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.

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.

Ecotoxicological evaluation of sediments applied to environmental forensic investigation / Avaliação ecotoxicológica de sedimentos aplicada à perícia criminal ambiental

Abstract The present study aimed to evaluate the potential for using toxicity assays with sediment samples for the detection of water pollution caused by the discharge of tannery effluents into water bodies and its application to environmental forensic investigation. The study included ecotoxicological evaluation of sediments, survey of benthic organisms in the field, as well as chromium, cadmium and lead dosage which provided data for a sediment quality triad evaluation. The sediment samples showed acute and chronic toxicity to the bioindicators, low biodiversity of benthic macrofauna and high chromium concentration, reaching up to 4365 mg.Kg–1. A close relationship was observed between the separate results of ecotoxicological sediment evaluation and the sediment quality triad. The sediment ecotoxicological assessment proved to be applicable to tracking sources of contamination related to tanneries and similar activities in environmental forensics.

Resumo O objetivo do presente estudo foi avaliar o potencial de aplicação de ensaios de toxicidade com amostras de sedimento para constatação de poluição aquática causada por lançamentos de efluentes de curtumes em cursos d’água e seu emprego na perícia criminal ambiental. O estudo incluiu avaliação ecotoxicológica de sedimentos, avaliação da fauna bentônica local e dosagem de cromo, cádmio e chumbo que forneceram dados para avaliação da tríade de qualidade dos sedimentos. As amostras de sedimentos mostraram efeito de toxicidade aguda e crônica aos bioindicadores, baixa biodiversidade da macrofauna bentônica e altas concentrações de cromo que chegaram a 4365 mg.Kg–1. Houve uma estreita relação entre os resultados isolados da avaliação ecotoxicológica e a tríade de qualidade de sedimentos. A avaliação ecotoxicológica demonstrou ser aplicável na identificação de fontes de contaminação relacionadas a curtumes e atividades similares em perícias ambientais.

Development and Application of Metabonomics in Forensic Toxicology / 法医学杂志

Metabonomics is an important branch of system biology following the development of genomics, transcriptomics and proteomics. It can perform high-throughput detection and data processing with multiple parameters, potentially enabling the identification and quantification of all small metabolites in a biological system. It can be used to provide comprehensive information on the toxicity effects, toxicological mechanisms and biomarkers, sensitively finding the unusual metabolic changes caused by poison. This article mainly reviews application of metabonomics in toxicological studies of abused drugs, pesticides, poisonous plants and poisonous animals, and also illustrates the new direction of forensic toxicology research.

Method development and validation for determining 1,3-butadiene in human blood by gas chromatography-mass spectrometry and head-space gas chromatography / 法医学杂志

To develop a simple, validated method for identifying and quantifying 1,3-butadiene (BD) in human blood by gas chromatography-mass spectrometry (GC-MS) and head-space gas chromatography (HS-GC). BD was identified by GC-MS and HS-GC, and quantified by HS-GC. The method showed that BD had a good linearity from 50 to 500 microg/mL (r > 0.99). The limits of detection and quantification were 10 microg/mL and 50 microg/mL, respectively. Both the intra-day precision and inter-day precision were < 6.08%, and the accuracy was 96.98%-103.81%. The method was applied to an actual case, and the concentration of BD in the case was 242 microg/mL in human blood. This simple method is found to be useful for the routine forensic analysis of acute exposure to BD.

Distribution of deltamethrin in acute poisoned rats / 法医学杂志

OBJECTIVE@#To establish an animal model in acute poisoned rat by deltamethrin and an analysis method for determination of deltamethrin by gas chromatography-electron capture detector (GC-ECD) and to study the distribution of deltamethrin in rats in order to provide the references for forensic medicine identification about such cases.@*METHODS@#Rats were administered with deltamethrin of different doses(512 and 1,024 mg/kg) and killed 1.5 h later to be dissected rapidly for tissues (blood, hearts, livers, lungs, kidneys and brains etc.). Samples were dehydrated by anhydrous sodium sulfate and extracted with petroleum ether and acetone (V:V=4:1). The level of deltamethrin was determined by GC-ECD.@*RESULTS@#There was a good separate between deltamethrin and endogenous impurities. The limit of quantification for deltamethrin in blood and liver were 0.1 microg/mL and 0.1 microg/g (S/N> or =10), respectively. The recovery rate of deltamethrin in blood was 91.55%-134.37% and both inter-day and intra-day precisions were less than 5.67%. The distribution of deltamethrin in poisoned rats with 512 mg/kg was as follow: lungs > livers > hearts > kidneys > blood > brains and with 1 024 mg/kg dose was lungs > blood > hearts > kidneys > brains > livers (P<0.05).@*CONCLUSION@#The GC-ECD method is sensitive for determination of deltamethrin. The distribution of deltamethrin in rats has a dose-dependent manner. The study suggests that samples of blood, hearts, livers, lungs, kidneys and brains are suitable for deltamethrin poisoned analysis.

