固相提取在毒物分析中的应用研究

应用GC、GC/MS研究了尿、肝、胃组织用液- 液提取法制样引入样品中的有机组分;考查了十几种树脂稳定性、吸脱性能.选用的GDX-403树脂作吸附剂具有稳定性好、吸附回收率高的特点,当苯巴比妥浓度为2.96mg/ml,吸附平衡回收率达98.8%.净化巴比妥类药物具有样品图谱清晰、无干扰、吸脱率再现性好的优点.     

Morphine Concentrations in Stomach Contents of Intravenous Opioid Overdose Deaths

Abstract:  Death caused by heroin overdose is almost always the result of intravenous injection of the drug in Australia. We briefly describe a case where a heroin overdose was initially thought to be the result of oral ingestion of the drug, primarily as a result of higher concentrations of morphine in stomach contents than in blood. During the subsequent criminal trial and investigation, however, the issue of the entero-hepatic circulation of morphine was raised as a possible reason for the presence of morphine in the stomach contents. In this study, we report on the distribution of opioids in blood, stomach contents, urine, liver, and bile in 29 deaths caused by intravenous heroin overdose. The mean total and free blood morphine concentrations were 0.60 and 0.32 mg/L , respectively, and the mean stomach contents total morphine concentration was 1.16 mg/kg. All cases had detectable morphine in the stomach contents, and 24 of 29 cases (83%) had higher concentrations of total morphine in stomach contents than in blood. The mean total morphine concentration in bile was c. 100 times that in blood, and the liver total morphine concentration averaged twice that of blood levels. We conclude that the entero-hepatic circulation of morphine and subsequent reflux of duodenal contents back into the stomach can result in the deposition of morphine in gastric contents. Consequently, the relative levels of opioids in blood and stomach contents cannot be used to determine the site of administration of the drug.     

Analysis of N,N-diethyl-m-toluamide (DEET) in human postmortem specimens

N,N-diethyl-m-toluamide (DEET) levels in postmortem specimens of stomach and contents, blood, liver, and urine are reported following ingestion of the compound. DEET was analyzed by gas chromatography with an OV-101 column and a nitrogen phosphorus detector. The presence of the compound in the four postmortem specimens was confirmed by mass spectrometry.     

Quantitative determination of sibutramine in adulterated herbal slimming formulations by TLC-image analysis method

A simple thin layer chromatographic (TLC)-image analysis method was developed for rapid determination and quantitation of sibutramine hydrochloride (SH) adulterated in herbal slimming products. Chromatographic separation of SH was achieved on a silica gel 60 F(254) TLC plate, using toluene-n-hexane-diethylamine (9:1:0.3, v/v/v) as the mobile phase and Dragendorff reagent as spot detection. Image analysis of the scanned TLC plate was performed to quantify the amount of SH. The polynomial regression data for the calibration plots showed good linear relationship in the concentration range of 1-6 μg/spot. The limits of detection and quantitation were 190 and 634 ng/spot, respectively. The method gave satisfactory specificity, precision, accuracy, robustness and was applied for determination of SH in herbal formulations. The contents of SH in adulterated samples determined by the TLC-image analysis and TLC-densitometry were also compared.     

用改性热塑性树脂制模提取立体痕迹的研究

目的提出一种采用改性热塑性树脂来提取案发现场立体痕迹的新方法。方法利用市场上常见的热塑性高分子合成树脂,通过对其熔融流动性及指数的改变,使之能适应提取立体痕迹的需要,并与常用的硅橡胶提取材料的性能测试数据进行了分析比较。结果该方法提取的立体痕迹模型反映细微特征明显。结论操作方法简便快捷,性能更为优越,易于收藏保存。     

The determination of toxic metals in simulated stomach contents by energy dispersive X-ray fluorescence analysis and a fatal case of mercury poisoning

Soup is used as a simulated stomach contents matrix to determine the lower level of detection for 16 metals. All of the metals can be detected at the levels which might be expected for acute fatal doses even if the stomach contents are considerably diluted. However where small doses are administered over a prolonged period this method may not be sufficiently sensitive. A case of fatal poisoning by the ingestion of mercuric chloride is described to illustrate the effectiveness of the method. In this case mercury was also detected and determined at highly significant levels in blood and liver by the same technique. This energy dispersive X-ray fluorescence (EDXRF) method is easy to use, rapid and non-destructive.     

