Characterisation of gunshot residue from three ammunition types using suppressed anion exchange chromatography

Gunshot residue (GSR) is commonly analysed in forensic casework using either scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) or gas chromatography-mass spectrometry (GC-MS). Relatively little work has been reported on the post-discharge GSR content of non-metallic inorganic or low molecular weight organic anions to distinguish between different ammunition types. The development of an analytical method using suppressed micro-bore anion exchange chromatography (IC) is presented for the analysis of GSR. A hydroxide gradient was optimised for the separation of 19 forensically relevant organic and inorganic anions in <23min and sensitivities of the order of 0.12-3.52ng of anion detected for all species were achieved. Along with an optimised extraction procedure, this method was applied to the analysis of post-ignition residues from three selected ammunition types. By profiling and comparing the anionic content in each ammunition residue, the possibility to distinguish between each type using their anionic profiles and absolute weight is presented. The potential for interference is also discussed with respect to sample types which are typically problematic in the analysis of GSR using SEM-EDX and GC-MS. To the best of our knowledge this represents the first study on the analysis of inorganic anions in GSR using suppressed ion chromatography.     

液固界面衍生化-GC-MS法同时检验3种常见阴离子毒物

目的建立GC-MS法同时检验氰离子、亚硝酸根离子、氟乙酸根离子的方法。方法首先用阴离子交换树脂吸附检材中的CN^-、NO2^-、FCH2 COO-^，再在树脂界面上进行五氟苄基溴衍生化反应，最后用GGMS法检验衍生化产物。结果成功地解决了衍生化前3种阴离子的提取、浓缩问题，使衍生化反应得以顺利进行，衍生化产物稳定，便于使用G＆MS法检验。结论建立了一种同时检验3种常见阴离子毒物的有效方法，该方法简单、实用、灵敏、准确。     

人精浆中A型血型物质的分离纯化及理化性质研究

应用凝胶过滤、阴离子高速液相色谱及免疫亲合层析方法成功地从A型分泌型人精浆中分离、纯化了具有A型活性的精浆血型物质（SPBGS－A）。理化分析结果表明：SPBGS－A为表现单一A型活性、分子量不均一的糖蛋白。其分子量约为100KD；等电点在pH2．7～3．5之间；糖含量占72．5％；蛋白质含量占24．2％。共检出了16种氨基酸成分，其中苏氨酸、丝氨酸及脯氨酸的含量约占50％。经与其它水溶性血型物质在化学组成上进行比较，提示其可能具有一定的器官特异性。     

Tissue distribution of ethosuximide and clobazam in a seizure related fatality

The case of a six-year-old male who died in a hospital while receiving several anticonvulsant drugs is described. Phenytoin, desmethyldiazepam, clobazam (an experimental 1,5 benzodiazepine), and desmethylclobazam were quantitated in serum, liver, and brain tissue by high performance liquid chromatography. Ethosuximide was quantitated by gas chromatography. To our knowledge, this is one of few reports describing tissue concentrations of ethosuximide collected at autopsy and the first report of clobazam/desmethylclobazam tissue distribution in man.     

An infant fatality involving ajmaline

An infant fatality following accidental ingestion of ajmaline is described. Ajmaline was determined by thin-layer chromatography and infrared spectrophotometry, and quantitated by high performance liquid chromatography. The ajmaline concentration in blood was 5.5 micrograms/mL. The toxicological data relevant to the interpretation of case findings are presented.     

Capillary ion electrophoresis of endogenous anions and anionic adulterants in human urine

Normal human urine contains many anions and cations. Ionic concentrations in urine have classically been determined by spectrophotometry of color reactions, flame emission spectrophotometry, atomic absorption spectrophotometry, high performance liquid chromatography, or potentiometry with ion-specific electrodes. Capillary ion electrophoresis (CIE) is a form of capillary electrophoresis which uses the differential electrophoretic mobility of ions to perform a separation of an ionic mixture. Various salts can be added to urine specimens to abnormally elevate ionic concentrations and interfere with either immunoassay urine drug screening procedures or gas chromatographic/mass spectrometric confirmation techniques. Application of CIE for the direct detection of endogenous anions and anionic adulterants in human urine specimens was the purpose of this investigation. CIE was performed using a Waters Quanta 4000 Capillary Electrophoresis System with either direct or indirect ultraviolet absorption detection at 254 nm. CIE of 30 random normal urine specimens and 21 urine specimens suspected of adulteration was performed. Duplicate aliquots were assayed by CIE and by colorimetric technique for nitrite. Sixteen specimens had elevated concentrations of nitrite and/or nitrate. The correlation coefficient between nitrite CIE and colorimetric results was 0.9895. Three specimens had detectable concentrations of chromate and were suspected of being adulterated with "Urine Luck," an adulterant found to contain chromate. Two specimens suspected of being adulterated with bleach were found to only contain chloride, sulfate, and phosphate. CIE is applicable to forensic analysis of urine anion concentrations. CIE can easily quantitate numerous endogenous anions and offers a method to detect and/or confirm anion adulteration of urine specimens.     

