Acute and sub-acute paraquat poisoning in a pack of foxhounds

A case of paraquat poisoning in a pack of foxhounds is reported. The incident provided a unique opportunity to compare residues levels of paraquat in dogs showing symptoms of acute and sub-acute poisoning. Paraquat was detected in the urine up to six days after exposure. A high performance liquid chromatography method for determining paraquat in tissue is described.     

大鼠百草枯中毒后体内的分布研究

目的建立生物检材中百草枯的超高效液相色谱-质谱联用检测方法,研究百草枯灌胃染毒致死的大鼠动物模型。方法大鼠以1/2 LD_(50)剂量灌胃染毒,分别于染毒后0.5h、2h、4h、8h、12h、24h、48h、72h处死解剖,采集心、肝、脾、肺、肾、脑、肌肉、膀胱和胃组织,UPLC-MS/MS法定量检测各组织中百草枯。结果试验中大鼠灌胃后,4h以内胃是主要分布器官,胃中含量最多,其他器官中含量相对较低。4h内除胃以外的脏器含量变化不大,4h后胃内百草枯含量有所下降,除胃以外的脏器含量均升高。各组织与脑组织比较具有显著性差异(P0.05)。结论百草枯在大鼠体内死后分布不均匀并且各组织含量随着时间变化有所改变。百草枯UPLC-MS/MS方法、口服染毒致死的动物模型、各组织分布规律可为甲百草枯中毒死亡案件提供检测依据。     

Homicidal Paraquat Poisoning

Paraquat poisoning usually results from suicide, occupational, or accidental exposure. Herein, we report a rare fatal case of homicidal paraquat poisoning. A 58‐year‐old man was poisoned by taking paraquat‐mixed medicine and wearing paraquat‐soaked underwear. In the absence of a history of paraquat exposure, the patient was misdiagnosed with pulmonary infection and scrotal dermatitis and died of respiratory failure 24 days after the initial exposure to paraquat. Ultra‐performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) was applied to detect and quantify paraquat in postmortem specimens. The concentration of paraquat in postmortem specimens from high to low is lung (0.49 μg/g), brain (0.32 μg/g), kidney (0.24 μg/g), liver (0.20 μg/g), cardiac blood (0.11 μg/mL), and stomach wall (<LOQ). Identification of homicidal paraquat poisoning is not easy for a clinician or a forensic pathologist, it is important to consider the possibility of paraquat poisoning when patients suffer from rapidly aggravating pneumonia of unknown origin.     

Determination of paraquat from formalin-fixed tissue

In this paper, a sulfuric acid digestion method and a clean-up technique by using cation exchange resin followed by XAD-2 resin has been developed for the determination of paraquat from formalin-fixed tissue at the submicrograms per gram level. Formalin-fixed tissue is dissolved by hot sulfuric acid, then paraquat is isolated and purified with cation exchange chromatography. The eluted paraquat forms an ion-pair with sodium dodecyl sulfate, it is then adsorbed on XAD-2 resin. Paraquat is eluted, extracted and reduced with solvent mixtures, NaCl solution and dithionite reagent, respectively. The calibration graphs of zero-order and second-derivative spectroscopy are linear in the range of 0.01-5.0 mg/kg. The relative standard deviation was less than 5% and the detection limit was 0.02 mg/kg based on 0.5-g samples. The sensitivity of the proposed method could be increased by using larger sample sizes. The method was precise and gave a quantitative recovery of paraquat spiked into formalin-fixed liver homogenates (78%). The proposed method has been satisfactorily applied to the determination of paraquat in the formalin-fixed tissues of suspected poisoned cases. It has been shown to be of great value in the field of forensic toxicology especially when formalin-fixed tissue only is available.     

