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.     

顶空气相色谱内标法测定人血中乙醇含量的不确定度评定

目的建立顶空气相色谱内标法测定人血中乙醇含量的不确定度评定的方法。方法结合顸空法乙醇含量测定的全部过程,假设传播系数为1,则对产生不确定度的各分量因子进行分析计算与合成。结果不确定度因素的来源主要包含样品检测时产生的误差值、检测仪器的精密度、使用标准物质的标示值的不确定度和使用的量器、容量器皿等的不确定度。结论本评定方法得出检测的最大误差来自于两个平行样品检测时所产生的误差值。     

全二维气相色谱在刑事技术中的应用

综述了近年来发展起来的全二维气相色谱(GCхGC)技术正交分离系统原理及其特点以及在刑事技术中应用的发展前景。     

Stable carbon and nitrogen isotope ratios of sodium and potassium cyanide as a forensic signature

Sodium and potassium cyanide are highly toxic, produced in large amounts by the chemical industry, and linked to numerous high-profile crimes. The U.S. Centers for Disease Control and Prevention has identified cyanide as one of the most probable agents to be used in a chemical terrorism event. We investigated whether stable C and N isotopic content of sodium and potassium cyanide could serve as a forensic signature for sample matching, using a collection of 65 cyanide samples. Upon analysis, a few of the cyanide samples displayed nonhomogeneous isotopic content associated with degradation to a carbonate salt and loss of hydrogen cyanide. Most samples had highly reproducible isotope content. Of the 65 cyanide samples, >95% could be properly matched based on C and N isotope ratios, with a false match rate <3%. These results suggest that stable C and N isotope ratios are a useful forensic signature for matching cyanide samples.     

HS-SPME-GC/MS法检测尿液及毛发中苯丙胺类毒品

目的采用顶空固相微萃取（HS-SPME）、GC/MS分析方法,对生物样品中苯丙胺（AM）、甲基苯丙胺（MAM）、3,4-亚甲二氧基苯丙胺（MDA）和3,4-亚甲二氧基甲基苯丙胺（MDMA）4种苯丙胺类毒品进行定性定量分析。方法在碱性和饱和盐处理状态下,采用100μm聚二甲基硅氧烷（PDMS）萃取纤维,于顶空瓶中进行生物样品AM、MAM、MDA、MDMA 4种毒品萃取,以2-甲基苯乙胺为内标,经气-质联用选择离子检测（GC/MS/SIM）模式进行定性定量分析。对HS-SPME条件优化,对方法的精密度、准确度和检出限进行测定。结果 AM、MAM、MDA、MDMA 4种毒品尿液中的最低检出限为5ng/mL,毛发中的最低检出限为0.5ng/mg。尿液中线性关系范围为0.05μg/mL~5μg/mL,r〉0.991,回收率为82%~108%,RSD为2.6%~6.1%（n=5）;毛发中线性关系范围为5ng/mg~500ng/mg,r〉0.992,回收率为80%~113%,RSD（%）为1.4%~6.8%（n=5）。结论 HS-SPME-GC/MS各项定量参数符合分析要求。该方法简单、灵活、经济、快速、无溶剂,适用于生物检材中该类毒品的分析。     

固相萃取-气相色谱法提取全血中的外源性褪黑素

目的建立血样中褪黑素的固相萃取方法。方法采用OasisHLB固相萃取柱提取,GC/NPD定量检验,GC/MS定性检验。结果血样中褪黑素平均萃取回收率达80%以上,最低检出限0.02μg/mL,线性良好,相关系数R2=0.9978。结论该方法操作简便快速,提取回收率高,重现性好,提取物干净,可用于实际案件当中。     

腐败血液中乙醇的顶空气相色谱分析

目的分析血液腐败后产生的乙醇及其他物质并探讨腐败血液中乙醇的检测及计算方法。方法以正常人空白血液制作腐败血样,采用1,4-二氧六环为内标物,通过顶空气相色谱进行定性及定量分析。结果血中乙醇在0.0625～1mg/mL范围内线性关系良好（r^2=0.9996）,各质量浓度组的变异系数（CV%）〈2%,血中乙醇的最低检出限为1μg/mL（S/N≥3）。腐败血样所产生乙醇与正丙醇的比例大致为25：1。结论检验方法简便、准确。为法医毒化检验相关工作提供了依据。     

