Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC x GC-TOFMS) for drug screening and confirmation

Comprehensive two-dimensional gas chromatography (GC x GC) is applied to analysis of drug standard mixtures containing 78 drugs of interest in forensic samples. For this study, underivatised drugs were employed. While several of the drugs were not detected at the low concentrations employed in the samples, most could be satisfactorily assigned their first and second dimension retentions in the GC x GC retention plane. For this study, time-of-flight mass spectrometry (TOFMS) detection was used. The enhanced separation possible in GC x GC is demonstrated, and typical linearity and apparatus precision are shown for tramadol, diazepam, olanzapine and desipramine using selected qualifier ions. Mass spectral library search quality for the detection of drugs in a selection of authentic forensic cases, along with retention position in the 2D retention plane, is used to support positive identification of the presence of the drugs. The analysis of 'difficult' drugs paracetamol and phenytoin is shown to produce anomalous chromatographic peak shape in the 2D plane, whereas most drugs gave acceptable peak shapes. The GC x GC technique was applied to screening drugs in forensic samples, with either flame ionisation (FID) or TOFMS detection, and compared favourably with conventional single column GC-MS analysis when tested for diazepam in an authentic forensic study.     

Palynology: its position in the field of forensic science

Here we examine the current state of palynology in the field of forensic science. Forensic palynology is discussed with reference to other forensic disciplines to help understand what is required for its progress. Emerging developments are also discussed. Palynomorphs potentially deliver excellent trace evidence, fulfilling the requirements relating to the transfer, persistence, and detection of such evidence. Palynological evidence can provide very powerful investigative and associative evidence. Despite this, the application of palynology to forensic science has had mixed success. There are many anecdotal stories where pollen evidence has had spectacular successes. But it is extremely underutilized in most countries because it is labor-intensive and requires considerable expertise and experience, there is a lack of control over sample collection and inadequate resourcing and funding, and its crime-solving power is not well known. Palynology has been applied to forensic problems in an unstructured way, resulting in a lack of formalized discussion of the underlying principles. As there is renewed questioning of the acceptability of most evidence types in the current legal environment, there is a need for the establishment of palynological evidence through validation-type studies and experimentation, and the implementation of independent proficiency testing.     

Fourier transform infrared analyses of some particulate drug mixtures using a diamond anvil cell with a beam condenser and an infrared microscope.

Although the diamond anvil cell (DAC) has been used in many forensic science laboratories for the analysis of trace evidence, few applications of this technique for the analysis of controlled substances have been reported. This may be due to both an unfamiliarity on the part of forensic drug chemists with this accessory and the nature and quality of spectra that result from use of a DAC on a dispersive instrument. Along with low energy throughput, which results in relatively high noise levels, strong broad diamond absorptions occur. With the use of a Fourier transform infrared instrument, these do not present a problem and nanogram quantities of materials can be analyzed when the DAC is used with an infrared microscope. Since single crystals can be sampled with the DAC, simple physical separations (involving particle-picking) can be used in certain cases to isolate drugs from particulate mixtures for infrared analysis. This method is especially useful for some "difficult" mixtures and residues, and several examples of such analyses involving samples of forensic science interest are presented.     

试论美国纽约市法庭科学工作

纽约市是美国第一大城市,人口众多,经济发达,其法庭科学在国际上也享有声望。纽约市法庭科学部门主要分布在警察局(NYPD)和法医局(OCME)两大机构,警察系统的法庭科学机构主要负责毒品、微量物证、指纹、痕迹、枪弹及文件检验,法医局则进行DNA、毒化、法医病理、法医人类学方面的检验。本文首先介绍美国的警察制度及纽约市警察局概况,然后分别从警察局和法医局两个部门对纽约市法庭科学的部门隶属、部门设置与工作职能情况进行介绍。     

Perceived infallibility of detection dog evidence: implications for juror decision-making

