Determination of organosilicon oxide polymers in tissue by atomic absorption spectroscopy using HGA graphite furnace

A simple method of extraction and determination of organosilicon oxide polymers (silicones) in 0.1-0.5 g of formalin fixed tissue by atomic absorption spectroscopy is described. Before the tissue is extracted with n-heptane, it is dried in a desiccator containing concentrated sulphuric acid. The graphite tubes in the HGA graphite furnace are tubes with L'vov platform. The evaporation of n-heptane and a part of the charing of the tissue extract in the tube are done in the presence of oxygen (air). The significance of the employment of L'vov platform and the presence of oxygen are discussed. The methods detection limit (2 X S.D.) is about 0.009 microgram silicon/ml tissue extract which corresponds to about 0.5 microgram polydimethylsiloxane/g tissue.     

Validation of a high performance liquid chromatographic method for alpha amanitin determination in urine

The objective of the present study was to develop and validate a liquid chromatographic method with electrochemical detection to measure alpha amanitin concentrations in urine after sample pretreatment with double mechanism (reversed phase/cation exchange) solid-phase extraction cartridges. The urine samples (10 ml) were purified and concentrated to 1 ml with elimination of matrix contaminants. The extracts were then separated by isocratic reversed-phase chromatography using a C18 column (4.6 mm×25 cm) with a mobile phase composed of 0.005 M phosphate buffer (pH 7.2) and acetonitrile (90:10). Coulometric detection was performed by applying an oxidation potential of +500 mV to a porous graphite electrode in a low-volume analytical cell. The limit of quantitation was 10 ng/ml with a signal-to-noise ratio=25. The linearity studied on spiked urine was satisfactory (r=0.9966) from 10 ng/ml to 200 ng/ml. The average extraction recovery of alpha amanitin was 78%, determined using spiked urine samples ranging from 10–300 ng/ml. The intra-assay precision was checked at 10, 50 and 100 ng/ml levels (n=10) in spiked urine samples, with resulting coefficients of variation of 3.6%, 2% and 1.5%, respectively.     

Characteristics of electrically injured skin from human hand tissue samples using Fourier transform infrared microspectroscopy

This technical note describes a method for distinguishing normal skin tissue samples from those electrically injured by Fourier transform infrared microspectroscopy (FTIR MSP). Furthermore, the infrared spectral features of electrically injured cells and tissues were evaluated to identify molecular changes in epidermal cells. In the present study, 20 human hand tissue samples were evaluated macroscopically and histopathologically. The electrically injured skin samples were subdivided into 2 regions [normal cell regions (NCRs) and polarized cell regions (PCRs)] and 14 major spectral absorption bands were selected. The spectral results showed that the band absorbance at 1080, 1126, 1172, 1242, 1307, 1403, 1456, 1541, 2852, 2925, 2957, 3075, and 3300 cm^− 1 increased significantly both in the stratum and non-stratum corneum of the PCRs in electrically injured skin tissues samples. No significant difference was found between normal skin and the NCR of the electrically injured skin samples. The band absorbance ratios of A₁₁₇₂/A₁₁₂₆, A₁₄₅₆/A₁₄₀₃, and A₂₉₂₅/A₂₉₅₇ were significantly increased, whereas the A₁₆₅₂/A₁₅₄₁ ratio was decreased in the PCR of the stratum corneum and non-stratum corneum. Baseline changes from 4000 to near 1737 cm^− 1 were observed in the spectra of the electrically injured skin samples, which were interpreted in terms of the pathological process involved in electrical injury. FTIR-MSP presents a useful method to provide objective spectral markers for the assisted diagnosis of electrical marks.     

Detection and confirmation of fentanyls in high clay-content soil by electron ionization gas chromatography-mass spectrometry

