of zolazepam were identified in urine samples from actual cases. Conclusion GC-QTOF-MS provides abundant and accurate information of fragment ions mass numbers, which can be used for qualitative identification of tiletamine, zolazepam and their metabolites in drug facilitated sexual assault.

Establishment and Its Application of UPLC-MS/MS Method for 20 Fentanyl-related Substances in Blood / 法医学杂志

Objective To establish an ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） rapid determination method for simultaneous analysis of 20 fentanyl-related substances in blood. Methods With fentanyl-D5 as an internal standard, the blood was extracted by liquid-liquid extraction （LLE）, then separated with an ACQUITY UPLC HSS T3 chromatographic column, and finally 20 fentanyl-related substances were simultaneously analyzed with multiple reaction monitoring （MRM） mode. Results The limits of detection （LOD） of all compounds were 0.02-0.03 ng/mL, and the limits of quantitation （LOQ） were 0.05-0.2 ng/mL. Within the mass concentration range of 0.05-40 ng/mL, 20 fentanyl-related substances had a good linear relationship, and correlation coefficients were larger than 0.99. The accuracy of the method was 87.69%-114.68% and the extraction recovery rate was 85.35%-101.80%, and no significant matrix effect was observed. The established method was successfully applied to the detection of sufentanil in rat blood after sufentanil was injected. Sufentanil could still be detected in blood of rats 10 h after sufentanil injection. Conclusion The established method has the advantages of simple pretreatment, high sensitivity and good selectivity, and can be used for the determination of fentanyl-related substances in forensic toxicology analysis.

Application of Dispersive Liquid-Liquid Microextraction in Forensic Toxicological Analysis / 法医学杂志

Currently, the main sample pretreatment methods for forensic toxic analysis are liquid-liquid extraction （LLE） and solid-phase extraction （SPE）. As a simple, convenient, and low-cost LLE method, dispersion liquid-liquid microextraction （DLLME） has high enrichment factor and good extraction efficiency, and therefore has attracted the attention of many researchers in the field of toxicology analysis in recent years. As a multi-functional microextraction method, DLLME has been widely used in the analysis of pesticides, sleeping sedatives, drugs and heavy metal poisons in forensic toxic analysis. Meanwhile, it can also be used in combination with such a variety of analytical instruments as gas chromatography-electron capture detectors （GC-ECD）, high performance liquid chromatography-diode array detectors （HPLC-DAD）. As a sample pretreatment method, DLLME has the advantages of simple operation, less use of organic solvent, reliable results and good reproducibility, thus can meet the requirements of modern court toxic analysis.

Research Progress on Detection Methods of Amphetamines in Human Hair / 法医学杂志

Amphetamines are chemical synthetic drugs that are becoming increasingly popular in China. As a common sample in the inspection of poisons, hair has the advantages of easy storage, good stability, and long detection time compared with traditional human body fluid samples （blood, urine）, thus possesses an unique application value in the field of forensic toxicology analysis. By now, methods for detecting amphetamines in human hair have been widely used, and validity of the results has been recognized and adopted by the court. This paper reviews domestic and foreign research progress of the detection of amphetamines in hair samples, including the pretreatment and analytic methods.

Avaliação da presença de cocaína e anfetamina em amostras de sangue post mortem e de indivíduos vivos, utilizando técnica de microextração em fase líquida (HF-LPME) / Amphetamine, cocaine and tetrahydrocannabinol evaluation in blood samples of living people and post mortem blood samples using microextraction technique in liquid phase (HF-LPME)