HPLC法测定百草枯急性中毒大鼠的体内分布

目的 应用高效液相色谱法对口服百草枯急性中毒大鼠体内分布进行测定。方法以200mg／kg剂量百草枯给予Wister大鼠灌胃,4h后脱臼处死,解剖取脑、心、肝、脾、肺、肾、胃、盲肠、肌肉等组织,应用固相萃取法提取,液相色谱法测定各器官组织中百草枯含量。结果各组织经检验,均检出百草枯;组织间百草枯含量（μg／g）相差明显,其中最高为胃（231．47±129．10）,其次为盲肠（87．08±39．86）、肺（22．73±10．20）,最低为心（2．01±0．36）。结论百草枯口服给药后组织分布较为广泛,除胃、肠外各脏器中以肺浓度最高。     

Determination of paraquat in raw and formalin-fixed tissues by electron spin resonance (ESR) spectroscopy

ESR method was applied to determine paraquat levels in fresh and formalin-fixed tissues. Paraquat was converted to paraquat radical by adding sodium dithionite to tissue homogenates and detected by ESR. Paraquat levels of more than 0.2 micrograms/ml homogenate could be quantified with 0.1 ml of the homogenate. The use of manganese ions for standardization of paraquat signal enabled much more accurate ESR measurements because this ion was quite stable and its signal did not overlap that of paraquat. Even with tissues fixed in formalin, tissues paraquat levels were measureable after removing formalin from the tissue extract. This fact was verified by studying two cases; the tissues were kept in formalin for 1.5 years in case 1 and for 6.5 years in case 2. In both cases, the paraquat contents in tissues were 0.02-0.08 micrograms/g. In this way ESR is one of the most suitable methods in determining low levels of paraquat in tissues even after they were preserved in formalin for a long time.     

An unusual case of fatal accidental paraquat poisoning

Paraquat, a useful contact herbicide is now used in over 130 countries of the world, including Sri Lanka. The number of cases of accidental poisoning reported with paraquat is small, relative to instances of suicide. When a clear history is not available, accidental paraquat poisoning is sometimes difficult to diagnose. A 9-year-old boy was admitted to a peripheral hospital with a history of diarrhoea and vomiting. He later developed abdominal pain, subcutaneous emphysema and difficulty in breathing. Following transfer to a district hospital and then to a teaching hospital, poisoning with paraquat was suspected only on day 11 of the illness. On persistent questioning, on day 13 of the illness the child remembered that the day prior to the onset of illness, on his way from a shop, he felt thirsty and having found an empty bottle of Gramoxone (paraquat) on the wayside he used it to drink water from a water tank. The child died on day 17 and the histology of the lung showed typical changes of paraquat poisoning. This tragic episode emphasises the need for proper disposal of empty containers of all poisonous substances.     

Tissue distribution of paraquat and diquat after oral administration in rats

The differential distribution of paraquat and diquat in liver, kidney, lung, brain and heart has been studied after oral administration of the LD50 or LD50/2 to rats. Paraquat concentrations were highest in all organs at 24 hours; at this time concentrations in kidney and lung were 2 to 3 times higher than at 2 hours. In contrast, with the exception of kidney, tissue diquat concentrations were highest at 2 hours. There was severe lung damage at 24 hours after paraquat; diquat aid not produce severe lung lesions, but caused intestinal distention and diarrhea. These findings suggest that the difference in the toxicity of paraquat and diquat is related to their difference in tissue distribution and excretion.     

Determination of paraquat in tissue using ion-pair chromatography in conjunction with spectrophotometry