The appropriate use of subpopulation corrections for differences in endogamous communities

The bioluminescence response of two genetically modified (lux-marked) bacteria to potentially toxic compounds (PTCs) in stomach contents was monitored using an in vitro assay. Cells of Escherichia coli HB101 and Salmonella typhimurium both carrying the lux light producing gene on a plasmid (pUDC607) were added to stomach contents containing various concentrations of organic and inorganic compounds. There was some variability in the response of the two biosensors, but both were sensitive to the herbicides glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T); pentachlorophenol (PCP), and inorganic poisons arsenic and mercury at a concentration range likely to be found in stomach contents samples submitted for toxicological analysis. This study demonstrates that biosensor bioassays could be a useful preliminary screening tool in forensic toxicology and that such a toxicological screening should include more than one test organism to maximise the number of PTC's detected. The probability of false positive results from samples containing compounds that may interfere with the assay such as over-the-counter (OTC) drugs and caffeine in tea and coffee was also investigated. Of the substances tested only coffee has the potential to cause false positive results.     

溴敌隆及其代谢物-苄叉丙酮在犬体内的死后分布

目的研究溴敌隆及其代谢物-苄叉丙酮在中毒致死犬体内死后分布规律,为溴敌隆中毒检材的采取提供实验依据。方法分别经口给予犬2倍和4倍LD_(50)溴敌隆,待其死亡后迅速解剖取材,气相色谱-质谱联用法测定心血、外周血、尿、胆汁、心、肝、脾、肺、肾、脑、左下肢肌、膀胱、胃、胃内容、胰等脏器和体液中溴敌隆和代谢物-苄叉丙酮的含量。结果犬经2倍和4倍LD_(50)溴敌隆灌胃染毒后3d开始出现出血症状,(178.40±20.94)h后死亡。溴敌隆和代谢物-苄叉丙酮在各组织脏器及体液中的死后分布为:溴敌隆2LD_(50)组溴敌隆:胆汁尿、肝、心、肾心血、外周血、脾、肺等;苄叉丙酮:胆汁、尿、心血、外周血、肺、胃内容中含量高于其他脏器。溴敌隆4LD_(50)组溴敌隆:胆汁、尿肝、外周血心血、胃内容物等脏器。苄叉丙酮:胆汁、尿、肺浓度高于其他脏器。结论溴敌隆及其代谢物-苄叉丙酮在中毒致死犬体内死后分布不均匀,溴敌隆在胆汁、尿、肝脏、心血和外周血含量较高,代谢物-苄叉丙酮在胆汁、尿、肺较高。胆汁、尿、肝脏、心血、外周血可作为疑似溴敌隆中毒毒物分析的检材。     

Three-Dimensional Analysis of Cartridge Case Double-Casts

Due to the shot-to-shot variability in tool mark reproduction on fired cartridge cases, a method of replication is needed for the creation of training and testing sets. Double-casting is one method that has been used for this application, but the accuracy and variability of this method needs to be characterized. Three firearms were used to fire 25 cartridges each to create the master cartridge cases. The double-casting method consists of creating a silicone mold of the master cartridge case. A plastic resin mix is then poured into the mold to create the double-cast reproduction. Fifteen double-casts of each of the 75 fired cartridge cases were created across different silicone molds to analyze within- and between-mold variability. The master cartridge cases and double-casts were scanned with a confocal microscope (Sensofar® S neox) to create three-dimensional representations of the surfaces. Two similarity metrics were used for the objective comparison of the double-casts to their master cartridge cases: the areal correlation coefficient (ACCF_MAX) and the number of congruent matching cells (CMC). The ACCF_MAX and CMC data, along with visual examinations, showed that the double-casting method produces accurate reproductions. Within-mold variability was found to be minimal, and between-mold variability was low. These results illustrate that double-casting can be applied for training and testing purposes.     