Estima-se atualmente que mais de 5% da população mundial vem fazendo uso recreativo de algum tipo de substância psicoativa, sendo que o direito a esse uso é tema recorrente da sociedade contemporânea. Por apresentar riscos associados à saúde e a segurança das populações, o uso abusivo dessas substâncias tem instigado a toxicologia social na busca de respostas, com as quais se possa caracterizar, analisar e gerenciar esses riscos. Drogas de grande consumo no Brasil são a anfetamina, cocaína e Cannabis sativa. Esta tese desenvolveu uma nova metodologia para detectar e quantificar anfetamina, cocaína e tetrahidrocanabinol em sangue total, com uso de microextração em fase líquida via fibra de polipropileno (HF-LPME), seguida de cromatografia gasosa acoplada a espectrometria de massa (GC-MS). Trata-se de uma técnica que apresenta vantagens sobre as tradicionais, uma vez que demanda quantidades menores de solvente orgânico, diminuindo riscos e custos de processo. Também propôs um estudo com a aplicação dos métodos em 69 amostras de sangue de vivos e de post mortem, as quais foram obtidas por convênio com a superintendência da polícia técnica científica de São Paulo (SPTC/SP). Os métodos desenvolvidos foram validados de acordo com diretrizes internacionais de interesse forense. Como resultado da validação, os métodos desenvolvidos se mostraram precisos e exatos para anfetamina e cocaína. O limite de detecção da cocaína foi de 5 ng . mL-1 e o limite de quantificação de 10 ng . mL-1. Quanto a anfetamina, os limites de detecção e de quantificação foram de 5 ng . mL-1. A técnica de HF-LPME não foi aplicável ao tetraidrocanabinol (Δ9-THC). Como resultado da análise das amostras, 40% delas apresentaram resultados positivos para cocaína. Desses positivos, 35% foram oriundos das matrizes de sangue de vivos e 64% oriundos de sangue post mortem. Nenhuma delas apresentou resultado quantificável para anfetamina

It is currently estimated that more than 5% of the world's population has been doing recreational use of some kind of psychoactive substances and the legal right to such use is a recurring theme debated by contemporary society. Due to the risks associated with populations health and safety, the abusive use of these substances has been instigating by social toxicology to search for answers to characterize, analyze and manage these risks. Drugs of great consumption in Brazil are, amphetamine cocaine and marijuana. This thesis proposes to develop a new methodology to detect and quantify psychoactive drugs in whole blood with the use of liquid phase microextraction by polypropylene fiber (HFLPME), followed by gas chromatography coupled to mass spectrometry (GC-MS). It is a technique that presents advantages compared with traditional ones, because of the smaller amounts demands of organic solvent, reducing risks and process costs. It also proposes a study with 69 blood samples taken from living persons and post mortem blood samples, which were obtained by agreement with the Superintendency of São Paulo Scientific Technical Police (SPTC / SP). The methods developed were validated according to international guidelines of forensic interest. As a result of the validation, the methods developed were precise and accurate for amphetamine and cocaine. The limit of cocaine detection was 5 ng . mL-1 and the limit of quantification was 10 ng . mL-1. As for amphetamine, the limits of detection and quantification were 5 ng . mL-1. The HF-LPME technique was not applicable to tetrahydrocannabinol (Δ9-THC). As a result of the sample analysis, 40% of them presented positive results for cocaine. Of these, 35% were from blood samples taken from living persons and 64% from the post mortem blood samples. None of the samples presented quantifiable results for amphetamine

Determinação de club dugs em sangue total por cromatografia líquida acoplada a espectrometria de massas com analisador hí­brido quadrupolo-tempo de voo (LC-QTOF-MS) / Determination of club drugs in whole blood by liquid chromatography coupled with mass spectrometry with hybrid quadrupole time-of-flight mass analyzer (LC-QTOF)

