A novel method for cyanide quantification in human whole blood using ion chromatography with amperometric detection and its application to cyanide intoxication cases

Cyanide is a highly toxic agent that has been frequently used for suicide in South Korea. It is also used in various industrial fields, such as metal plating, in which many accidental cyanide intoxications have occurred. To overcome the disadvantages of conventional cyanide analysis methods, a simple and fast method for the analysis of cyanide in whole blood using ion chromatography (IC) with amperometric detection was developed in this study. Whole blood samples were deproteinized, diluted, and analyzed using an IC–amperometric detection system. The limits of detection and quantitation were 0.1 and 0.2 mg/L, respectively. The method showed good linearity in the range of 0.2 to 50 mg/L with R² > 0.99. The intra- and inter-assay precision and accuracy values were <10%. The established method was successfully applied to analyze whole blood samples from three cyanide intoxication cases.     

IgE死后生化学检测的研究现状及应用展望

过敏性休克导致死亡的案例在法医学实践中常有发生,然而由于缺少特异的病理形态学指征,导致过敏性休克死亡的法医学鉴定面临一定的困难。IgE作为介导I型超敏反应的关键介质,其死后生化学检测对过敏性休克死亡案例的法医学鉴定具有辅助作用。但在实际应用中,血液等检材常受溶血等死后变化因素影响,尤其我国尸体保存以冷冻为主,溶血程度更加严重,对IgE等生化学指标的检测造成极大干扰。本文就目前IgE死后生化学检测的研究现状、生物学检材的选取及检测方法进行综述,并对现实应用中所面临的问题进行探讨。     

Volatile Organic Compounds,Spectral Characterization and Morphology of Ammonium Nitrate Fuel Oil (ANFO) Samples

Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO.     

病毒性出血败血症病毒实时荧光RT-RPA恒温检测方法的建立

为建立一种简单、快速的病毒性出血败血症病毒(VHSV)检测方法,本研究通过比较分析VHSV N基因的保守序列,设计了多对引物和一条探针。经过筛选优化,建立了实时荧光RT-RPA检测方法。该方法在39℃恒温反应20 min即可快速、特异性地检测出VHSV,与其他水生动物病毒不发生交叉反应,该方法检测限为1.83×10^3PFU/mL,利用本研究方法对30份鲑鳟鱼临床样品以及9份鱼类疫病病原样品进行检测,检测结果与荧光定量PCR方法结果一致。上述结果表明,本研究建立的检测方法操作简单,反应灵敏,结果可靠,仪器依赖性低,适用于现场对VHSV快速检测。     

基于X-射线衍射法检测甲基苯丙胺晶体并推断来源

目的采用X-射线衍射法(XRD)建立一种快速检测甲基苯丙胺晶体并推断其来源的方法。方法对18起案件中的53份甲基苯丙胺样本进行XRD检验。结果通过分析主要特征峰强度比例,可以得到毒品的定性分析结果,以及样本的晶型取向信息;通过分析XRD谱图中毒品的特征峰半峰宽信息可以得到毒品的结晶度;对样本中明显的杂质峰进行比对,即可得到毒品来源信息参考。结论该方法简便快捷、无损样本、无污染,能够快速、准确、高效地分析结晶状毒品,为确定制贩毒集团上下线及涉毒案件串并案提供佐证。     

Evaluation of canine training aids containment for homemade explosive and components by headspace analysis and canine testing

While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel–oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material.     

Forensic integrity verification of video recordings based on MTS files

Digital video is used in criminal trials as evidence with legal responsibility because video content vividly depicts events occurring at a crime scene. However, using sophisticated video editing software, assailants can easily manipulate visible clues for their own benefit. Therefore, the integrity of digital video files acquired or submitted as evidence must be ensured. Forensic analysis of digital video is key to ensuring the integrity of links with individual cameras. In this study, we analyzed whether it is possible to ensure the integrity of MTS video files. Herein, we propose a method to verify the integrity of MTS files encoded by advanced video coding high definition (AVCHD), which is frequently used for video recording. To verify MTS file integrity, we propose five features. Codec information, picture timing, and camera manufacture/model are modified AVI and MP4-like format video verification features. Group of pictures and Universally Unique Identifier patterns were specifically developed for MTS streams. We analyzed the features of 44 standard files recorded using all recording options of seven cameras. We checked whether integrity can be validated on unmanipulated videos recorded in various environments. In addition, we considered whether manipulated MTS files edited in video editing software could be validated. Experimental results show that all unmanipulated and manipulated MTS files with known recording devices were discriminated only when all five features were checked. These results show that the proposed method verifies the integrity of MTS files, strengthening the validity of MTS file-based evidence in trials.     