Homogenized tissue was deproteinized with sulfuric acid. Paraquat in the supernatant was quantificated directly with the dithionite reagent (step 1) or concentrated by the XAD-2 column chromatographic technique before paraquat determination (step 2). Tissue paraquat levels in the range of 0.01-75 mg/kg could be quantificated by second-derivative or zero-order spectroscopy using 2.5 g of tissues. The sensitivity could be increased tenfold by using 25 g of tissue samples. The coefficients of variation of within-run and day-to-day precisions of spiked paraquat in tissue homogenates were below 5% at concentrations of 10.0, 1.0 and 0.1 mg/kg, respectively. The recoveries of the spiked paraquat in tissues ranging from 0.1-10 mg/kg were 91% by step 1 and 74% by step 2. Using these simple methods, steps 1 and 2, the paraquat concentrations in the psoas muscle, liver, lung and kidneys of a swine dosed with 0.16 g/kg of paraquat were investigated. The results were in close agreement with those of the TCA deproteinization method followed by cation-resin column chromatography. The proposed method offers the advantages of simplicity, rapidity, reasonable sensitivity and a wide range of concentrations.     

离子对SPE—HPLC法检测生物检材中的百草枯

目的建立生物检材中百草枯的简便、快速、灵敏、可靠的高效液相色谱分析方法。方法生物检材酶解后,用以十二烷基三甲基溴化铵和十二烷基硫酸钠预处理过的C18固相柱萃取,HPLC/DAD进行分析。结果回收率81%～94%,检出限为1ng·mL-1,线性范围50ng·mL-1～1mg·mL-1,结论此方法适用于中毒生物检材中百草枯的检测。     

Determination of Herbicides Paraquat,Glyphosate, and Aminomethylphosphonic Acid in Marijuana Samples by Capillary Electrophoresis

In this work, two methods were developed to determine herbicides paraquat, glyphosate, and aminomethylphosphonic acid (AMPA) in marijuana samples by capillary electrophoresis. For paraquat analysis, sample was extracted with aqueous acetic acid solution and analyzed by capillary zone electrophoresis with direct UV detection. The running electrolyte was 50 mmol/L phosphate buffer (pH 2.50). For glyphosate and AMPA, indirect UV/VIS detection was used, as these substances do not present chromophoric groups. Samples were extracted with 5 mmol/L hydrochloric acid. The running electrolyte was 10 mmol/L gallic acid, 6 mmol/L TRIS, and 0.1 mmol/L CTAB (pH = 4.7). The methods presented good linearity, precision, accuracy, and recovery. Paraquat was detected in 12 samples (n = 130), ranging from 0.01 to 25.1 mg/g. Three samples were positive for glyphosate (0.15–0.75 mg/g), and one sample presented AMPA as well. Experimental studies are suggested to evaluate the risks of these concentrations to marijuana user.     

Detection of organophosphate poisoning in a putrefying body by analyzing arthropod larvae

Deaths as a result of organophosphate poisoning are usually detected by analysis of body fluids and tissues for the presence of the toxic agent. These procedures present particular difficulties when performed on remains in an advanced stage of decomposition. Malathion poisoning was suspected in a case in which the remains were in an advanced stage of decomposition and the presence of malathion was confirmed by analyses of gastric content and body fat. Two species of fly larvae, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart), were present on the remains. A sample of these larvae was analyzed for malathion content. A total of 574 micrograms of malathion was detected in 0.26 g of pooled larvae, or a level corresponding to 2050 micrograms/g of larvae. Presence of organophosphates in arthropod larvae has not been documented previously and the analysis of larvae from decomposing remains may prove a useful technique for detection of these toxicants in decomposing remains.     

Paraquat poisoning

A fatal case of paraquat poisoning is described. Postmortem concentration of paraquat in different tissues reveals that treatment in this case could not prevent lethal tissue accumulation. Although accumulation was more pronounced in renal tissue, lung toxicity caused death. The formation of enormous fecaliths and the appearance of hypercalcemia are reported. Both were most likely connected with Füllers earth therapy. In spite of the fact that the exact nature of the equilibrium between plasma levels and tissue accumulation of paraquat (static or dynamic) is not understood, aggressive treatment must be recommended, even after the distribution phase and despite likely "fatal" plasma levels.     

