Two fatal cases of selenium toxicity

Two patients, a 36-year-old female and a 36-year-old male, separately experienced new onset nausea, vomiting, diarrhea, abdominal pain, muscle weakness and pallor. Over a period of 14-16 h these symptoms continue and progress to include hypotension refractory to therapy, pulmonary edema and cardiovascular collapse. Autopsies show hemorrhagic pulmonary edema, splenomegaly and lack of anatomical cause for sudden death. Postmortem analysis, in one case post-embalming and exhumation, revealed elevated selenium concentrations and a determination of the cause of death. These two cases present several important features associated with selenium toxicity, two of which are previously unreported: (1) selenium as a potential homicidal agent, (2) the toxidrome and time frame of selenium toxicity, (3) selenium determination in exhumed, embalmed tissues, (4) postmortem urinary selenium concentration, and (5) decrease in tissue concentrations over time.     

鱼塘水中微量铜的原子吸收检验

采用原子吸收检验测定因投放铜盐导致鱼大批死亡的鱼塘水中的微量铜以空白鱼塘水为对照,铜标准液做标准曲线,方法简单,结果准确可靠,是该类案件检测的较好方法之一.     

氢化物原子荧光法测定人发中砷含量的不确定度评定

目的评定氢化物原子荧光法测定人发中砷含量的不确定度。方法以人发标准样品为分析对象,依据化学分析中不确定度的评估指南等指导性文件,分析测定过程中砷含量测定值（C）、样品处理后的总体积（V）、样品称量值（m）以及重复测量（rep）等多个不确定度分量,计算检测结果的合成标准不确定度和扩展不确定度。结果本文方法测定人发中砷含量的不确定度评定结果为：人发样品中砷的含量为（0.57±0.06）mg/kg,置信概率（p）=95%,自由度（υeff）=4。结论本文方法测量不确定度的主要来源是重复性和校准曲线,测定结果在标准物质给出的含量范围之内。     

The discrimination of automotive clear coats by pyrolysis-gas chromatography/mass spectrometry and comparison of samples by a chromatogram library software

Identification particles used for the purpose of the post-blast identification of explosives have a coding system based on the combination of metal oxides and their various concentrations. These materials are composed of the polymeric matrix, iron powder (ferromagnetic properties), UV light active dyestuff and various metal oxides in a various ratios. A suitable analytical method has to be used for an accurate characterization of these metal components in the particles in order to find the required information, i.e. to determine the place and the year of production and as the case may be, also the production batch of misused explosives. In this work, the method of microwave digestion and flame atomic absorption spectrometry (F-AAS) was developed for an accurate determination of Zn, Mg, Cu and Pb in a few novel types of identification particles and applied to their characterization. When using specific sample treatment (digestion with a mixture of nitric acid with hydrochloric or hydrofluoric acid), the 3 sigma limits of detection (LODs) for the determination of Zn, Mg, Cu and Pb in 5mg original samples were 1.9, 0.2, 1.3 and 2.4 mg g(-1), respectively. The signal suppression due to the presence of HNO3+HCl or HNO3+HF was observed for Zn; therefore, the calibration solutions had to be prepared exactly with the same acids as those used for the sample mineralization. The determination of Mg, Cu and Pb was free of interferences; hence a simple calibration curve method could be adopted for attaining accurate results. The accuracy was checked by comparison of the results with those obtained by means of independent inductively coupled plasma optical emission spectrometry (ICP-OES). Good precision values, as relative standard deviation, in the range of 1-5% were obtained. A total number of 71 samples was analysed and classified by multivariate methods to prove the suitability of the procedure proposed for the purpose of the identification of explosives.     

Concentrations of mustard gas [bis(2-chloroethyl)sulfide] in the tissues of a victim of a vesicant exposure

An Iranian soldier died at a toxicological intensive care unit at Munich seven days after a vesicant exposure. At the autopsy the typical symptoms of mustard gas intoxication were found. The vesicant was detected qualitatively by gas chromatography-mass spectrometry (GC-MS) in the abdominal fat and quantified in the tissues and in the body fluids by the following method: (1) extraction by dichloromethane, (2) cleanup of the extracts by thin-layer chromatography (TLC) on silica plates, (3) extractive derivatization with gold-chloride, and (4) quantitative determination by electrothermal atomic absorption spectrometry (ET-AAS). The equal extracts, after heating, served for blanks. The following concentrations were found (milligrams of mustard gas/kilograms of tissue wet weight): brain 10.7, cerebrospinal fluid 1.9, liver 2.4, kidney 5.6; spleen 1.5, lung 0.8, muscle 3.9, fat 15.1, skin 8.4, skin with subcutaneous fatty tissue 11.8, liquid from a skin blister: below detection limit, blood 1.1, and urine: below detection limit.     