大鼠血液、尿液中阿米替林的气相色谱快速分析

目的建专：m液及尿液中阿米替林（AMTL）的气相色谱分析方法,、方法以正常大鼠m液及尿液为空F1样奉,分别添加AMTI-标准品和内标SKF525A。实验大鼠以AMTL2倍LD50灌胃,致大鼠急性中毒后提取血液及尿液。用乙醚提取样本中AMTL,采用GC／FID法进行定量分析,并考察实验条件,结果采用该方法,血液及尿液中AMTL线性池用分别为5～150μg／mL（r=0．993）和5～150μg／mL（r=0．998）;最低检测限（S／N／〉3）均为1．0陆g／mL;口内、口间精密度均小于6％,同收率存95.5％～105．6％之间。结论该方法方操作便捷、捧确度高,适用=fAMTL临床治疗中血药浓度快速监测和法医毒物分析鉴定。     

Development and validation of a simple GC-MS method for the simultaneous determination of 11 anticholinesterase pesticides in blood--clinical and forensic toxicology applications

Anticholinesterase pesticides are widely used, and as a result they are involved in numerous acute and even fatal poisonings. The aim of this study was the development, optimization, and validation of a simple, rapid, specific, and sensitive gas chromatography-mass spectrometry method for the determination of 11 anticholinesterase pesticides (aldicarb, azinphos methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, methamidophos, methidathion, methomyl, and terbufos) in blood. Only 500 μL of blood was used, and the recoveries after liquid-liquid extraction (toluene/chloroform, 4:1, v/v) were more than 65.6%. The calibration curves were linear (R(2) ≥ 0.996). Limit of detections and limit of quantifications were found to be between 1.00-10.0 and 3.00-30.0 μg/L, respectively. Accuracy expressed as the %E(r) was found to be between -11.0 and 7.8%. Precision expressed as the percent relative standard deviation was found to be <9.4%. The developed method can be applied for the investigation of both forensic and clinical cases of accidental or suicidal poisoning with these pesticides.     

Fast gas chromatography of explosive compounds using a pulsed-discharge electron capture detector

The detection of a mixture of nine explosive compounds, including nitrate esters, nitroaromatics, and a nitramine in less than 140 sec is described. The new method employs a commercially available pulsed-discharge electron capture detector (PDECD) coupled with a microbore capillary gas chromatography (GC) column in a standard GC oven to achieve on-column detection limits between 5 and 72 fg for the nine explosives studied. The PDECD has the benefit that it uses a pulsed plasma to generate the standing electron current instead of a radioactive source. The fast separation time limits on-column degradation of the thermally labile compounds and decreases the peak widths, which results in larger peak intensities and a concomitant improvement in detection limits. The combination of short analysis time and low detection limits make this method a potential candidate for screening large numbers of samples that have been prepared using techniques such as liquid-liquid extraction or solid-phase microextraction.     

HPLC-DAD determination of mepivacaine in cerebrospinal fluid from a fatal case

A fatal case involving mepivacaine-induced epidural anesthesia is described. The pathological findings were typical of cardiac shock from ischemic origin. Cerebrospinal fluid (CSF) was obtained several hours after death and mepivacaine was identified by gas chromatography-mass spectrometry (GC-MS). Its concentration was determined by high performance liquid chromatography with diode array detection (HPLC-DAD). Extraction from CSF was performed by deproteinization with acetonitrile. The mepivacaine concentration in the sample was 264 microg/mL. Concentrations of mepivacaine in CSF following epidural anesthesia are not reported in literature to our knowledge. This is the first reported case of death in which the mepivacaine concentration in CSF has been determined.     