Detection of illicit drugs in the environment, particularly in soils, often suggests the present or past location of a clandestine production center for these substances. Thus, development of efficient methods for the analysis and detection of these chemicals is of paramount importance in the field of chemical forensics. In this work, a method involving the extraction and retrospective confirmation of fentanyl, acetylfentanyl, thiofentanyl, and acetylthiofentanyl using trichloroethoxycarbonylation chemistry in a high clay-content soil is presented. The soil was spiked separately with each fentanyl at two concentrations (1 and 10 μg/g) and their extraction accomplished using ethyl acetate and aqueous NH₄OH (pH ~ 11.4) with extraction recoveries ranging from ~56% to 82% for the high-concentration (10 μg/g) samples while ranging from ~68% to 83% for the low-concentration (1 μg/g) samples. After their extraction, residues containing each fentanyl were reacted with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl) to generate two unique and predictable products from each opioid that can be used to retrospectively confirm their presence and identity using EI-GC-MS. The method's limit of detection (MDL/LOD) for Troc-norfentanyl and Troc-noracetylfentanyl were estimated to be 29.4 and 31.8 ng/mL in the organic extracts. In addition, the method's limit of quantitation for Troc-norfentanyl and Troc-noracetylfentanyl were determined to be 88.2 and 95.5 ng/mL, respectively. Collectively, the results presented herein strengthen the use of chloroformate chemistry as an additional chemical tool to confirm the presence of these highly toxic and lethal substances in the environment.     

Phenibut screening and quantification with liquid chromatography–tandem mass spectrometry and its application to driving cases

An analytical strategy for identification by an LC–MS/MS multitarget screening method and a suitable LC–MS/MS based quantification were developed for the psychotropic drug phenibut. The samples analyzed were collected during traffic control and were associated with driving under the influence of drugs. A positive sample for phenibut was identified in a single case of driving under the influence. The quantification revealed a drug concentration of 1.9 μg/mL. An interaction with blood alcohol (BAC = 0.10%) was discussed as the explanation of the way of driving and deficit manifestations observed (swaying, nystagmus, quivering of the eyelid, and reddened eyes). According to the available information, the quantified phenibut concentration could be explained by an intake of four tablets (self-reported) during the day containing 250 mg of the drug. Chromatography was performed with a Luna 5 μm C18 (2) 100 A, 150 mm × 2 mm analytical column, and a buffer system consisted of 10 mM ammonium acetate and 0.1% acetic acid (v/v) included in mobile phases marked as A (H₂O/methanol = 95/5, v/v) and B (H₂O/methanol = 3/97, v/v). An effective limit of detection (LOD = 0.002 μg/mL) could be achieved for the multitarget screening method. The quantification of phenibut was performed on a second LC–MS/MS system with LOD/LOQ values of 0.22/0.40 μg/mL. Since phenibut quantification data are rare, the presented information can be used with caution for evaluation of positive cases in the future.     

Detection of toluene in an adipoceratous body

A 24-year-old male was found dead in a car left in a river for about 3 months. The cadaver was almost adipoceratous and autopsy findings revealed that there were neither remarkable injuries nor lethal diseases. Toluene, ethanol, 1-propanol, 2-propanol, 1-butanol, dimethyl sulfide, dimethyl disulfide, isovaleraldehyde and n-butyl n-butyrate were detected in the specimens collected at the autopsy by head space gas chromatography/mass spectrometry (GC/MS). The toluene concentrations (μg/g) were 31.0 in brain, 10.6 in liver, 5.4 in kidney, 15.0 in skeletal muscle and 187.1 in adipose tissue. The presence of diatom in lung, liver and kidney suggested that death was caused by drowning. So far as we know, this is the first report of detection of toluene in an adipoceratous body.     

Practical experiences with the determination of cadaver age by evaluation of bacterial metabolic products

In an experiment a corpse had been kept at room temperature (16 degrees-23 degrees C) for 1163 h. At regular intervals brain samples were taken and the content of free amino acids and related compounds was determined by column chromatography. It could be demonstrated that in a period of 4-20 days postmortem the age of the corpse could be calculated from the concentrations of alpha-aminobutyrate (ABU), gamma-aminobutyrate (GABA), and glutamic acid (GLU) in brain employing the previously [5] presented formula: (formula; see text) T is the postmortem time lapse (days). ABU, GABA, and GLU are the concentrations (mumol/g) wet tissue of the corresponding amino acids. During this postmortem interval there is nearly a linear correlation; from this interval a correct assignment between concentrations and time cannot be given. The determination method is in the range of about 15 degrees-25 degrees C (guarantees bacterial growth and metabolism) independent of ambient temperature. The brain samples (cortex or parts of the putrified brain mush) can be taken without any special precaution during normal autopsy. The results of the experiment (in Fig. 1) were supported by some practical cases where the time lapse since death was well (in Fig. 1) or reasonably (in Fig. 1) known. These results suggest that this method allows in many cases the determination of the age of a corpse found in a warm environment (approximately 15 degrees-25 degrees C) approximately 4-20 days after death.     