As chamadas club drugs compreendem um vasto grupo de substâncias frequentemente utilizadas em bares, festas e raves, com a finalidade de intensificar o contato social e a estimulação sensorial. Englobam desde substâncias sintéticas comumente conhecidas, como a anfetamina, a metanfetamina, o MDMA, até moléculas de surgimento mais recente, denominadas novas substâncias psicoativas. Isoladas ou associadas a outras drogas, é possível que sejam causa de morte per se, ou que predisponham o usuário a envolver-se em situações potencialmente fatais, sendo necessário que os órgãos de Perícia Criminal (Institutos Médico Legais e Institutos de Criminalística) estejam aptos a detectar e quantificar essas substâncias em amostras biológicas. O presente trabalho teve como objetivo desenvolver um método analítico para identificação e quantificação de club drugs em sangue total, utilizando cromatografia líquida acoplada a espectrometria de massas com analisador híbrido quadrupolotempo de voo (LC-QTOF). Após o desenvolvimento do método, este foi validado utilizando as diretrizes do guia de validação do Scientific Working Group for Forensic Toxicology (SWGTOX), sendo analisados de linearidade, limite de detecção, limite de quantificação, efeito matriz, precisão intradia, precisão interdia, exatidão e integridade de diluição, além de recuperação e eficiência do processo. O método desenvolvido compreendeu a determinação de MDA, MDMA, 2C-B, DOB, cetamina, mCPP, cocaína e cocaetileno. Amostras provenientes de casos reais de morte não natural, oriundas do Instituto Médico Legal Aristoclides Teixeira de Goiânia - GO foram analisadas pelo método desenvolvido. 56 casos foram selecionados, em sua maioria com histórico de morte por projétil de arma de fogo e acidente de transito. Das 56 amostras analisadas, 28,5% (n=16) foram positivas para cocaína e/ou cocaetileno. As demais substâncias pesquisadas não foram encontradas nas amostras

Club drugs are a large group of substances consumed in pubs, parties and raves, aiming to intensify social contact and sensorial stimulation. The term comprises largely known substances such as amphetamine, methamphetamine, 3,4-methylenodioxymethamphetamine (MDMA), as well as so-called new psychoactive substances, which are synthetic drugs recently developed or recently introduced in drug market. Club drugs can be taken alone, combined with each other or, most frequently, with alcohol or other commonly abused drugs such as cocaine. In any of these situations, club drugs can possibly be the cause of death or potentialize the involvement of the user with crime and potentially fatal behavior. Thus, official organisms in charge of criminal investigation must be capable of identifying and quantifying these substances in biological samples. The present work aimed the development of an analytical method to identify and quantify club drugs in whole blood, using liquid chromatography - mass spectrometry with hybrid analyzer quadrupole - time of flight (LC-QTOF). After analytical development, the method was validated according to do Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines, evaluating linearity, limit of detection, limit of quantification, matrix effect, precision, intermediate precision, bias and dilution integrity, besides recovery and process efficiency. The developed method comprised MDA, MDMA, 2C-B, DOB, ketamine, mCPP, cocaine and cocaethylene determination. Real samples related to non-natural deaths were collected at Institute of the Legal Medicine Aristoclides Teixeira, Goiânia, Goiás, Brazil, and analyzed by the developed method. 56 cases were selected, most of them related to fire gun injury and traffic events, 28,5% (n=16) of them being positive for cocaine and/or cocaethylene. None of the other drugs comprised in the analysis were detected in these samples

Uso da microextração por sorbente empacotado (MEPS) para preparo de amostras em análises toxicológicas envolvendo fármacos benzodiazepí­nico / Microextraction by packed sorbent (MEPS) for sample preparation in toxicological analyses involving benzodiazepines