A New Approach for the Carbon Monoxide (CO) Exposure Diagnosis: Measurement of Total CO in Human Blood Versus Carboxyhemoglobin (HbCO)

The aim of the study is to present the application of a headspace–gas chromatography–mass spectrometry (HS‐GC‐MS) method for the determination of the carbon monoxide (CO) blood concentration and to compare it with carboxyhemoglobin (HbCO) saturation. In postmortem cases, the HbCO measured by spectrophotometry frequently leads to inaccurate results due to inadequate samples or analyses. The true role of CO intoxication in the death of a person could be misclassified. The estimation of HbCO from HS‐GC‐MS CO measurements provides helpful information by determining the total CO levels (CO linked to hemoglobin (HbCO) and CO dissociated from hemoglobin). The CO concentrations were converted in HbCO saturation levels to define cutoff blood CO values. CO limits were defined as less than 1 μmol/mL for living persons, less than 1.5 μmol/mL for dead persons without CO exposure, and greater than 3 μmol/mL for dead persons with clear CO poisoning.     

固相萃取/气相色谱法检测全血中的扎来普隆

目的建立全血中扎来普隆的固相萃取/气相色谱检测方法。方法采用Oasis HLB固相萃取柱,5%甲醇水淋洗,二氯甲烷洗脱,GC/NPD定量检验,GC/MS定性检验,并对检测条件进行考察。结果扎来普隆与血中杂质分离良好,平均萃取回收率达89%以上,最低检出限20ng/mL,50～2000ng/mL内线性良好,相关系数R2=0.9945,日内RSD为3.1%～4.2%,日间RSD 5.8%～6.7%。结论该方法操作简便快速,提取回收率高,重现性好,提取物杂质少,可用于实际案件的检验。     

Thiodicarb and methomyl tissue distribution in a fatal multiple compounds poisoning

Abstract:  Thiodicarb is a nonsystemic carbamate insecticide whose acetylcholinesterase activity is related to its main methomyl degradation product. A 40-year-old woman was found dead in her car. Empty packages of medicines and an open bottle of Larvin^® containing thiodicarb were found near her body. No signs of violence nor traumatic injuries were noticed upon autopsy, and police investigations strongly suggested a suicide. Systematic toxicological analysis performed on postmortem specimens revealed the presence of various sedatives, hypnotics, and antipsychotic drugs in blood, urine, and gastric content. Some of the compounds identified were determined at blood concentrations well above the known therapeutic concentrations: zolpidem (2.87 mg/L), bromazepam (2.39 mg/L), nordazepam (4.21 mg/L), and levopremazine (0.64 mg/L). Specific analysis of thiodicarb and of its methomyl metabolite was then performed on all fluids and tissues collected during autopsy by liquid chromatography ion trap tandem mass spectrometry (LC-MS-MS). The anticholinesterase capacity of blood, urine, and gastric content collected at autopsy was 83%, 82%, and 32%, respectively (normal value: 0%). The presence of thiodicarb in the bottle found near the body corroborates the hypothesis of an intake of that compound. Although thiodicarb was only detected in gastric content (24.3 mg/L), its methomyl metabolite was quantified in most postmortem tissues and fluids: gastric content (19.9 mg/L), peripheral blood (0.7 mg/L), urine (8.5 mg/L), bile (2.7 mg/L), liver (0.7 mg/kg), kidney (1.7 mg/kg), lung (1.5 mg/kg), brain (9.3 mg/kg), and heart (3.6 mg/kg).     

Headspace‐Gas Chromatographic‐Mass Spectrometric Analysis of South American Commercial Solvents and their Use in the Illicit Conversion of Cocaine Base to Cocaine Hydrochloride

This study presents data that establish the makeup of solvents utilized in illicit cocaine hydrochloride production, as determined via the identification of the occluded solvents in the crystal matrix of the final product. The occluded solvent ratios can differ dramatically from the ratios of the original processing solvents. Additionally, the presented data suggest the diversion of commercial solvents to illicit cocaine hydrochloride laboratories. Thirty‐five commercial solvents were obtained from five chemical manufacturing companies in South America. Each solvent was qualitatively and quantitatively analyzed using static headspace‐gas chromatography‐mass spectrometry (HS‐GC‐MS). After obtaining the chemical profile for each commercial solvent, solvents and/or solvent mixtures were prepared to be comparable in composition to several of the commercial products. Over 90 individual batches of cocaine hydrochloride were prepared from cocaine base using these solvents or solvent mixtures, which match those most commonly employed in clandestine laboratories. Additionally, a number of unique manufacturing by‐products produced from processing solvents were identified, and their significance is discussed.     

