Analysis and discrimination of electrical tapes: Part I. Adhesives

This study involved the comparative analysis and discrimination of 90 electrical tape adhesives. The objectives included the evaluation of the ability of individual techniques to discriminate samples and the assessment of the ability of the techniques combined to distinguish samples. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Stereomicroscopy, to assess adhesive colors of black, clear/colorless, and clear adhesives with brown tint, resulted in a discrimination of 53%. FTIR analysis yielded eight distinct groups with a discrimination of 67%. Py-GC/MS analysis resulted in 16 groups with a discrimination of 83%. These analyses confirmed and further subdivided the FTIR groups. SEM/EDS resulted in five separate groups at 17% discrimination, increasing the overall discrimination to above 85%.     

Differentiation of bullet type based on the analysis of gunshot residue using inductively coupled plasma mass spectrometry

Porcine tissue samples shot with two different types of bullets, jacketed and nonjacketed, were collected in the fresh state and throughout moderate decomposition. Wound samples were microwave-digested and analyzed using inductively coupled plasma mass spectrometry (ICP-MS) to detect all elements present at measurable levels in gunshot residue (GSR). Elements detected included antimony (Sb), barium (Ba), and lead (Pb), which are considered characteristic of GSR, as well as iron (Fe) and copper (Cu). These five elements were used to differentiate shot tissue and unshot tissue, as well as tissue shot by the two different bullet types, both in the fresh state and throughout moderate decomposition. The concentrations of Cu, Sb, and Pb were able to distinguish the two bullet types in fresh tissue samples at the 95% confidence level. Cu and Pb were able to differentiate the bullet types throughout moderate decomposition at the 99% confidence level.     

The Effects of Body Mass on Cremation Weight*

Abstract: Cremains have become increasingly frequent in forensic contexts, while higher body mass in the general population has simultaneously made cremation a more cost‐effective mortuary practice. This study analyzed the relationship between body mass and bone mass, as reflected through cremation weight. Antemortem data were recorded for samples used in the multi‐regional data set. Each was rendered through commercial crematoriums and reweighed postincineration. Pearson’s correlation demonstrates clear association between body mass and cremation weight (r = 0.56; p < 0.0001). However, multiple linear regression revealed sex and age variables also have a significant relationship (t = 7.198; t = ?2.5, respectively). Regressed in conjunction, body mass, sex, and age contribute approximately 67% of all variation observed in cremation weight (r = 0.668). Analysis of covariance indicates significant regional variation in body and cremation weight. Explanations include bone modification resulting from increased loading stress, as well as glucose intolerance and altered metabolic pathways related to obesity.     

Factors affecting the forensic examination of automotive lubricating oils

Lubricating oil comparisons impact a variety of forensic investigations, including cases where oil was transferred from a suspect vehicle to the crime scene or victim. In this study, high-temperature gas chromatography/mass spectrometry was used to examine the influence of oil mixtures and oil changes over time on the comparison of known and questioned lubricating oils. Varying concentrations of oil mixtures were prepared and showed the potential for identifying individual components. Motor oils from 18 automobiles monitored over a 2-month period did not demonstrate significant changes in the chromatographic data. Chemometric analysis of motor oil mass spectral data provided little information regarding differentiation of, or changes in, the samples. Power steering fluid (PSF) from a naturally occurring leak collected from several locations was consistent with the PSF in the automobile's reservoir, and the PSF composition did not change over time.     

离子交换柱法萃取血样中4种巴比妥类药物

目的建立血样中4种常见巴比妥类药物的固相萃取方法。方法采用Oasis MAX固相萃取柱对样品进行预处理,以2%氨水淋洗2,%甲酸-甲醇洗脱,GC/NPD定量检验,GC/MS定性检验。结果血样中4种常见巴比妥类药物平均萃取回收率达80%以上,以信噪比10/1计,最小定量限为1～2μg/mL,以信噪比3/1计,检出限为0.5～1μg/mL,在1～50μg/mL范围内,线性相关系数均在0.99以上。结论本文固相萃取方法检出限低,回收率高,选择性强,可应用于血样中4种常见巴比妥类药物的检测。     