A microextração por sorbente empacotado (MEPS) é uma técnica de preparo de amostras ainda pouco utilizada no âmbito da toxicologia, em que os mesmos princípios da extração em fase sólida convencional são adaptados para uma escala miniaturizada. As principais vantagens da técnica estão associadas ao pequeno volume de amostra e de solventes utilizados, à possibilidade de realizar múltiplas extrações com um mesmo cartucho e à facilidade de automação. Os benzodiazepínicos possuem grande relevância na toxicologia dada sua ampla utilização e seus efeitos que podem, por exemplo, comprometer a capacidade de dirigir, além do uso abusivo, e como drogas facilitadoras de crimes. Neste trabalho, um método de MEPS foi desenvolvido e otimizado para a determinação de sete benzodiazepínicos e seus produtos de biotransformação (diazepam, clonazepam, flunitrazepam, alprazolam, bromazepam, 7-aminoflunitrazepam e nordiazepam) utilizando 100 µL de amostra de sangue total post mortem. Após a extração, os eluatos foram analisados por cromatografia líquida em fase reversa acoplada a espectrometria de massas. O método foi validado de acordo com as recomendações do Scientific Working Group for Forensic Toxicology, apresentando linearidade adequada de 5 a 500 ng.mL-1 . Os valores de exatidão (90,4 a 109,5%), precisão intra-dia (2,5 a 10,7 %CV) e inter-dia (1,1 a 8,0 %CV) também foram satisfatórios. MEPS foi realizada mais de 60 vezes com a mesma fase extratora sem evidências de contaminação cruzada. Dez amostras reais fornecidas pelo Instituto Médico Legal de São Paulo foram analisadas. Foram quantificados diazepam, nordiazepam, clonazepam e bromazepam. Os resultados encontrados em cada uma das amostras foram comparados com dados da literatura

Microextraction by packed sorbent (MEPS) is a sample preparation technique still little used in toxicology, where the same principles of conventional solid phase extraction are adapted to a miniaturized scale. The main advantages of the technique are associated with the small volume of sample and solvents required, the possibility of performing multiple extractions with the same cartridge and ease process automation. Benzodiazepine drugs are relevant in toxicology because of their widespread use, and effects (which may, for example, compromise the ability to drive vehicles), abuse and records as crime-facilitating drugs. In this work, a MEPS method was developed and optimized for a determination of seven benzodiazepines and their metabolites (diazepam, nordiazepam, clonazepam, flunitrazepam, 7-aminoflunitrazepam, alprazolam, and bromazepam) using 100 µL of post mortem whole blood. After extraction, the eluates were analyzed by reversed-phase liquid chromatography coupled to mass spectrometry. The method was validated according to the recommendations of the Scientific Working Group for Forensic Toxicology, presenting adequate linearity from 5 to 500 ng.mL-1 . The values of accuracy (90.4 to 109.5%), intra-day precision (2.5 to 10.7 %CV) and inter-day (1.1 to 8.0 %CV) also presented satisfactory results. MEPS was performed more than 60 times with the same extractive phase without compromising the results with the evidence of carryover. Institute of Legal Medicine were submitted to analysis by MEPS-LC-MS/MS. In these samples, the following analytes were quantified: diazepam, nordiazepam, clonazepam and bromazepam. The results found in each of the samples were compared with data from the literature

Estudo da estabilidade de novas substâncias psicoativas (NPS) em amostras de sangue seco em papel (DBS), e sua aplicação em toxicologia forense / Stability of new psychoactive substances (NPS) in dried blood spots (DBS), and its application in forensic toxicology