Postmortem serum selenium concentrations and their possible etiological role in Sudden Infant Death (SID)

The importance of selenium (Se) deficiency in the pathogenesis of human diseases such as Keshan Disease has been extensively studied. It is possible that low Se-levels could cause immunosuppression and be an etiological factor in Sudden Infant Death (SID). We investigated 50 serum samples (40 SID and 10 non-SID victims) by atomic absorption spectrometry. The results show that there is no evidence of a serum selenium deficiency in SID-victims in the region of Aachen. A relationship between selenium concentration and the infant immune system still remains speculative and 21 samples even showed increased serum levels. It could be necessary to define a ‘local’ normal range by examining a greater number of healthy infants.     

原子荧光光谱法在金属毒物检验中的应用

原子荧光光谱法是近年来发展起来的一类分析方法。本文综述了原子荧光光谱法的基本原理、操作方法以及该技术在金属检验中的应用。     

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.     

生物组织中甲胺磷及其异构体的串联质谱法分析

目的建立可用于生物体内甲胺磷及其异构体O,O二甲基氨基硫代磷酸酯检验的高灵敏度方法。方法应用串联质谱法(GCMS/MS),对生物样品中的甲胺磷及其异构体进行检验研究。结果选择质荷比为141的离子为母离子,击发电压为0.8V时,甲胺磷及其异构体二次电离碎片适中,质谱谱图清晰。50%甲胺磷乳油进样量为0.1ng时,甲胺磷及O,O二甲基氨基硫代磷酸酯峰的信噪比分别为436、773。经实验,甲胺磷检测限为20pg。结论所拟方法能有效提高甲胺磷的检测灵敏度。     

The analysis of casework sized alloy fragments by inductively coupled plasma-optical emission spectrometry (ICP-OES) using discrete nebulisation

A discrete nebulisation technique has been developed for the multi-element analysis of 100-μl solution droplets by inductively coupled plasma-optical emission spectrometry (ICP-OES). The technique increases analytical speed and uses very small solution volumes with only a slight degradation in detection limits when compared to continuous solution introduction.To evaluate its suitability in casework, small alloy fragments were produced by cutting with a hacksaw, sample division and filing. The analysis of fragments from two different brasses indicated that quantitative data could be obtained from fragments as small as 10 μg. The accurate determination of lead, a non-homogeneous constituent of leaded brasses, required sample sizes an order of magnitude greater. Analysis of an alloy of fine grain structure (copper-nickel) demonstrated that quantitative data could be obtained from samples weighing a few micrograms or less.     

液相色谱-串联质谱法分析生物检材中的河豚毒素

目的建立血液、尿液以及肝中河豚毒素(tetrodotoxin,TTX)的液相色谱-串联质谱分析方法,并进行方法学验证。方法血液、尿液和肝用1%乙酸甲醇溶液去蛋白后,上清液用固相萃取法净化,LC-MS/MS检测。结果血液、尿液和肝中TTX检出限分别为2ng/mL、2ng/mL和4ng/g。血液和尿液在4～100ng/mL、肝在5～100ng/g的范围内线性关系良好,相关系数r≥0.9973;日内精密度和日间精密度均在12.80%以内;回收率大于47.2%。结论所建方法高效、灵敏、准确,可以为河豚毒素中毒的法医学鉴定、临床诊治以及食品安全的监控提供技术保障。     

Improved gas chromatography-negative ion chemical ionization tandem mass spectrometric method for determination of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid in hair using mechanical pulverization and bead-assisted liquid-liquid extraction

A gas chromatography-negative ion chemical ionization tandem mass spectrometric (GC-NCI-MS/MS) method was developed and validated for the determination of 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in human hair. After decontamination, hair samples were weighed (25mg), mechanically pulverized with a bead mill, and incubated in 0.7 mL of 1.0M sodium hydroxide at 95 °C for 30 min. Bead-assisted liquid-liquid extraction was performed with n-hexane:ethyl acetate (9:1, v/v), a method developed in our laboratory. The extract was evaporated to dryness, derivatized with pentafluoropropanol and pentafluoropropionic anhydride, and analyzed by GC-MS/MS in the negative ion chemical ionization mode using methane as the reagent gas. The linear ranges were 0.05-10.0 pg/mg for THC-COOH with the coefficient of determination (r(2) = 0.9976). The intra-day and inter-day precisions were within 1.7 and 13.8%, respectively. The intra-day and inter-day accuracies were -4.8 to 10.0% and -3.9 to 3.8%, respectively. The limit of detection and quantification were 0.015 and 0.05 pg/mg, respectively. The recoveries were in the range of 79.4-87.1%. The results indicate that the proposed method is simple, rapid, accurate, and precise for determination of THC-COOH in hair. The method identified THC-COOH in hair specimens from suspected marijuana abusers.     

Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial

A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.     

Development of a specific fragmentation pattern-based quadrupole-Orbitrap™ mass spectrometry method to screen drugs in illicit products

Over the past decade, illicit drugs have been founded in marketed products, which pose a risk to public health. In particular, newly designed analogues synthesized by chemical modification of parent compounds to avoid detection by authorities are frequently detected worldwide. Although many analytical methods for determination of drugs have been reported, analytical methods using high-resolution mass spectrometry, which has the advantage of rapid screening and accurate identification of new substances, are necessary to control illicit drugs in marketed products. In this study, a rapid analytical method using an Orbitrap™ mass spectrometer for identification of illicit drugs in marketed products was developed. The 32 drugs were classified as benzodiazepine-, synthetic cannabinoid-, amphetamine- and benzylpiperazine-type drugs according to their chemical structures, and from their fragmentation patterns in tandem mass spectrometry spectra of an established method. The method validation gave a limit of detection of 0.06–5.30 ng/mL and a limit of quantification of 0.18–16.50 ng/mL, high linearity (R² > 0.994) and mean recoveries of spiked matrix-blank samples ranging from 83.7% to 117.1%. Approximately 71% of 21 samples collected over 3 years were found to individually contain one of four types of benzodiazepines or two different synthetic cannabinoids. In one case, levels as high as 827.2 mg/g were measured suggesting adulteration at high levels, which suggests that potential illicit products containing drugs should be regularly screened to protect public health.     

HPLC／MS检测生物样品中的丁丙诺啡

目的建立了生物样品中丁丙诺啡的高效液相色谱-电喷雾串联质谱检测方法。方法样品经固相萃取提取净化、反相液相色谱分离后进行质谱检测，根据保留时间及特征离子进行定性分析，以母离子m／z468进行定量分析。结果在10-500ng／ml（ng／g）范围内峰面积与质量浓度的线性关系良好（r^2〉0．993）。在50、100、500ng／ml（ng／g）3个添加水平，尿、血、肝中丁丙诺啡的平均回收率为74％～94％，日内测定结果的相对标准偏差小于8％，日间测定结果的相对标准偏差小于10％。结论该方法简单、灵敏，特异性强，适用于生物样品中丁丙诺啡的分析检验。     

Acute selenium poisoning: suicide by ingestion

Selenium is a ubiquitous element in the environment essential to the human diet and widely utilized in industrial processes. Fatal human selenium intoxication is rare. The authors report a case in which investigators recovered a bottle of gun-bluing agent beside a 24-year-old man. He exhibited signs and symptoms typical of acute selenium intoxication presenting with nausea and vomiting, followed by pulmonary edema and rapid cardiovascular collapse approximately 3 to 4 h after ingestion. Classic electrocardiographic (EKG) changes, which have been reported to occur in acute selenium intoxication, included sinus tachycardia with ST wave alteration. Toxicological results confirmed elevated blood and tissue concentrations. The cause of death was ascribed to acute selenium intoxication, which ensued rapidly after oral consumption. The manner of death was suicide. This case report, which presents an overview of acute and chronic selenium poisoning, underscores the value of thorough toxicologic analyses of tissue and body fluids in humans.     

Determination and validation of tetrodotoxin in human whole blood using hydrophilic interaction liquid chromatography-tandem mass spectroscopy and its application