苯二氮卓类新精神活性物质去氯依替唑仑的定性检验方法研究

目的建立苯二氮卓类新精神活性物质去氯依替唑仑的气相色谱-质谱(GC-MS)和超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)定性检验方法。方法未知样品用甲醇和水提取,取上清液,采用GC-MS和UPLC-Q-TOF MS进行分析。结果经GC-MS检测,保留时间为17.73 min的未知组分的质谱碎片主要特征离子峰有m/z 279,308,239,252,225,77,126。经UPLC-Q-TOF MS检测,保留时间为4.781 min的未知组分的准分子离子峰为309.1173,碰撞诱导解离(CID)模式下二级质谱主要离子有m/z 280.0776,255.0952,240.0719,225.0604,206.0748。经缴获毒品分析科学工作组(Scientific Working Group for the Analysis of Seized Drugs,SWGDRUG)分析谱库检索和文献查询获得的信息资料进行比对,鉴定为去氯依替唑仑。结论该方法具有分析简便、快速的特点,可以用于实际案件的检测。     

Quantitative analysis of tropane alkaloids in biological materials by gas chromatography-mass spectrometry

A simple and rapid method for quantitation of tropane alkaloids in biological materials has been developed using an Extrelut column with gas chromatography-mass spectrometry (GC-MS). Biological materials (serum and urine) were mixed with a borate buffer and then applied to an Extrelut column. The adsorbed tropane alkaloids were eluted with dichloromethane before a GC-MS analysis. Atropine-d(3) was used as an internal standard. The extracted tropane alkaloids were converted to trimethylsilyl derivatives prior to GC analysis, to improve the instability of tropane alkaloids from heating and the property of them for a GC column. The recoveries of the compounds, which had been spiked to biological materials, were more than 80%. The GC separation of the derivatives from endogenous impurities was generally satisfactory with the use of a semi-polar capillary column. Tropane alkaloids showed excellent linearity in the range of 10-5000 ng/ml and the limit of detection was 5.0 ng/ml for biological materials. The present method is simple and more rapid than those previously reported, and was applied to a poisoning case. It is useful for the routine analysis of tropane alkaloids in cases of suspected tropane alkaloids poisoning.     

54例氯化琥珀胆碱中毒案件的法医学分析

目的观察分析氯化琥珀胆碱中毒案件的法医学表现,以期提高氯化琥珀胆碱中毒的检验鉴定。方法收集54例氯化琥珀胆碱中毒案例,通过病理学、毒理学变化及案件特点进行回顾性分析,观察氯化琥珀胆碱中毒的检验鉴定规律。结果氯化琥珀胆碱中毒的病理学表现以急性肺淤血、肺水肿等一般猝死改变为主,部分死者心肌排列紊乱及断裂。死者心血中均检见琥珀胆碱成分,皮肤组织部分检见琥珀胆碱成分。结论氯化琥珀胆碱中毒具有死亡快、手段隐蔽、难以抢救、易漏检等特点。对于猝死案件、死因可疑案件应将氯化琥珀胆碱作为常规检验指标,防止此类案件的未检或漏检。     

Pharmacokinetic profile of paraquat following intravenous administration to the rabbit

Pharmacokinetic studies of paraquat in rabbits were performed using [methyl-14C]-paraquat. Plasma concentration of paraquat following i.v. administration to the rabbit was fitted to a 3-exponential function of pharmacokinetic analysis. Distribution and elimination were discussed on the basis of the 3-compartment open model system, which has a central and two peripheral compartments. Computer simulations of paraquat levels in each compartment indicated that the slow-uptake peripheral compartment contained a greater amount of paraquat than the central or the fast-uptake peripheral compartment. On the basis of the present results of the computer simulations in company with tissue distributions of paraquat reported by the other investigators, it is likely that the slow-uptake peripheral compartment contains the lung. In cases of paraquat-induced renal failures, the paraquat levels of the slow-uptake peripheral compartment were remarkably higher than in cases of normal renal functions. Histology of the rabbit tissues 7 days after i.v. administration of paraquat revealed that marked changes were observed only in the kidney, suggesting some renal failures induced by paraquat. In spite of the high concentration of paraquat, which was presumed with the computer simulations in this study, the rabbit lung showed a remarkable resistance to paraquat toxicity. The histology studies suggested the complexities of paraquat toxicity to the rabbit. The lung toxicity in the rabbit would be caused by not only the paraquat concentration in the lung but also some biochemical parameters in the tissue related to the mechanisms of paraquat toxicity.     