Resumo: Introdução: A classe de drogas de abuso conhecida como novas substâncias psicoativas ou, ainda, drogas desenhadas (do inglês new psychoactive substances (NPS) ou designer drugs) é composta por substâncias químicas obtidas a partir de alterações estruturais de substâncias ou mistura de substâncias psicoativas já existentes (e ilícitas), a fim de mimetizar e/ou potencializar os efeitos proporcionados por estas, com a vantagem de circundar a legislação antidrogas vigente. Dentro da classe das NPS, os grupos de maior destaque atualmente são das catinonas sintéticas, dos canabinóides sintéticos e dos NBOMes (feniletilaminas N-2-metoxibenzil substituídas). As catinonas sintéticas, vendidas pela internet como "sais de banho" ou bath salts, são substâncias estruturalmente relacionadas a catinona, um alcalóide presente no Catha edulis (Khat), com propriedades estimulantes. A classe dos NBOMes é derivada da classe dos alucinógenos 2C, a partir da adição de um grupo N-2-metoxibenzil na amina primária. Os NBOMes possuem ação agonista nos receptores de serotonina, especialmente do subtipo 5-HT2A, o que confere os efeitos alucinógenos. Objetivos: Desenvolver e validar métodos para identificação e quantificação de algumas das NPS de maior relevância em amostras de manchas de sangue seco em papel (do inglês dried blood spots, DBS) e comparar a estabilidade entre dois tipos de amostras (DBS e sangue total), em três diferentes temperaturas (ambiente, 4 °C e -20 °C) e períodos de armazenamento. Metodologia: As amostras de DBS e sangue total foram analisadas em cromatógrafo líquido acoplado à espectrômetro de massas com analisador de massas triplo quadrupolar (LC-MS/MS), utilizando os métodos primeiramente desenvolvidos e validados para cada classe de NPS (catinonas sintéticas e NBOMes). Resultados: A técnica de DBS apresentou um aumento significativo da estabilidade das NPS em comparação à técnica convencional de armazenamento de sangue total. Para os NBOMes, observou-se que os compostos eram estáveis no DBS por período de tempo de até 6 meses, nas três temperaturas estudadas, enquanto que no sangue total, os analitos tiveram uma queda maior que 20% da concentração em 15 ou 30 dias em temperatura ambiente e 180 dias para 4 °C. Para as catinonas, em temperatura ambiente, observou-se baixa estabilidade nas duas matrizes. Porém, para armazenamento à 4 °C, observou-se uma queda na concentração inicial maior que 20% com 60 e 90 dias para mefedrona e benzedrona em DBS, respetivamente, contra 45 e 25 dias. Catinonas que possuem grupamento metilenodioxi em sua estrutura, como a butilona e a pentilona, foram mais estáveis, independente da matriz, em comparação àquelas com grupamento alquila no anel aromático, como mefedrona e benzedrona. Conclusão: A técnica de DBS se mostrou vantajosa para análises forenses em comparação à técnica convencional de armazenamento de sangue total. Além de facilitar o armazenamento (por ocupar menos espaço), sua extração se torna mais rápida e facilitada, já que envolve menos etapas, além de tornar possível a identificação dos analitos de interesse por um maior período de tempo, podendo facilmente ser aplicada na rotina laboratorial(AU)

Abstract: Introduction: New psychoactive substances (NPS) or designer drugs is a class of drugs of abuse composed of chemical substances obtained from structural alterations of substances or mixture of existing psychoactive substances (and illicit), in order to mimic and/or maximize their effects, with the advantage of circumventing existing anti-drug legislation. Within the NPS class, the most prominent groups currently are synthetic cathinones, synthetic cannabinoids and NBOMes (phenylethylamines N-2-methoxybenzyl substituted). Synthetic cathinones, sold by the internet as "bath salts", are substances structurally related to cathinone, an alkaloid present in Catha edulis (Khat), with stimulant properties. The class of NBOMes is derived from the hallucinogen class 2C, from the addition of an N-2-methoxybenzyl group to the primary amine. NBOMes have agonist action at serotonin receptors, especially the 5-HT2A subtype, which confers the hallucinogenic effects. Objectives: To develop and validate methods to identify and quantify some of the most relevant NPS in dried blood spots (DBS) samples and to compare the stability between two matrixes (DBS and whole blood), at three different temperatures (ambient, 4 °C and -20 °C) and storage periods. Method: DBS and whole blood samples were analyzed using a liquid chromatography tandem mass spectrometer with a triple quadrupole analyzer (LC-MS/MS), using the developed and validated methods for each class of NPS (synthetic cathinones and NBOMes). Results: The DBS technique showed a significant increase in the NPS stability compared to the conventional whole blood storage technique. For the NBOMes, the compounds were found to be stable in DBS for a time period of up to 6 months, at the three temperatures studied, whereas in whole blood, the analytes had a decreased higher than 20% of the initial concentration in 15 or 30 days at room temperature and 180 days at 4 °C. For the cathinones, at room temperature, low stability was observed in both matrixes. However, for storage at 4 °C, the initial concentration decreased more than 20% at 60 and 90 days for mephedrone and benzedrone in DBS, respectively, against 45 and 25 days. Cathinones having methylenedioxy group in their structure, such as butylone and pentylone, were more stable, independent of the matrix, compared to those with alkyl group on the aromatic ring, such as mephedrone and benzedrone. Conclusion: The DBS technique proved to be advantageous for forensic analysis compared to the conventional storage technique. In addition to occupying less storage space, DBS extraction becomes faster and easier, since it involves fewer steps, besides to make possible to identify the analytes of interest for a longer period of time, which can easily be applied in the laboratory routine(AU)