A Rare Case of Poisoning with a Volatile Substance: Quantitative Determination of n‐Butane in Postmortem Tissue

Poisoning with volatile substances remains exceptional. Authors report the case of a married couple who were found in a car with a butane gas bottle: the woman was dead and her husband alleged it was an unsuccessful suicide pact. A specific research of volatile substances on postmortem samples with headspace gas chromatography–mass spectrometry following a quantitative determination was performed. The n‐butane concentrations detected were composed of 610 μg/L (cardiac blood), 50 μg/kg (brain), 134 μg/kg (lungs), 285 μg/kg (liver), and 4090 μg/kg (heart) and were compatible with the rare lethal concentrations evoked in the literature. The cause of death was determined to be asphyxiation through n‐butane criminal poisoning. Authors recommendation therefore is to take samples immediately and place them in properly sealed containers and hence analyzing the samples as soon as possible after collecting them or storing them under ?30°C (?22°F) if analyses cannot be performed immediately.     

The estimation of the time of death by non-protein nitrogen (NPN) in cadaveric materials. Report 3: Multiple regression analysis of NPN values in human cadaveric materials

The non-protein nitrogen (NPN) values in brain, lung, liver, and kidney in 79 autopsy cases were determined according to the Micro-Kjeldahl Nessler method. Multiple regression analysis of the data was performed with every possible combination of the time of death and the NPN values in the tissues.The brain NPN showed the best correlation with the postmortem time (r = 0.673), whereas the other correlations were less satisfactory (lung r = 0.422, liver r = 0.397, and kidney r = 0.379, respectively). However, multiple combinations of each tissue NPN value proved to give better correlation coefficients and smaller errors of the estimated time of death.The practical significance of the tissue NPN as a postmortem biochemical indicator of the time of death and the multiple regression analysis of such indicators were extensively discussed in this report.     

On the consequences of ignoring genetic influences in criminological research

Purpose

Many criminological scholars explore the social causes of crime while giving little consideration to the possibility that genetic factors underlie the observed associations. Indeed, the standard social science method (SSSM) assumes genetic influences do not confound the association between X and Y. Yet, a nascent stream of evidence has questioned the validity of this approach by revealing many criminological variables are at least partially affected by genetic influences. As a result, a substantial proportion of the literature may be misspecified due to uncontrolled genetic factors. No effort has been made to directly estimate the extent to which genetic confounding has biased the associations presented in criminological studies.

Methods

The present study seeks to address this issue by drawing on simulated datasets.

Results/Conclusions

Results suggest genetic confounding may account for a negligible portion of the relationship between X and Y when their correlation (r_yx) is larger than the correlation between genetic factors and Y (i.e., r_yx > r_yg). Genetic confounding appears to be much more problematic when the correlation between X and Y is in the moderate-to-small range (e.g., r_yx = .20) and the genetic effect is in the moderate-to-large range (e.g., r_yg ≥ .30).     

Drug accumulation and elimination in Calliphora vicina larvae

Calliphora vicina larvae were fed on drug-laden muscle from three suicides involving amitriptyline, temazepam and a combination of trazodone and trimipramine; triplicate daily harvestings were analysed. The limit of detection for all four drugs was 0.01 μg drug/g larvae. Mean drug concentrations (μg/g) in the initial muscle were: amitriptyline, 2.68; temazepam, 4.04; trazodone, 21.56; and trimipramine, 19.58. Larval rearings for days 4–8 (15 larval samples per drug) had mean and ranges of drug concentrations (μg/g) of 0.10 (r, 0.02–0.24) for amitriptyline; 0.52 (r, 0.26–0.78) for temazepam; 0.13 (r, 0.05–0.32) for trazodone; and 0.28 (r, 0.10–0.59) for trimipramine. After day 8 there was a precipitous fall in larval drug concentrations associated with pupariation. At day 11 ranges of drug concentrations (μg/g) were: amitriptyline, < 0.01-0.01; temazepam, 0.01–0.08; trazodone, < 0.01-0.01; and trimipramine, 0.04-0.04. Day 16 pupae had corresponding ranges (μg/g) of < 0.01, < 0.01-0.01, < 0.01 and < 0.01–0.02. Transfer to drug-free food at day 5 led to similar falls in drug concentrations (μg/g) from day 5 to day 6: 0.08-0.03 for amitriptyline, 0.61-0.09 for temazepam, 0.13-0.01 for trazodone, and 0.30-0.02 for trimipramine. The results show considerable variation in larval drug concentrations, both at the same developmental stage and at different stages of the life cycle, under conditions which closely reflect case situations. In practice, the precipitous decrease in drug concentrations in non-feeding larvae and at pupariation make it desirable to sample only larvae actively feeding on a corpse.     

