Hair Analysis of Mammals of Brazilian Wildlife for Forensic Purposes

Wildlife trafficking is classified as the fourth largest illegal commerce in the world. Taxonomic identification of wildlife is an ordinary process for forensics experts. The aim of this study was to analyze animal’s hair from Brazilian’s wildlife through microscopic and compare morphology of bristle among species analyzed. Hair samples of nine species were analyzed. Glass slides were analyzed through optical microscopy and following measurements were obtained: total length, medulla diameter, overall diameter and overall ratio diameter of the medulla’s diameter. The images obtained at identification of animals through the morphology of hair and the statistics analysis corroborates in favor for the validation of the technique.

Current status of hair analysis in forensic toxicology in China

Hair analysis has been mainly used to document drug use history in abusers,drug-facilitated crime cases,doping control analysis and postmortem toxicology in the fields of forensic toxicology,clinical toxicology,and doping control.Hair analysis has also gained more attention in the last 30 years in China.Relevant technology has been promoted as more research has appeared concerning hair analysis,and consensus has been sought among forensic toxicologists regarding aspects such as hair decontamination treatment,detection of abused substances in hair,segmental hair analysis and interpretation of analytical results.However,there are still some limitations in the estimation of drug intake time and frequency by segmental hair analysis due to the different growth cycles evident within a bundle of hairs,the drug incorporation mechanism and sampling errors.Microsampling and imaging mass spectrometry(iMS)technology based on a single hair may be a good choice to estimate drug intake time more accurately.Analysis of hair root samples may also be used to document acute poisoning in postmortem toxicology,and the analysis of the hair shaft can document long-term use of drugs depending on the length of the hair being evaluated.

Segmental hair analysis for flunitrazepam and 7-aminoflunitrazepam in users:a comparison to existing literature

The availability of more quantitative data on flunitrazepam(FLU)and 7-aminoflunitrazepam(7AF)would aid in obtaining a better understanding of the interpretation of FLU concentrations in human hair.The purpose of this study was to provide concentrations of FLU and 7AF in hair segments of 22 FLU users.Quantitative data regarding hair concentrations of FLU and 7AF from various types of cases were also reviewed to give a comprehensive overview of the comparability of different studies.Three to six 1 cm segments of scalp hair from 22 FLU users were analyzed by a liquid chromatography–tandem mass spectrometry(LC–MS/MS)method.FLU and its metabolite were confirmed in the hair segments from all cases.Concentrations of FLU and 7AF in the segments ranged from 0.01–0.16 ng/mg(median of 0.03)and 0.01–0.34 ng/mg(median of 0.09),respectively.Most cases had FLU and 7AF distributions along the hair segments that were suggestive of repeated drug use.A summary of the published concentrations gives valuable data and can assist forensic investigators in their estimations of drug use history and patterns.

Hair Analysis Could Reveal Recent Travels

仅凭一根头发就能判断出嫌疑犯曾到过哪些地方或避难所中的难民来自何处。英国科学家最近做出的一项研究让大名鼎鼎的福尔摩斯也自叹弗如。

Uncertainty Estimation for the Determination of Trace Heavy Metals in Human Hair by Flame and Electrothermal Atomic Absorption Spectrometry

Trace element analysis on hair samples has been widely used to assess wildlife and human exposure to different contaminants present in the environment or at the workplace. Pollutants due to the presence of toxic metals in environment not only enter the body by breading, water, and foodstuff accumulates in hair, but they could be adsorbed directly on the hair from environment. In order to remove adsorbed elements and thus determine the internally bound elements correctly, hair sample must be washed. In the present work, we propose uncertainty estimation for the analytical results that are obtained from determination of cadmium, lead, copper, iron, manganese and nickel in human hair by flame and electrothermal atomic absorption spectrometry （FAAS and ETAAS）. To estimate the uncertainty of analytical result obtained, two types of bias are calculated in the assessment of trueness： a proportional bias and a constant bias. Nested design was applied for calculating proportional bias and Youden method to calculate the constant bias. The results we obtained for proportional bias are calculated from spiked samples. In this case, the concentration found is plotted against the concentration added and the slop of standard addition curve is an estimate of the method recovery. Estimated method of average recovery in human hair is： （1.019 ±0.026）, （0.918 ±0.014）, （1.073±0.016）, （1.0597± 0.017）, （1.073± 0.020） and （0.934± 0.117） for Cd, Pb, Mn, Ni, Fe and Cu respectively.