Toxicology unit in department of forensic medicine emphasis from a study from North East India.

In suspected poisoning cases the final opinion as to the cause of death is generally kept pending till receipt of the chemical analysis report from the Forensic Science Laboratory (FSL). Cases of suspected poisoning deaths from Kamrup district coming to the GMCH morgue were studied from 1st August 2008 to 31st August 2009 with aim of analyzing the time consumed at various levels. A total of 2592 autopsies were performed during study period and in 160 cases viscera were preserved. Viscera Report of 60 is awaited as on 1st November 2009. 31 cases gave positive results for poison and 69 cases gave negative report. In 21.9% of cases police took more than a month to take the samples to SFSL and in more than 47.5% cases SFSL took >2 months to convey report. In nearly all cases the final opinion as to the cause of death was given the same day on which the report was received. So, establishment of Toxicological Laboratories in Dept of Forensic Medicine and Toxicology can minimize this delay.

Redistribuição postmortem de barbitúricos em tecidos biológicos humanos / Postmortem redistribution of barbiturates in human biological tissues

Os barbitúricos são fármacos com atividade depressora do sistema nervoso central e estão relacionados com elevados números de casos de intoxicações e uso não-médico em vários países. No Brasil, a droga antiepiléptica mais encontrada em casos de intoxicação é o fenobarbital, pois os pacientes relatam que "essa é uma substância com ação forte no cérebro". De fato, os barbitúricos estão altamente relacionados com tentativa de suicídio e homicídio. Nesses casos existe a necessidade da quantificação dessas substâncias para correlacionar com a causa mortis. No entanto, as análises toxicológicas postmortem são de difícil execução e interpretação, pois a concentração de agentes tóxicos encontrados é bastante complexa e afetada não só pela condição de deterioração do corpo, mas também por um processo conhecido como redistribuição postmortem. Em geral, concentrações mais elevadas são encontradas no sangue situado nos sítios centrais (como o sangue coletado da cavidade cardíaca) em comparação aos níveis verificados nos vasos periféricos (como a veia femoral). Em outros casos, o tempo entre a morte e o exame postmortem é suficiente para que algumas substâncias que normalmente estariam presentes no sangue não estejam mais disponíveis neste fluido biológico. Há ainda um agravante, pois não existem valores de referências para a maioria das amostras biológicas não-convencionais, dificultando assim a interpretação dos resultados. Os exames toxicológicos devem ser realizados em amostras biológicas e tem como objetivo a avaliação da intoxicação como circunstância qualificadora do delito, como causa de periculosidade ou imputabilidade. O objetivo deste trabalho foi o desenvolvimento e aplicação de métodos de identificação de barbitúricos (butalbital, secobarbital, pentobarbital e fenobarbital) em amostras postmortem (sangue cardíaco, sangue femoral e fígado). Os analitos foram extraídos das amostras utilizando a micro extração em fase líquida (LPME), identificados...

Barbiturates are a class of drugs that act as central nervous system depressant and are associated with high numbers of poisoning cases and non-medical use in several countries. In Brazil, phenobarbital is the most related antiepileptic drug involved in intoxication cases. Patients report that "this drug is a substance with strong action in the brain." In fact, barbiturates are highly related to attempted suicide and homicide cases, in which quantification of these substances to correlate with the possible cause of death is necessary. However, postmortem toxicological analyses are difficult to perform and interpret, because the concentration of toxic agents found is quite complex and affected not only by deterioration condition of the body but also by a process known as postmortem redistribution. In general, higher concentrations are found in the blood located in central sites (e.g. heart cavity) compared with the levels found in peripheral vessels (such as the femoral vein). In other cases, the time between death and postmortem examination is enough for some substances that would normally be present in the blood are no longer available in this biological fluid. Besides, there are few reference values for most non-conventional biological samples, making it difficult to interpret the results. The objective of this work was the development and application of methods for identification of barbiturates (butalbital, secobarbital, pentobarbital and phenobarbital) in postmortem samples (heart blood, femoral blood and liver). The analytes were extracted by using liquid-phase micro extraction (LPME) and quantified by gas chromatography-mass spectrometry (GC-MS). After the development and validation, analytical methods were applied in real cases of eleven corpses autopsied by Death Verification Service of São Paulo City (USP-SVO), with suspected of barbiturates involvement. Nine cases were positive for phenobarbital. The mean ratio of blood femoral / cardiac blood was...