Measurement of Uncertainty for Aqueous Ethanol Wet‐Bath Simulator Solutions Used with Evidential Breath Testing Instruments

Aqueous ethanol wet‐bath simulator solutions are used to perform calibration adjustments, calibration checks, proficiency testing, and inspection of breath alcohol instruments. The Toxicology Bureau of the New Mexico Department of Health has conducted a study to estimate a measurement of uncertainty for the preparation and testing of these wet‐bath simulator solutions. The measurand is identified as the mass concentration of ethanol (g/100 mL) determined through dual capillary column headspace gas chromatography with flame ionization detector analysis. Three groups were used in the estimation of the aqueous ethanol wet‐bath simulator solutions uncertainty: GC calibration adjustment, GC analytical, and certified reference material. The standard uncertainties for these uncertainty sources were combined using the method of root‐sum‐squares to give u_c = 0.8598%. The combined standard uncertainty was expanded to U = 1.7% to reflect a confidence level of 95% using a coverage factor of 2. This estimation applies to all aqueous ethanol wet‐bath simulator solution concentrations produced by this laboratory.     

A Bi-level Framework for Understanding Prisoner Victimization

Objectives

To present and test an opportunity perspective on prison inmate victimization.

Methods

Stratified random samples of inmates (n ₁ = 5,640) were selected from Ohio and Kentucky prisons (n ₂ = 46). Bi-level models of the prevalence of assaults and thefts were estimated. Predictors included indicators of inmate routines/guardianship, target antagonism, and target vulnerability at the individual level, and several indicators of guardianship at the facility level.

Results

Assaults were more common among inmates with certain routines and characteristics that might have increased their odds of being victimized (e.g., less time spent in recreation; committed violence themselves during incarceration), and higher levels of assaults characterized environments with lower levels of guardianship (e.g., architectural designs with more “blind spots”, larger populations, and less rigorous rule enforcement as perceived by correctional officers). Similar findings emerged for thefts in addition to stronger individual level effects in prisons with weaker guardianship (e.g., ethnic group differences in the risk of theft were greater in facilities with larger populations and less rigorous rule enforcement).

Conclusions

The study produced evidence favoring a bi-level opportunity perspective of inmate victimization, with some unique differences in the relevance of particular concepts between prison and non-prison contexts.     

海洛因毒品中残留有机溶剂的检测方法与结果分析

目的建立固体海洛因毒品中残留有机溶剂的顶空-气相色谱和顶空-气相色谱-质谱联用检测方法。方法采用干法和湿法处理42份样品,密封后90℃加热振荡20min,抽取顶空气体用气相色谱法（DB-WAX毛细柱,30m×0.25mm,0.25μm）和气相色谱-质谱联用法（HP-5MS毛细柱,30m×0.25mm,0.25μm）检测,以已知17种有机溶剂外标法定性。在样品中加水后检测,根据峰高估算5种共有成分的含量。结果在42份海洛因毒品中检出乙酸、乙醚、乙醇、乙酸乙酯、乙醛、三氯甲烷等12种有机溶剂成分,5种主要共有成分相对含量有差别。结论本研究建立的检测方法快速、简便,定性可靠,可用于固体海洛因毒品的来源与批次分析。     

Fatal Intoxication with Toluene Due to Inhalation of Glue

Two cases of fatal intoxications with toluene due to glue sniffing are described. In case 1, the autopsy did not indicate cause of death, while in case 2, the cause of death was determined to possibly be due to mechanical asphyxia by drowning. As the decedents had a history of glue sniffing, toxicological analyses were performed. Using gas chromatography with flame ionization detector and gas chromatography/mass spectrometry (GC/MS) with headspace method, toluene was detected in biological samples. Toluene ranged from 3.81 to 20.97 μg/g, with the highest concentrations observed in liver and brain (13.82–20.97 μg/g) in both cases. Based upon this data, the cause of death in both cases was determined to be toluene poisoning. Toxicological investigations are extremely important and should be considered mandatory in all deaths thought to be due to volatile substance abuse, as well as all deaths that are thought to be due to poisoning in young people.     