Confirming Indicators of Qualitative Results by Chromatography-mass Spectrometry in Biological Samples / 法医学杂志

Because of the exist of complex matrix, the confirming indicators of qualitative results for toxic substances in biological samples by chromatography-mass spectrometry are different from that in non-biological samples. Even in biological samples, the confirming indicators are different in various application areas. This paper reviews the similarities and differences of confirming indicators for the analyte in biological samples by chromatography-mass spectrometry in the field of forensic toxicological analysis and other application areas. These confirming indicators include retention time （RT）, relative retention time （RRT）, signal to noise （S/N）, characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc.

Simultaneous Quantitative Analysis of Koumine, Gelsemine and Gelsenicine in Biological Samples by LC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a LC-MS/MS method which is accurate and sensitive for determination of koumine, gelsemine, and gelsenicine in biological samples and to verify the method.@*METHODS@#Strychnine was used as internal standard. Analytes in blood, urine and liver with 1% sodium hydroxide solution were extracted by ethyl acetate. Chromatographic separation was achieved on a ZORBAX SB-C₁₈ column （150 mm×2.1 mm, 5 μm）, and gradient elution was performed with the buffer solution of methanol-20 mmol/L ammonium acetate （including 0.1% formic acid and 5% acetonitrile） as mobile phase. Qualitative and quantitative analysis was performed in the multiple reaction monitoring mode coupled with an electrospray ionization source under positive ion mode（ESI⁺）.@*RESULTS@#The linearity of koumine, gelsemine and gelsenicine in blood, urine and liver was good within corresponding linear limitation and the correlation coefficients （r）>0.995 0. The limits of detection were 0.1 ng/mL （0.1 ng/g）, 0.1 ng/mL （0.1 ng/g） and 0.01 ng/mL （0.01 ng/g）, respectively. The extraction recovery and accuracy of the alkaloids ranged from 61.9% to 114.6% and 92.4% to 114.3%, respectively. The relative standard deviations of the intra-day and inter-day precisions were not more than 11.0%.@*CONCLUSIONS@#The method is selective, sensitive and suitable for simultaneous determination of koumine, gelsemine and gelsenicine in body fluids and tissues, which offering technical support for clinical diagnosis and treatment and forensic toxicological analysis of Gelsemium elegans poisoning.

Advance of Forensic Research in Insulin Poisoning / 法医学杂志

Insulin as a common clinical hypoglycemic agent can effectively control serves to lower the concentration of blood glucose. However, insulin overdose can lead to death. In the whole fatal cases of insulin overdose, medical accident is the most common, followed by suicide. Though insulin homicide is extremely rare, it deserves great attention. Though there are some researches about insulin poisoning on forensic toxicology and pathology, it is still a difficult task in forensic practice. In this paper, the mechanism of death, pathological changes, detection methods and diagnose criteria of insulin overdose will be discussed in the view of forensic toxicology and pathology. We hope that this paper could enhance relative knowledges of insulin poisoning for medical examiners.