Comparison of morphine and codeine concentration in urines of heroin abusers and codeine users / 法医学杂志

OBJECTIVE@#To compare morphine and codeine concentration in urines of heroin abusers and codeine users and to discuss the judgment index to distinguish between heroin abuser and codeine user.@*METHODS@#The urines of heroin abusers and codeine users were collected at different time periods. After protein precipitation, the urine samples were conducted for the qualitative and quantitative analysis of morphine and codeine by UPLC-MS/MS. And the results were all statistically analyzed.@*RESULTS@#Statistical analysis showed that morphine and codeine concentration in urines of heroin abusers and codeine users were both abnormal distributions. The probability of the heroin abuser would be more than 95% and less than 5% for the codeine user when the concentration of morphine in urine sample was more than 67 ng/mL. The probability of the codeine user would be more than 95% and less than 5% for the heroin abuser when the concentration of morphine in urine sample was less than 67 ng/mL.@*CONCLUSION@#The morphine concentration in urine could be used as a criterion to distinguish the heroin abuser from the codeine user, while the codeine concentration could not.

Measurement of acetonitrile in blood and urine by head-space gas chromatography / 法医学杂志

OBJECTIVE@#To establish the method for measurement of acetonitrile in blood and urine by head-space gas chromatography.@*METHODS@#DB-ALC1 (30 m x 320 microm x 1.8 microm) and DB-ALC2 (30 m x 320 microm x 1.2 microm) capillary column were used to measure the acetonitrile in blood and urine with the isopropanol as internal standard reference.@*RESULTS@#The limits of detection of acetonitrile in both blood and urine were 0.5 microg/mL, with a linear range of 5-1000 microg/mL (r = 0.999).The accuracy of this method was 93.2%-98.0%. The RSD for the intra-day and inter-day were less than 3.7%.@*CONCLUSION@#The method is capable for measurement analysis of acetonitrile in blood and urine.

Determination of propofol in human blood by GC-MS / 法医学杂志

OBJECTIVE@#To establish a gas chromatography-mass spectrometry (GC-MS) method for determination of propofol in human blood.@*METHODS@#Propofol and 2-(tert-Butyl)-4,6-dimethylphenol (internal standard) were isolated from human blood samples with liquid-liquid ether extraction. The organic layer was collected after centrifugation and dried using the water bath. The extracted residue was analyzed by GC-MS.@*RESULTS@#Propofol and the internal standard showed a good separation with a good linear concentration ranged from 0.02 to 10 microg/mL in blood. The linear function was y = 0.313 6 x-0.006 8 with the correlation coefficient of 0.9997. The precision of intra-day and inter-day were less than 4.8% and the lower limit of detection of propofol was 0.005 microg/mL. Propofol concentration of blood was 0.14 microg/mL using this method in the practice work.@*CONCLUSION@#The GC-MS method is rapid, sensitive, reliable and suitable for qualitative and quantitative analysis propofol of blood in forensic toxicological analysis and clinical drug monitoring.

Application of liquid chromatography-high resolution mass spectrometry in toxicological screening / 法医学杂志

Due to the diversity of toxicologically relevant substances, the uncertainty of target compounds and the specificity of samples, toxicological screening techniques have always been valued by the forensic toxicologists. Depending on its powerful separation ability, superhigh resolution and accurate mass measurement, combined with the two levels spectrum database matching and abundance ratio of isotope ion, the liquid chromatography-high resolution mass spectrometry (LC-HRMS) analyzers have increasingly advantage in screening and identification of chemical compound. This review focuses on the applications of LC-HRMS in screening and identification of drug-of-abuse, prescription drugs, pesticide and stimulant. The prospect of LC-HRMS in forensic toxicology analysis is also included.

Stability of estazolam in dog tissues preserved in formaldehyde solution / 法医学杂志

OBJECTIVE@#To investigate the stability of estazolam in biological samples preserved in formaldehyde solution.@*METHODS@#The dog was given intragastric administration of estazolam with a dose of 37.6 mg/kg and killed 2 h later. Heart, liver, kidney and brain of the dog were cut up into 1 g and preserved in 4% formaldehyde solution respectively. The content of estazolam in biological samples and formaldehyde solution were analyzed by HPLC at different times.@*RESULTS@#The content of estazolam in heart, liver, kidney and brain or in formaldehyde solution reduced gradually followed with the extention of preservation time. At the 63rd day, estazolam content in four tissues were 0.8%, 1.7%, 1.0% and 2.2% of the original content respectively.@*CONCLUSION@#Estazolam in tissues can diffuse into formaldehyde solution and decomposed quickly, so biological samples contained estazolam should not be preserved in formaldehyde solution.

Entomotoxicology: A review.