Chemical fingerprinting of unevaporated automotive gasoline samples

The comparison of two or more samples of liquid gasoline (petrol) to establish a common origin is a difficult problem in the forensic investigation of arsons and suspicious fires. A total of 35 randomly collected samples of unevaporated gasoline, covering three different grades (regular unleaded, premium unleaded and lead replacement), were examined. The high-boiling fraction of the gasoline was targeted with a view to apply the techniques described herein to evaporated gasoline samples in the future.A novel micro solid phase extraction (SPE) technique using activated alumina was developed to isolate the polar compounds and the polycyclic aromatic hydrocarbons (PAHs) from a 200microl sample of gasoline. Samples were analysed using full-scan gas chromatography-mass spectrometry (GC-MS) and potential target compounds identified. Samples were then re-analysed directly, without prior treatment, using GC-MS in selected ion monitoring (SIM) mode for target compounds that exhibited variation between gasoline samples. Principal component analysis (PCA) was applied to the chromatographic data. The first two principal components (PCs) accounted for 91.5% of the variation in the data. Linear discriminant analysis (LDA) performed on the PCA results showed that the 35 samples tested could be classified into 32 different groups.     

Chemical profiling of heroin recovered from the North Korean merchant vessel Pong Su

Heroin samples, seized from the North Korean merchant vessel Pong Su in Australian waters, were analyzed to determine geographic origin. Duplicate samples were analyzed by the National Measurement Institute's Australian Forensic Drug Laboratory and the United States Drug Enforcement Administration's Special Testing and Research Laboratory. Alkaloid ratios were determined by both liquid chromatography-diode array detection (LC-DAD) and capillary electrophoresis-diode array detection (CE-DAD) techniques. Acid/neutral manufacturing by-products were determined by solvent extraction followed by gas chromatography-mass spectrometry (GC-MS). Solvents, trapped in the heroin particles during manufacture, were detected by both static headspace GC-MS and purge and trap GC-MS. The alkaloid ratios obtained were consistent with heroin of a Southeast Asian (SEA) origin and principal component analysis of the alkaloid results demonstrated the presence of at least four subgroupings within the seizure. The solvent analysis detected diethyl ether and ethyl acetate, solvents typically seen in SEA heroin. However, the acid/neutral analysis revealed compounds not normally seen in heroin of a SEA origin. Furthermore, sterol-like molecules, always detected in the acid/neutral analysis of SEA heroin, were absent from the Pong Su samples. The Pong Su heroin, although similar to SEA heroin, has sufficient differences to classify it as having an unknown origin at the time of this writing.     

Influence of Paraquat on Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) Infesting Minced‐beef Substrates in Kelantan,Malaysia

This study investigated the influence of paraquat, a prevalent poison used by suicides, on initial oviposition and development of Chrysomya megacephala (Fabricius) using minced‐beef substrates. Paraquat in lethal dose for human (40 mg/kg), two times the lethal dose (80 mg/kg) and five times the lethal dose (200 mg/kg) were mixed thoroughly with respective minced‐beef substrates (1 kg each) that were decomposed in a shaded habitat fully protected from rain. Results of four replications of the above experiment revealed that the presence of paraquat neither delayed initial oviposition nor prolonged the developmental stages of C. megacephala. Therefore, estimation of postmortem interval (PMI) based on empirical baseline data obtained using animal models devoid of any poisons would still be appropriate for estimating PMI in paraquat‐related deaths.