Determination of amphetamines,ketamine and their metabolites in hair with high-speed grinding and solid-phase microextraction followed by LC-MS

A novel hair sample pre-treatment method based on high-speed grinding and solid-phase microextraction(SPME)had been applied for the determination of amphetamines,ketamine and their metabolites in hair samples by liquid chromatography mass spectrometry(LC-MS).A 20mg sample of hair was ground with 2 mL of saturated sodium carbonate solution using a high-efficiency hair grinder with 70 Hz osillation for 2min at 4℃.After centrifuging,1.5mL of the supernatant was transferred and treated with SPME by direct immersion(DI-SPME).The target analytes extracted by fibre were desorbed and analysed using LC-MS.Under the optimum conditions,a recovery of 90.2%-95.8%was obtained for all analytes.The analytical method was linear for all analytes in the range from 0.2 to 10 ng/mg with the correlation coefficient ranging from 0.9985 to 0.9993.The detection limits for all analytes were estimated to be 0.067 ng/mg.The accuracy(mean relative error)was within±6.9%and the precision(relative standard error)was less than 6.8%.The combination of high-speed grinding of hair and SPME had the advantages of being easy to perform,environment-friendly and high in detection sensitivity.The proposed method offered an altermative ana lytical approach for the sensitive detection of drugs in hair samples for forensic purposes.

Determination of barbiturates in hair samples by using a validated UHPLC-HRMS method: application in investigation of drug-facilitated sexual assault

In recent years,benzodiazepines and benzodiazepine-like drugs are the most common substances associated with drug-facilitated sexual assaults(DFSA);however,barbiturates are also detected occasionally.Segmental hair analysis provides useful information on the historic pattern of drug use,enabling differentiation between single exposure in DFSA cases and chronic use.However,sensitive and specific methods for barbiturate analysis in hair samples are needed.Herein,we present an ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry(UHPLC-HRMS)method for qualitative and quantitative determination of seven barbiturates in hair samples.Firstly,a hair strand was decontaminated and then freeze-milled in liquid nitrogen.Next,50mg of powdered hair was extracted with methanol in an ultrasonic bath for 10 min in the presence of 10 ng phenobarbital-d5.The supernatant was dried under nitrogen gas,and the pellet was dissolved in 100 μL mobile phase.Afterwards,10 μL of the suspension was injected into the UHPLC-HRMS system.The present method involved two UHPLC conditions for determination of barbiturates(I)and identification of the structural isomers amobarbital and pentobarbital(II).This method showed satisfactory linearity in a range of 0.02–20.00 ng/mg for UHPLC conditions I and II,both with a high determination coefficient(0.9991–0.9999).The selectivity,intra-and interday precision,accuracy and matrix effect of the method were acceptable.Next,the validated method was applied to investigate an authentic DFSA case.Hair samples(black,approximate 25cm long)were collected 3 months after the assault,and the proximal segments(0–5 cm from the root;each segment was 1 cm long)were analysed.Amobarbital was detected at a concentration of<LOQ(limit of quantification)and 0.09 ng/mg in the second and third 1-cm hair segment but not in the other segments.Thus,our method was successful in determining barbiturate concentration in human hair after a single-dose exposure,showing its potential for application in the investigation of DFSA cases.

Wildlife forensic examination in Russia:the practice and perspectives

Two case studies are described which show application of forensic expertise to establish important circumstances related to the investigation of the crimes against wildlife flora and fauna.Forensic study of the animal hair is a method for investigation of the crimes against wildlife objects which is used more frequently during the recent years.The perspectives of development of the new branch of forensic research in Russia are formulated,and the proposals and recommendations for developing the Eurasian wildlife flora and fauna network are formulated in this article.