Entomotoxicology is the analysis of toxins in arthropods (mainly flies and beetles) that feed on carrion. Careful analyses of the community of insects encountered on a decomposing body, combined with knowledge of insect biology, ecology, and local environmental conditions can often provide valuable forensic insights. These can include the estimation of time since death, movement of the remains after death, indication of ante mortem injuries, and the presence of drugs or toxins. The accuracy of entomological estimates in deaths involving narcotic intoxication has been subject to debate in recent years as few available studies have explored the effects of drugs contained in decomposing tissues on fly colonization and ovipositional behavior, or on the rates of development of carrion-frequenting insects feeding on such food sources. Additionally, relatively few studies have examined the effects of other tissue contaminants, such as toxins or environmental pollutants, on these behaviors and/or the developmental patterns of the insects colonizing such tissues. Studies of the use of carrion-feeding arthropods as alternative toxicological specimens and of the impact that tissue toxins and contaminants have on the development of immature insects feeding on these substances currently comprise the major avenues of exploration in the emerging field of entomotoxicology

Metabonomics and its perspective on forensic medicine / 法医学杂志

Metabolomics is a new study, which use chromatography, mass spectrometry, nuclear magnetic resonance (NMR), capillary electrophoresis (CE) techniques on the cells, organs and other body fluids and metabolites in samples were isolated, purified and testing, re-use bioinformatics tools on the obtained data are analyzed to obtain one or a set of biomarker information. Based on analysis of the literatures in recent years, metabolomics was summarized from history, concept, advantage, methods, application, difficulties and challenges, journals and books, websites, and its application in forensic medicine was forecasted. As a new branch of global system biology, metabonomics developed rapidly, and its perspective on forensic medicine was feasible and very optimistic.

The present study situation and application prospect of nail analysis for abused drugs / 法医学杂志

In forensic toxicology analysis, various types of biological samples have their own special characteristics and scope of applications. In this article, the physiological structure of nails, methods for collecting and pre-processing samples, and for analyzing some poisons and drugs in the nails are reviewed with details. This paper introduces the influence factors of drug abuse of the nails. The prospects of its further applications are concluded based on the research results. Nails, as an unconventional bio-sample without general application, show great potential and advantages in forensic toxicology.

Determination of ethyl glucuronide in blood and urine by LC-MS/MS / 法医学杂志

OBJECTIVE@#To develop a method for determining ethyl glucuronide (EtG) in blood and urine by liquid chromatograph coupled with tandem mass spectrometer (LC-MS/MS).@*METHODS@#After blood and urine de-proteined by acetonitrile, the supernate obtained from a centrifuge was analyzed by LC-MS/MS.@*RESULTS@#Determination limit of EtG in both blood and urine was 0.05 pg/mL, with a linear range of 0.10-5.00 microg/mL (r > 0.999). Accuracy in both matrixes was 95%-109%. Inter- and intra-day RSD were less than 12%. The method showed an excellent performance when it was used to analyze authentic blood and urine samples for EtG.@*CONCLUSION@#The method is capable for blood and urine EtG analysis.

Determination of ethyl glucuronide in blood by GC-MS/MS / 法医学杂志

OBJECTIVE@#To develop a method for determining ethyl glucuronide(EtG) in human blood with gas chromatograph-tandem mass spectrometry (GC-MS/MS).@*METHODS@#Human blood protein was precipitated with acetonitrile. The supernatant was transferred and air flow dried after centrifugated. The residue was derived with N, O-bis (trimethylsilyl)trifluoroacetamide (BSTFA), and analyzed with GC-MS/MS.@*RESULTS@#The detection limit of EtG in blood was 0.05 microg/mL. Calibration curve covered a span from 0.1-10 microg/mL with a good linear relationship (r = 0.999 9). The method showed a excellent performance when was used to authentic blood sample analysis for EtG.@*CONCLUSION@#The method is suitable for blood EtG analysis.

Detection and application of ethyl glucuronide in forensic toxicology / 法医学杂志

Ethyl glucuronide is a specific metabolite of ethanol. There have been plenty of articles referring its pharmacokinetics, detection and application as a specific bio-marker of alcohol intake. This article reviews various analytical methods of EtG, relationship between EtG quantification and ethanol intake, and criteria for determining chronic alcohol abuse, and origin of ethanol found in the cadavers by EtG analysis. EtG has its potential application in forensic toxicology.

Collection, preservation and forwarding of biolgical samples for toxicological analysis in medicolegal autopsy cases : A review.

Collection of proper autopsy specimen is an essential step in the process of toxicology case work¹. Improper collection of these specimens can greatly alter or negate chemical and toxicological analysis. This article is an update about the standard methods of biological specimen collection procedures for toxicological analysis which will be helpful for the forensic pathologist and forensic scientists.