Accidental fatal poisoning by Nicotiana glauca: identification of anabasine by high performance liquid chromatography/photodiode array/mass spectrometry

A method, based on reversed phase high performance liquid chromatography (HPLC) was developed for the detection and quantification of anabasine, the toxic alkaloid of Nicotiana glauca, in forensic applications. A standard solid phase extraction (SPE) method was used for the extraction of anabasine from viscera, but was optimized for the extraction of this alkaloid from plant material. The careful selection of mobile phase components allowed the direct coupling of electron impact (EI) and Z spray mass selective detector (ZMD) of the HPLC. Under these conditions, anabasine was well separated from nicotine and could be detected on the PDA (limit of detection, LOD = 250 ng/ml), TMD (LOD = 10 microg/ml) and ZMD (LOD =1 ng/ml) detectors. Three geographically isolated N. glauca trees were analyzed for alkaloid content and it was found that both the leaves and the flowers contain anabasine. The optimized HPLC method was used to analyze two viscera samples (the stomach and contents of a mother and child who putatively died from food poisoning) and a flower exhibit. Anabasine was detected in both the viscera samples, supporting the finding that these fatalities were due to the ingestion of N. glauca accidentally collected with traditional spinach (marog). The alkaloid profile of the flower exhibit submitted with the viscera samples was similar to those obtained from flowers collected from three different N. glauca trees. The results show that anabasine and/or N. glauca poisoning can easily be confirmed using the forensic methodology described.     

DNA analysis of digested tomato seeds in stomach contents

Examination of stomach contents is one of the important steps in medical legal autopsy. Vegetative materials such as stems, roots, and seeds in stomach contents can be valuable evidence for providing investigative leads in death investigation. Currently, the identification of plant materials relies on microscopic and morphologic examination. We have found that many seeds are often protected from acid degradation during stomach digestion by their tough exterior seed coat. Tomato seeds were selected as a model system to assess DNA analysis and plant variety marker identification. The DNA-amplified fragment length polymorphism method was performed to determine if the DNA obtained from single seeds could be used for PCR analysis. From the amplified fragment length polymorphism results, some candidate markers for individualizing seeds from morphologically distinct tomatoes were identified. These data on DNA analysis of tomato seeds indicate amplified fragment length polymorphism is a viable procedure for the individualization of seeds from stomach contents in forensic investigations.     

Aspiration of gastric contents in hanging with typical position of the strangulation cord and free suspension]

Among 193 cases of hanging from the years 1978 to 1991 examined in the institute of Forensic Medicine of the Freie Universit?t Berlin 8 cases with an aspiration of stomach contents had been reported. Herefrom 3 cases were hanging in a "typical" position (suspension point at the back of the head, free suspension of the hanging body) and did not undergo resuscitation. By free suspension of the hanging body the observed massive aspiration of gastric contents only can be explained by an at least partly open connecting passage between the laryngeal entry and the entrance of the oesophagus. The post mortem flowing in of stomach contents as well as a post mortem gastro-oesophageal peristalsis seem not to be able for explicating the findings. Differences in important parameters (e.g. gastric contents, alcoholization) to the cases of hanging without aspiration were not found. Even by free suspension of the body, running noose and point of suspension in the back of the neck sometimes the connection between larynx and oesophagus may stay open, especially when by emesis a high pressure is produced by the stomach.     

Qualitative and quantitative analysis of cephradine in biological materials by high performance liquid chromatography

A reversed phase high performance liquid chromatographic method was developed for the determination of cephradine, one of the commonly used antibiotics, in biological materials. Mimic samples for stomach contents, miso soup, were applied to high performance liquid chromatography (HPLC) after centrifugation and purification by Sep-Pak C18 cartridge treatment. Serum samples deproteinized or urine samples diluted were directly injected into the HPLC. The recoveries of cephradine from these materials were 95-97% and the detection limit was 0.01 microgram/injection. This method was applied to the analysis of cephradine in stomach contents obtained by autopsy. After purification by the cartridge treatment, cephradine in the sample was identified and determined by HPLC and further confirmed by thin-layer chromatography (TLC) and mass spectrometry (MS).     

Scanning electron microscopy determination of string mozzarella cheese in gastric contents

As part of a suspected homicide investigation, a sampling of the gastric contents from the victim was forwarded to the U.S. Food and Drug Administration's Forensic Chemistry Center (FCC) for analysis of specific, selected components. The victim was known to have consumed string mozzarella cheese, as a snack, less than 24 h before his disappearance and the subsequent discovery of the body. The investigation sought to confirm or dismiss speculation the victim may have been fed a meal or eaten additional food prior to his death. Analysis of the stomach contents involved examination by stereoscopic light microscopy (SLM) and isolation, processing, and analysis of suspect materials by scanning electron microscopy (SEM). Several wax-like, off-white to cream-colored objects were noted by SLM examination and removed from the gastric contents. Through a series of fixation, sectioning, drying, and coating steps, these objects were prepared for analysis by SEM. Comparison of the suspect material with laboratory control string mozzarella cheese showed excellent correlation between the analyzed samples, confirming the suspect material from the stomach contents as string mozzarella cheese.     