2,4,6-Tri(2′-pyridyl)-1,3,5-triazine for determination of iron(II), Iron(III), and total iron contents on human palms

When iron-based tools, such as knives or guns, are held, traces of iron can transfer to the skin. However, no previous studies have been published regarding the effect of the elapsed contact time on the transfer of iron species with different valences to the palm. Compared with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (PDT), 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) was found to exhibit a higher sensitivity to iron(II) spectrophotometrically. This work employed 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) and UV spectrophotometry to determine the amounts of iron(II), iron(III), and total iron transferred to human palms from iron tools. It was found that the palmar moisture level was an important factor in determining the amounts of total iron, including iron(II), transferred to the palm. For identical contact times, the amounts of total iron transferred to the palm was proportional to the palmar moisture, and the difference between the maximum and minimum amounts was 12 μg per hand. However, the amounts of iron(II) transferred to the palm gradually decreased over time for low palmar moisture levels, but steadily increased over time for high palmar moisture levels. Additionally, for average levels of palm moisture, the amounts of iron(II) and iron(III) transferred to the palm gradually decreased and increased, respectively, with longer contact times. Notably, this research could serve as a theoretical basis and guide for the detection of trace iron species with different valences on human palms for criminal investigations.     

Stage model for female criminals: business school students’ perceptions of white-collar offenders

We know that half of the population in Norway is female, and we know that females represent 6% of the white-collar crime prison population. In the stage model overview, we derive percentages from the literature into the gender model to explain stepwise reduction from 50% to 6%. In our empirical research, we asked two groups of business school students to come up with their own estimates for the stages in the model for female criminals. While estimates from executive students resulted in 3% women in prison, bachelor students’ estimates resulted in 10% women in prison. The most obvious discrepancy between the research literature and our two survey groups is related to relative convictions. Based on the literature, we suggested that female defendants receive more serious convictions because they may perceive and feel more guilt for a crime, for example in terms of regret, shame and depression. Thus women may have a tendency to confess more easily. Both executive students and bachelor students disagree with this estimate of 140%, as they suggest 62% and 69% respectively. One reason for their suggestion of less serious convictions for female white-collar criminals – sometimes labelled pink-collar criminals – might be that family situation and other elements are taken into account before a verdict is passed on a woman. Another substantial discrepancy is related to detection risk. The literature suggests a low detection risk for women, but may be not as low as we estimated at 30%. Both executive and bachelor students believe that the gender difference in detection likelihood is not that formidable, as they suggest 75% and 65% respectively.     

基于上转换发光技术的尿液中吗啡及甲基苯丙胺快速定量检测方法研究

目的利用上转换发光免疫层析技术(UPT-LF)建立一种尿液中吗啡(MOP)及甲基苯丙胺(MET)快速定量检测方法并对其进行系统评价。方法以上转换发光纳米颗粒(UCP-NPs)作为生物示踪物,竞争模式免疫层析作为检测平台,建立可对尿液中MOP及MET进行定量检测的UPT-LF,即MOP-UPT-LF、MET-UPT-LF。以MOP-UPT-LF为代表,评价UPT-LF对痕量毒品检测极限,通过系列浓度标准品测定,评价定量检测能力。根据常规检测阈值,调整MOP-UPT-LF及MET-UPT-LF检测敏感性及线性范围,并评价其定量检测能力。以LC-MS、GC-MS分别作为MOP、MET检测的金标准,以胶体金免疫层析作为对照,对执法现场收集尿样进行检测,确定UPT-LF定性检测性能。对系列浓度MOP模拟阳性样本同时进行LC-MS及MOP-UPT-LF定量检测,对系列浓度MET模拟阳性样本同时进行GC-MS及MET-UPT-LF定量检测,评价UPT-LF定量检测性能。结果在痕量检测条件下,MOP-UPT-LF敏感性可达1ng/m L,线性范围为1~5000ng/m L(r=-0.98172,P<0.0005)。在常规检测条件下,MOP-UPT-LF敏感性为50ng/m L,线性范围调整为50~3000ng/m L(r=-0.98464,P<0.0005);MET-UPT-LF敏感性为100ng/m L,线性范围为100~5000ng/m L(r=-0.99964,P<0.0005)。就定性检测而言,MOP-UPT-LF及MET-UPT-LF均较优,灵敏度及特异度均为100%,与胶体金结果一致。就定量检测而言MOP-UPT-LF及MET-UPT-LF与定量确证方法LC-MS及GC-MS无显著差异。结论本研究建立MOP-UPT-LF、MET-UPT-LF方法,在满足快筛试剂快速简便的基础上,进一步实现了现场快速定量检测,为尿液中毒品的现场快速定量检测提供了技术保障。