Accidental death from hydromorphone ingestion

Abstract: A 15‐year‐old male orally consumed an unknown but fatal amount of sustained release hydromorphone. He was naïve to opioid use. No other drugs or alcohol were involved. The cause of death was acute aspiration‐related bronchopneumonia, secondary to hydromorphone ingestion; the manner of death was accidental. Hydromorphone and hydromorphone‐3‐glucuronide were quantified in postmortem fluids by tandem liquid chromatography–mass spectrometry. The hydromorphone concentrations in the peripheral blood, urine, and vitreous humor were 57, 4460, and 31 ng/mL, respectively. The hydromorphone‐3‐glucuronide concentrations in the corresponding three fluids were 459, 36,400, and 40 ng/mL. Hydromorphone‐3‐glucuronide accumulation probably did not contribute significantly to the opiate toxicity. The proposed minimum lethal hydromorphone blood concentration in the nontolerant user is in the vicinity of 60 ng/mL.     

Synthesis and identification of urinary metabolites of 4-iodo-2,5-dimethoxyphenethylamine

This article describes the synthesis and identification of urinary metabolites of 4-iodo-2,5-dimethoxyphenethylamine (2C-I), a new psychoactive drug. 2C-I hydrochloride was administered orally to male Sprague-Dawley rats, and the urinary extracts were analyzed by gas chromatography/mass spectrometry (GC/MS), then five putative 2C-I metabolites were synthesized in our laboratory. In the synthetic process of the 2C-I metabolites, iodination of the aromatic ring was successfully carried out using iodine and orthoperiodic acid as the iodination reagent, and selective debenzylation of aryl benzyl ether was accomplished by the acid hydrolysis method using trifluoroacetic acid and thioanisole. The synthesized metabolites were well separated and detected by GC/MS after valeryl derivatization. The results showed that 2C-I underwent O-demethylation, N-acetylation, and deamination, followed by oxidation to the corresponding carboxylic acid in rats. The data presented in this study will be very useful for the analysis of 2C-I and its metabolites in forensic samples.     

Sulfuric, hydrochloric, and nitric acid-catalyzed triacetone triperoxide (TATP) reaction mixtures: an aging study

The organic peroxide explosive triacetone triperoxide (TATP) is regularly encountered by law enforcement agents in various stages of its production. This study utilizes solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) to examine sulfuric acid-, hydrochloric acid-, and nitric acid-catalyzed TATP syntheses during the initial 24 h of these reactions at low temperatures (5-9°C). Additionally, aging of the reaction mixtures was examined at both low and ambient temperatures (19-21°C) for a further 9 days. For each experiment, TATP could be readily identified in the headspace above the reaction mixture 1 h subsequent to the combination of reagents; at 24 h, TATP and diacetone diperoxide (DADP) were prominent. TATP degraded more rapidly than DADP. Additionally, chlorinated acetones chloroacetone and 1,1,-dichloroacetone were identified in the headspace above the hydrochloric acid-catalyzed TATP reaction mixture. These were not present when the catalyst was sulfuric acid or nitric acid.     

论毛泽东领导思想

中国共产党成立90年来,带领中华民族不断从胜利走向胜利,取得了举世瞩目的成绩。这得益于党的领导集体在中国革命和社会主义事业建设实践中,始终坚持创造性地运用马克思列宁主义,走理论与实践相结合的正确道路。其中,毛泽东领导思想及其实践,为党的领导事业奠定了深厚的基础。文章深入研究了毛泽东的领导路线、领导职责、领导作风及领导方法,这对于提高新形势下党的执政能力和领导水平具有重要指导和借鉴作用。     

Differentiation of blue ballpoint pen inks by laser desorption ionization mass spectrometry and high-performance thin-layer chromatography

The differentiation of inks on a questioned document can highlight a fraudulent insertion and is usually carried out by optical comparison and thin-layer chromatography (TLC). Laser desorption ionization mass spectrometry (LDI-MS) may also be used for the analysis of dyes from ink. This analytical technique was compared with a standard method of high-performance TLC (HPTLC) according to their capacity to differentiate blue ballpoint inks. Ink entries on paper from 31 blue ballpoint pens have been analyzed and their dye ink formulations compared. The pens were classified into 26 classes by LDI-MS against 18 for HPTLC. LDI-MS proved to be a more powerful method for differentiating ink formulations because it provides information about dye structures (molecular weights) and relative quantification of dye classes (peak areas). Sample preparation was minimal and analysis time was short in contrast to the more complex extraction, application, and development steps of the HPTLC method. However, only basic dyes and pigments were identified using positive mode LDI-MS, while HPTLC did yield additional information about acid dyes.