This study focuses on the trust that potential jurors have in unsubstantiated evidence and the implications of such trust for legal decision-making. We examined whether participants’ motivation to think deeply (‘need for cognition,’ NC) and belief in science moderated their trust in potentially fallible detection dog evidence when selecting a verdict in a trial scenario. A detection dog twice indicated the presence of drugs in the scenario, yet no drugs were actually found. Those who chose a guilty verdict without drugs present featured stronger beliefs in detection dog evidence. They were also more confident that a dog alert indicated the presence of drugs, even though the scientific literature actually shows that detection dog evidence is subject to biases and other challenges to reliability. Our findings indicate that an unsubstantiated belief and trust in detection dog evidence may negatively influence juror decision-making, which may, in turn, pose consequences for fairness and justice. Participants believed that detection dogs provide powerful and reliable evidence, and these beliefs were clearly associated with stronger beliefs in science. These findings, therefore, raise serious concerns about jurors’ indiscriminate trust in forensic evidence, be it detection dog evidence or other lines of evidence presented in court.     

Detection of Brodifacoum and other Rodenticides in Drug Mixtures using Thermal Desorption Direct Analysis in Real Time Mass Spectrometry (TD‐DART‐MS)

In recent months, there has been increased reporting of seized drug and toxicology cases containing rodenticides, the active ingredient in rat poisons. Seeing as rodenticides are not scheduled substances, they are not commonly screened for in seized drug analysis. This work investigates the use of TD‐DART‐MS for the simultaneous detection of rodenticides and drugs. Six rodenticides were evaluated, an optimal method was established, and limits of detection in the tens of nanograms were calculated. Additional studies highlight that detection at less than 1% by weight in mixtures with AB‐FUBINACA, cocaine, heroin, or methamphetamine was possible. This work presents an optimized method for detection of these compounds, allowing for the simultaneous detection of drugs and rodenticides, providing drug chemists with a tool for rapid identification of these compounds for forensic or public health purposes.     

Raman identification of drug of abuse particles collected with colored and transparent tapes

Raman microscopy is a useful tool for the analysis of drug particles collected with adhesive tapes. In this work, first, the spectra of thirty drugs of abuse, degradation products, metabolites, and common cutting agent standards were recorded and the Raman bands observed were summarized providing the forensic analyst useful information for the identification of drug evidence. Then, the collection of different drug particles by a fingerprint lifting tape commonly used to remove and store fingerprints and fibers, and a white and green packaging tape, followed by the subsequent identification of the drugs by confocal Raman spectroscopy was performed. The particles were analyzed on top of the tapes, trapped between glass slides and the tapes, trapped in the tape folded over itself in the case of the transparent tape, and after folding and unfolding the tape in the case of the colored tape. The results obtained by the different approaches show that both tapes did not compromise the drugs spectra. However, the use of transparent tape is preferred because this tape allows the previous visual detection of the particles. Finally, several drug and sugar particles were spread over a clean table and inside a pocket, and the particles were collected with transparent tape and then properly identified. Although good results were obtained in both cases, the amount of fibers and other substances present in the collection area made the previous detection of the particles difficult and increases the analysis time.     

唾液及含唾液检材的DNA分析

提取160份唾液及含唾液的检材中的DNA，并根据DNA的质和量进行了DNA指纹图检验或应用聚合酶链反应（PCR）进行了DNA分型。结果表明，唾液和含唾液检材是很好的DNA来源．对其进行DNA分析是可行的。     

Optimisation of choline testing using Florence Iodine reagent,including comparative sensitivity and specificity with PSA and AP tests

The detection of semen in forensic science is essential in cases of sexual assault but can be problematic in the absence of spermatozoa. Choline is known to occur in high concentrations in seminal fluid and the Florence Iodine test for its detection has been used in forensic science for many years, however very little is documented regarding its sensitivity and specificity in forensic casework. This paper describes the optimisation of the choline Florence Iodine test (FI) and investigates the sensitivity and specificity of the test against different body fluids, food and drink substances, cleaning products and laboratory chemicals. Comparative testing against Acid Phosphatase (AP) and Prostate Specific Antigen (PSA Seratec®) tests is described and shows that the FI test has greater specificity than the PSA test which cross reacts with a number of body fluids.     