Separation of stomach contents using the sieve-tower technique]

The authors present a method to separate and preserve stomach contents for forensic purpose. Analysis by "sieve tower" technique is simple and quickly done during autopsy. Solid phases of stomach content are arranged size up and can be stored for subsequent examinations. With the fluid phase drug analysis or microscopic analysis to confirm identy of the foodstuffs may be done. By adding alcohol (70%) enzymatic digestion and bacterial degradation of the stomach content are stopped.     

A carpipramine related fatality

A fatality following ingestion of the tricyclic antidepressant carpipramine (Prazinil) and ethyl alcohol is described. Carpipramine was quantitated by high performance liquid chromatography. The concentration of carpipramine was 2.0 mg/L in blood and 0.44 mg/L in urine. Ethyl alcohol was measured by headspace gas chromatography and found to be 105 mg/dL in blood and 55 mg/dL in the urine. Quantitative analysis of stomach contents was positive for carpipramine by thin-layer chromatography. To our knowledge, this is the first reported fatality involving carpipramine.     

Chloral hydrate overdose: trichloroethanol detection by gas chromatography/mass spectrometry.

A case is presented where an individual ingested a fatal dose of chloral hydrate. Trichloroethanol (TCE), the metabolite of chloral hydrate, was initially identified by the Fujiwara reaction and quantified by gas chromatography/mass spectrometry in blood )127 mg/l), urine (128 mg/l) and stomach contents (25 mg total).     

Postmortem Fluid Concentrations of Heroin Biomarkers and Their Metabolites

Only limited data exist concerning the utility of complementary specimens in heroin-related deaths. As such, this report employed a validated LC-MS-MS method to quantify 6-monoacetylmorphine (6-MAM), 6-acetylcodeine (6-AC), and their metabolites morphine and codeine in blood with (BN) and without preservative (B) and the additional unpreserved specimens of vitreous humor, urine, stomach contents, and bile from 20 postmortem cases in which heroin was the primary cause of death. The median concentration of 6-MAM in BN was 0.011 mg/L, B was 0.008 mg/L, urine was 0.186 mg/L, vitreous humor was 0.022 mg/L, stomach contents was 0.147 mg/L, and bile was 0.012 mg/L. Only one case was found to be positive for 6-AC in B (case 6, 0.002 mg/L), and the median concentration of 6-AC was 0.002 mg/L in BN, 0.012 mg/L in urine, 0.003 mg/L in vitreous humor, 0.057 mg/L in stomach contents, and 0.004 mg/L in bile. These findings present new information on the distribution of these analytes in complementary matrices and support their inclusion for accurately determining the role of heroin in opioid-related deaths.     

扫描电镜-能谱仪在毒物检验中的应用

目的建立扫描电镜-能谱仪检验氰化钠的方法。方法应用扫描电镜-能谱仪及化学反应法对案件的茶水和死者胃内容中的氰化钠成分进行检验。结果检验出了氰化钠成分。结论与传统分析方法相比,该方法具有快速、简便、准确以及不破坏试样的特点。     

Sudden infant death and liver phosphoenolpyruvate carboxykinase analysis

In an effort to substantiate the impaired gluconeogenesis-terminal hypoglycemia hypothesis of sudden infant death syndrome (SIDS), 52 infants ranging from 3 weeks to 7 months of age which had been brought to autopsy were studied. The stomach contents, vitreous humor glucose concentrations, hepatic glycogen content and hepatic phospho-enolpyruvate carboxykinase (PEPCK) activity were measured as part of the laboratory component of the postmortem investigation. The stomach contents, vitreous humor glucose concentrations and liver glycogen content were similar in SIDS/and non-SIDS victims. PEPCK activity was, however, significantly lower in SIDS (p < 0.001) victims and in SIDS with other findings (p < 0.01) victims when compared to non-SIDS victims. Despite the fact that SIDS victims had lower hepatic PEPCK activity and hence potentially lower gluconeogenic capacity, terminal hypoglycemia could not be demonstrated in this group as compared to the SIDS with other findings and the non-SIDS infants. The impaired gluconeogenesis-terminal hypoglycemia hypothesis thus could not be substantiated.