A sensitive analytical method was developed for the quantitative determination of tetrodotoxin (TTX), a powerful sodium channel blocker, in human postmortem whole blood. The sample mixture was cleaned up using cation exchange SPE catridge after protein precipitation by methanol and then separated on a PC-HILIC (phosphorylcholine hydrophilic interaction liquid chromatography) column (150 mm × 2.0mm i.d., 5 μm) using a isocratic elution of 1% acetic acid and acetonitrile. The identification of TTX was performed on tandem mass spectrometry with electrospray ionization interface in positive ion mode. The retention time of voglibose (internal standard) and TTX was 5.1 and 6.0 min, respectively. TTX and internal standard (voglibose) were monitored and quantitated using the ion transitions: the respective precursor to product ion combinations, m/z 320/302 for TTX and m/z 268/92 for voglibose in the multiple reaction monitoring (MRM) mode. The recovery of TTX and voglibose was 61.4% and 62.8%, respectively and the good accuracy (97.7-103.9%), linearity (2-1200 ng/mL) and reproducibility were shown in this method. The limit of detection and limit of quantification were 0.32 ng/mL and 1.08 ng/mL, respectively. This method was applied in the case of three fishermen who were poisoned (including one death) by unknown fish on their boat in October 2010. In this case, the levels of TTX were 27.2, 30.0 and 29.7 ng/mL in heart blood, peripheral blood and serum of a victim, were 3.1 and 12.1 ng/mL in peripheral blood and 3.9 and 12.8 ng/mL in serum of two survivors, respectively.     

紫外分光光度法和二阶导数光谱法测定水样中的敌草快

目的建立测定水样中的敌草快的分析方法。方法采用紫外分光光度法和二阶导数光谱法测定水样中的敌草快。结果紫外分光光度法直接测定水样中的敌草快,在0.1~50μg/mL范围内线性关系良好,日内,日间精密度均小于2.6%。二阶导数光谱法在0.1~10μg/mL线性关系良好,日内、日间精密度均小于1.29%。结论该两种方法快速、简单、灵敏,适用于环境监测工作。     

Basic forensic identification of artificial leather for hit-and-run cases

Single fibers retrieved from a victim's garments and adhered to the suspect's automobile have frequently been used to prove the relationship between victim and suspect's automobile. Identification method for single fiber discrimination has already been conducted. But, a case was encountered requiring discrimination of artificial leather fragments retrieved from the victim's bag and fused fibers from the bumper of the suspect's automobile. In this report, basic studies were conducted on identification of artificial leathers and single fibers from leather materials. Fiber morphology was observed using scanning electron microscopy (SEM), color of these leather sheets was evaluated by microspectrophotometry (MSP), the leather components were measured by infrared micro spectrometry (micro-FT-IR) and the inorganic contents were ascertained by micro-X-ray fluorescence spectrometry (micro-XRF). These two methods contribute to other analytical methods too, in the case of utilized single fiber analytical methods. The combination of these techniques showed high potential of discrimination ability in forensic examinations of these artificial leather samples. In regard with smooth surface artificial leather sheet samples, a total of 182 sheets were obtained, including 177 colored sheets directly from 10 of 24 manufacturers in Japan, and five of them were purchased at retail circulation products. Nine samples of suede-like artificial leather were obtained, 6 of them were supplied from 2 manufacturers and 3 sheets were purchased as retailing product. Single fibers from the smooth surface artificial leather sheets showed characteristic for surface markings, and XRF could effectively discriminate between these sheets. The combination of results of micro-FT-IR, color evaluation by MSP and the contained inorganic elements by XRF enabled to discriminate about 92% of 15,576 pairs comparison. Five smooth surface samples form retailing products were discriminated by their chemical composition into four categories, and in addition color information to this result, they were clearly distinguished. Suede-like artificial leather sheets showed characteristic extra-fine fibers on their surface by the observation of SEM imaging, providing high discriminating ability, in regard with suede-like artificial leather sheets were divided into three categories by micro-FT-IR, and the combination of these results and color evaluation information, it was possible to discriminate all the nine suede-like artificial leather sheets examined.     

液相色谱-串联质谱法测定血液和尿液中秋水仙碱

目的建立检测血液和尿液中秋水仙碱的液相色谱-串联质谱法。方法0.5mL血液或尿液以丁丙诺啡为内标,经pH9.2硼酸盐缓冲溶液碱化后,用乙酸乙酯进行提取,在ZORBAX SB-C18液相柱(150mm×2.1mm×5μm)上以V(甲醇)∶V(20mmol/L乙酸铵和0.1%甲酸缓冲溶液)=80∶20为流动相,流速为0.2mL/min,采用电喷雾正离子模式离子化、多反应监测模式检测秋水仙碱,内标法定量。结果血液、尿液中秋水仙碱与内标丁丙诺啡色谱分离良好,秋水仙碱在0.1~50 ng/mL内均具有良好的线性,相关系数>0.9990,最低检出限为0.05ng/mL,方法回收率为94%~116%,日内与日间精密度(RSD)均小于8.5%。结论所建LC-MS-MS方法灵敏度高、操作简便、快速、准确,适用于血液及尿液等生物检材中痕量秋水仙碱成分的检测。