Determination of disperse dyes on polyester fibers by UHPLC–Orbitrap MS

The determination of fiber dyes is important in forensic investigations. Although a variety of fiber dyes detection methods have been established, the sensitive and accurate determination of trace fiber dyes remains a challenge due to the possible interferences caused by complex environmental matrix and various fiber additives. Orbitrap mass spectrometry (Orbitrap MS) is a type of high-resolution mass spectrometry with high qualitative accuracy and detection sensitivity which highly meet the identification requirements of fiber dyes in real cases. However, the application of Orbitrap MS in fiber dye analysis is limited. In this regard, this study used polyester fiber, which is the most commonly-found fiber in forensic cases, as a model and established a UHPLC–Orbitrap MS method to analyze disperse dyes on polyester fibers. Using the optimized UHPLC–Orbitrap MS method, nine disperse dyes were accurately identified and well separated, and the limits of detection ranged between 0.1 ng/mL and 5.0 ng/mL. The developed method was applied to analyze actual fiber samples, and dyes from single fibers of 1 mm in length could be accurately detected. The established method is sensitive, accurate, and demonstrates good application prospects.     

K2 Toxicity: Fatal Case of Psychiatric Complications Following AM2201 Exposure

Limited forensic and clinical experience and the lack of confirmatory testing strategies for synthetic cannabinoids (SC) prevent adequate characterization of SC toxicity and the potential impact on public health. A statewide surveillance system identified a fatality involving a 23‐year‐old man found with a large stab wound to the neck following use of a SC product suspected of containing AM2201. Analytical testing for common SCs, SC metabolites, routine drugs of abuse, and over‐the‐counter medications was performed on heart blood obtained at autopsy. Additionally, assays were performed on the SC raw material and drug paraphernalia found on the decedent. High concentrations of AM2201 were detected in all samples. AM2201 metabolites were detected in postmortem blood. Other than a trace amount of JWH‐073 found in smoke residue, no other substances were detected. Psychiatric complications including self‐induced, lethal trauma can occur after the use of SC products.     

Identification of heroin in street doses using 1D-TOCSY nuclear magnetic resonance

Heroin street doses are complex mixtures commonly analyzed in forensic laboratories. Identification of the illicit substance in these street doses is among the primary analytical tasks of a forensic laboratory. We demonstrate that the one-dimensional ID-TOCSY NMR experiment permits identification of heroin in standard mixtures containing up to ten or more different components. This method produces an easily-identified and effective "fingerprint" for heroin within a mixture of other substances. The method has been successfully tested as a tool for identification of heroin in street doses from police casework in Israel. This NMR technique is robust and quick (a measurement can be carried out in 10-15 min), and it does not require any preliminary physical or chemical treatments of the sample to be examined, due to the effective spectroscopic "filtering" of the interfering components. The ID-TOCSY NMR method can potentially be used in combination with additional analytical methods as a routine tool in forensic laboratories to positively identify heroin for court purposes.     

The use of simulated crime scenes in teaching undergraduate forensic sciences: Implementing an active learning approach to forensics

Incorporating a simulated crime scene into one’s pedagogy in forensic science undergraduate courses allows students the opportunity to experience a realistic scenario while demonstrating their knowledge and enhancing their critical thinking skills. The purpose of this paper is to examine an active learning approach to using simulated crime scenes to provide an impactful learning experience for students. While potentially challenging for the instructor, constructing a crime scene scenario can provide students with hands-on practical experience while helping to dispel forensic science misconceptions. Through many years of creating crime scenes, best practices for using such high impact activities in forensic science courses are described in detail, including preparatory exercises that culminate in the final crime scene scenario, considerations in preparing and constructing a crime scene activity, and supervising and assessing students once the activity begins. Three major challenges to implementing active learning exercises such as simulated crime scenes in undergraduate forensic science programs include high workload for instructors, limited supplies, and lack of suitable facilities. Workload solutions include instructors and departments considering the cost and benefit of course releases to improve curriculum and student enrollment. Supplies and facilities solutions involve innovation in reuse and repurposing of supplies, and instructor flexibility in using classroom and outdoor spaces.     