Practical benzylation of N,N-substituted ethanolamines related to chemical warfare agents for analysis and detection by electron ionization gas chromatography–mass spectrometry

The benzylation of three low molecular weight N,N-disubstituted ethanolamines related to chemical warfare agents (CWAs) to furnish derivatives with improved gas chromatography-mass spectrometry (GC-MS) profiles is described. Due to their low molecular weight and polar nature, N,N-disubstituted ethanolamines are notoriously difficult to detect by routine GC-MS analyses during Organisation for the Prohibition of Chemical Weapons (OPCW) proficiency tests (PTs), particularly in scenarios when they are present at low levels (~1–10 ppm) amidst more abundant interferences. Our studies revealed that the optimal derivatization conditions involved the treatment of the ethanolamine with benzyl bromide in the presence of an inorganic base (e.g., Na₂CO₃) in dichloromethane at 55°C for 2 h. This optimized set of conditions was then successfully applied to the derivatization of N,N-dimethylethanolamine, N,N-diethylethanolamine and N,N-diisopropylethanolamine present separately at 1 and 10 μg/mL concentrations in a glycerol-rich matrix sample featured in the 48th OPCW PT. The benzylated derivatives of the three ethanolamines possessed retention times long enough to clear the massive glycerol-containing matrix interferences. The protocol herein is introduced as an alternative method for derivatization of these CWA and pharmaceutically important species and should find broad applicability in laboratories where routine forensic analysis is carried out.     

A fast ultrasound-assisted extraction procedure for trace elements determination in hair samples by ICP-MS for forensic analysis

An ultrasound-assisted extraction method is proposed for the determination of trace elements in hair samples by inductively coupled plasma-mass spectrometry (ICP-MS) for forensic investigation. Prior to analysis, 25 mg of hair samples were accurately weighed into (15 mL) conical tubes. Then, 2 mL of 20% HNO₃ is added to the samples, sonicated at 2 min (50 W, 100% amplitude), and then further diluted to 10 mL with Milli-Q water. Resulted diluted slurries are centrifuged and the analytes are directly determined in the supernatant. Calibrations against aqueous solutions were carried out with rhodium as internal standard. The method was successfully applied for the extraction of Al, As, Ba, Be, Cd, Co, Cr, Cu, Mn, Pb, Tl, U, V and Zn with a method detection limit (3 s, n = 20) of 0.1, 0.4, 0.2, 0.09, 0.08, 0.04, 0.1, 2.9, 1.0, 0.9, 0.04, 0.05, 0.1 and 4.2 ng/g, respectively. Method accuracy is traceable to Certified Reference Materials (CRMs) 85 and 86 human hair from the International Atomic Energy Agency (IAEA). Additional validation data are provided based on the analysis of hair samples from the trace elements intercomparison program operated by the Institut National de Sante’ Publique du Quebec, Canada. The proposed method is very simple and can be applied for forensic purposes with the elimination of sample digestion step prior to analysis. Then, a considerable improvement in the sample throughput is archived with the use of the proposed method.     

Cyanide and amygdalin as indicators of the presence of bitter almonds in imported raw almonds

Abstract: Consumer complaints received by the U.S. Food and Drug Administration in August 2010 about raw organic almonds tasting “bitter” opened an investigation into the presence of bitter almonds in the imported product. Bitter almonds (Prunus amygdalus) contain the cyanogenic glucoside amygdalin, which hydrolyzes to produce cyanide. Ultraviolet–visible spectrophotometry was used to detect and quantitate cyanide, and liquid chromatography‐mass spectrometry was utilized to detect amygdalin in the submitted samples. Control bitter almonds were found to contain 1.4 mg cyanide/g and an estimated level of 20–25 mg amygdalin/g. The questioned samples contained between 14 and 42 μg cyanide/g and were positive for the presence of amygdalin. Sweet almonds were found to be negative for both compounds, at levels of detection of 4 μg cyanide/g and 200 μg amygdalin/g.