Age estimation by a dental method: a comparison of Lamendin's and Prince & Ubelaker's technique

Lamendin et al. (J Forensic Sci 1992;37:1373) developed a general technique to estimate age of adults at death using two dental features: periodontosis and translucency of the tooth root. Prince and Ubelaker (J Forensic Sci 2002;47:107) modified this method, creating a formula for each sex and for different ancestries, and obtained more precise age estimations. In the present study, the validity of each method was tested in 45 males and 34 females of Spanish Caucasian origin, and a novel formula, based on Prince and Ubelaker method, was specifically developed for a population of mixed racial origin (mestizo) from Colombia, and findings obtained were again compared with those yielded by Lamendin adult dental aging technique. The Prince and Ubelaker method proved more accurate than the Lamendin technique in the Spanish Caucasian population, and our Prince and Ubelaker-based formula was also more accurate than the Lamendin et al. In both populations, the Lamendin method showed a higher mean error in estimations of the age of youngest and oldest individuals. These findings confirm the need to create specific formulas for each human group in order to obtain more accurate age estimates.     

Sudden death in toddlers caused by influenza B infection: a report of two cases and a review of the literature

Sudden fatal cases of influenza B infection in a 4-year-old girl and a 2-year-old boy are presented. Both children complained of abdominal pain without respiratory, neurologic or cardiac symptoms; additionally the girl had vomiting within 2 days of death. Autopsy revealed histological changes in the respiratory system consistent with a viral infection. Influenza B infection was identified by immunohistochemistry in the girl and real-time polymerase chain reaction in the boy. Additional testing including cultures, toxicology, and screening for metabolic disorders were negative. These cases illustrate the usefulness of viral testing, especially for influenza, in the medical legal autopsy of children even when the classic respiratory symptoms of flu are lacking.     

Toxicology and characteristics of fatal oxycodone toxicity cases in New South Wales, Australia 1999-2008

All cases of fatal oxycodone toxicity presenting to the New South Wales Department of Forensic Medicine over the period January 1, 1999, to December 31, 2008, were retrieved. A total of 70 cases were identified. The mean age was 48.9 years, 58.6% were men, 21.4% were suicides, and in 30% oxycodone had not been prescribed to the decedent. Injecting drug users constituted 27.1% of cases, and oxycodone tablets were injected immediately prior to death by 21.4%. The mean blood oxycodone concentration was 0.40 mg/L (range 0.06-53.00 mg/L). In all cases, psychoactive substances other than oxycodone were also detected, most frequently hypnosedatives (68.6%), other opioids (54.3%), antidepressants (41.4%), and alcohol (32.9%). Preexisting systemic disease was common: cardiovascular (64.2%), pulmonary (49.3%), hepatic (66.7%), and renal (43.9%).     

离子色谱法检测全血中的亚硝酸盐及其代谢产物

目的建立全血中亚硝酸盐的离子色谱分析方法。方法将0.5mL全血和1mL水混合,用乙腈沉淀血液中的蛋白质后依次过C18柱、Ag柱和Na柱,用于去除其中的有机物和氯离子后进行离子色谱检测,并对蛋白沉淀溶剂、前处理柱等最佳实验条件进行考察。结果采用本文方法对空白添加全血进行检测,在色谱图上亚硝酸根离子及其氧化产物硝酸根离子的保留时间分别为10.02min、19.21min。选择乙腈作为蛋白沉淀剂,C18柱去除有机物,Ag柱去除氯离子,Na柱去除银离子。全血中亚硝酸根离子的检出限为0.05μg/mL,亚硝酸根和硝酸根的总回收率为95.9%~117.3%。结论本文方法简便,回收率好,灵敏度高,适用于中毒者血液中亚硝酸盐的检测。