Applications of a transportable Raman spectrometer for the in situ detection of controlled substances at border controls

A transportable Raman spectrometer was tested for the detection of illicit drugs seized during border controls. In a first step, the analysis methodology was optimized using reference substances such as diacetylmorphine (heroin), cocaine and amphetamine (as powder or liquid forms). Adequate focalisation distance and times of analysis, influence of daylight and artificial light sources, repeatability and limits of detection were studied. In a second step, the applications and limitations of the technique to detect the illicit substances in different mixtures and containers were evaluated. Transportable Raman spectroscopy was found to be adequate for a rapid screen of liquids and powders for the detection and identification of controlled substances. Additionally, it had the advantage over other portable techniques, such as ion mobility spectrometry, of being non-destructive and capable of rapid analysis of large quantities of substances through containers such as plastic bags and glass bottles.     

Current approaches to analysis of narcotic drugs in biological substances

A method of analysis of basic narcotic drugs in urine is described. It consists in isolation by solid phase extraction, derivation and identification by gas chromatography with mass-selective detector. The approaches applied in the above method can be used for analysis of narcotic drugs undetectable by preliminary investigations as well as for urine examination for pharmacological or other biologically active substances.     

溺死的法医学检验现状及进展

本文概括阐述了近年来,国内外学者将硅藻的检验、内脏异物颗粒和微量元素成分的检验、血液化学的检验、电子显微镜的观察等方法应用于溺死的诊断,试图为溺死的法医学鉴定提供准确的诊断指标。     

宏基因组学在法医学鉴定中的应用

随着分子生物学与基因组学的发展,宏基因组学在法医学与法医学鉴定中逐渐扮演着重要的角色。近年来,宏基因组学作为研究环境微生物菌群构成与多样性、各成员之间相互关系及与环境之间相互关系的分支学科,在法医学鉴定相关领域的应用也逐渐兴起,并带来了新的契机。本文对宏基因组学研究策略及其在法医学鉴定中个体识别、案发现场生物斑迹来源鉴定及药物滥用检测等方面的应用现状进行了综述,旨在进一步阐明宏基因组学在法医学中的作用与应用价值。     

A fatal overdose of the ergot derivative cabergoline

A 79-year-old woman, with Parkinson's disease treated with cabergoline, was admitted to a hospital due to jaundice and weakness. She was found confused, absent minded, and died after 2 weeks. Autopsy showed an extrahepatic bile duct adenocarcinoma with spread to the gall bladder, the liver, and regional lymphnodes. While cleaning the hospital bed after her death, the nurses found several tablets hidden in the bed. Biological samples obtained at the autopsy were screened for common drugs and narcotics. Several drugs such as buprenorphine, codeine, paracetamol, and propranolol were detected in the blood at therapeutic levels. A method to determine cabergoline in whole blood and other forensic matrices was developed, and further investigations determined cabergoline concentrations in whole blood and liver tissue of 94 and 3100 microg/kg, respectively. The blood concentration was 100 times above the therapeutic level reported on cabergoline in plasma and in combination with her symptoms, suggest she took a fatal overdose of cabergoline.     

拉曼光谱法鉴别常见毒品

目的建立一种识别毒品与其它常见白色物质的方法。方法使用激光显微拉曼光谱法对7种毒品和5种白色粉末进行了分析。结果7种常见毒品均有丰富的拉曼位移峰,可以通过其位移峰峰位的不同区分不同成分的毒品。另外,通过拉曼位移峰的峰位,还可以将7种常见毒品与5种常见白色粉末区分开来。结论拉曼光谱法适用于快速准确地识别毒品。