A fatal case of chlorate poisoning: confirmation by ion chromatography of body fluids

A 49-year-old male chemical industry worker was admitted to intensive care with a 24-hour history of respiratory failure, vomiting, headache, stupor, arterial hypotension, and cyanosed face and limbs. He had acute haemolysis (3.9 g/L plasma haemoglobin concentration) and 30% methaemoglobinaemia. Whereas the search for alcohol, barbiturates and opiates was negative, benzodiazepines and tricyclic antidepressants were present. The patient was in fact being treated with fluvoxamine, amitryptiline, and alprazolam. As the clinical and biological signs suggested chlorate poisoning, chlorate was looked for by using an aniline color reaction. It was found in gastric content and urine. Treatment consisted in mechanical ventilation, vasoactive amines, methylene blue, plasma exchange, exchange transfusion, and haemodialysis. Despite this, the patient had several cardiac arrests and refractory metabolic acidosis. He died 12 h after his admission. Specific ion chromatography was used afterhand to assay the chlorate in various body fluids. The technique was based on a separation on an ion exchange Dionex AS 12A column coupled with conductivity detection. A quantitative estimation was carried out by using external calibration with a four-point calibration curve which was linear between 1 and 15 mg/L. The measured plasma levels of chlorate were 78 and 29 mg/L respectively before and after exchange transfusion. Gastric-lavage liquid contained 1300 mg/L of chlorate and urine 4300 mg/L. Ion chromatography, which is routinely used in environmental studies helped to confirm a massive oral intake of chlorate by measuring the corresponding blood and urine chlorate concentrations, data which had only rarely been reported previously.     

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.     

Study of losses of volatile compounds from dynamites. Investigation of cross-contamination between dynamites stored in polyethylene bags

The purpose of this work was to study the appropriateness of polyethylene bags for the preservation of explosive specimens. To this end, specimens of two types of dynamites, Goma-2 EC, containing nitroglycol (EGDN) and dinitrotoluene (DNT), and Goma-2 ECO, containing only EGDN, were placed individually inside bags and introduced into hermetically sealed glass jars, which were stored for a period of time. Losses of volatile compounds were studied by headspace analysis using gas chromatography coupled to mass spectrometry (GC-MS). The cross-contamination between dynamites was studied by using high performance liquid chromatography with mass spectrometry (HPLC-MS) to analyse the extracts obtained after a sequential solvent extraction of these specimens. Polyethylene bags permit the loss of volatile compounds since EGDN and DNT were detected in the headspaces of the jars. Moreover, cross-contamination between dynamites was also demonstrated since DNT content decreased in the dynamite containing this compound and increased in the dynamite that had not contained it.     

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.     

Analysis of 2-hydroxyimipramine in an imipramine-related fatality

A fatality following ingestion of the tricyclic antidepressant imipramine (Novopramine), acetaminophen, and ethyl alcohol is described. Imipramine, desipramine, acetaminophen, and 2-hydroxyimipramine were quantitated by high performance liquid chromatography, and ethyl alcohol by gas liquid chromatography. Concentrations of imipramine, desipramine, 2-hydroxyimipramine, and acetaminophen were: in blood--9.0, 1.1, 3.9, and 11 mg/L; in urine--92, 14, and 42 mg/L (acetaminophen not quantitated in urine). Ethyl alcohol concentration in blood was less than 10 mg/dL and 105 mg/dL in the urine by headspace gas chromatography. These findings are compared to previous reports of imipramine-related fatalities. To our knowledge, this is the first fatality reported involving imipramine where analysis included quantitation of 2-hydroxyimipramine in blood and urine.     

Optimization of solid-phase microextraction (SPME) for the recovery of explosives from aqueous and post-explosion debris followed by gas and liquid chromatographic analysis

Solid-phase microextraction (SPME) has been evaluated for the recovery of explosives residues from aqueous samples and real post-explosion solid debris samples and optimized using gas chromatography with an electron capture detector (GC-ECD) and high-performance liquid chromatography with ultraviolet detection (HPLC-UV). A modified SPME/HPLC interface utilizing dual six-port valves allowed for independent optimization of SPME desorption and injection variables that provided improved chromatographic resolution and sensitivity. A unique combination of cyano and octadecyl columns resulted in the complete separation of the 14 explosives in EPA method 8330 mixture using HPLC with good quantitative results. At the optimum SPME conditions, the limits of detection (LOD) were found to be of 5 ng/mL to 16 ng/mL of explosives in water and 10 microg/kg to 40 microg/kg of explosives from soil. The technique has been successfully applied to the analysis of real post-explosion debris and can be adapted for use in the field utilizing portable chromatographic instruments.     

A fatality involving clomipramine

A fatality following ingestion of the tricyclic antidepressant clomipramine (Anafranil), alprazolam (Xanax), and ethyl alcohol is described. Clomipramine and N-desmethylclomipramine were quantitated by high performance liquid chromatography and alprazolam by gas liquid chromatography. Concentrations of clomipramine and N-desmethylclomipramine were: in blood--0.84 and 1.4 mg/L; in urine--0.56 and 0.62 mg/L. Alprazolam concentration in blood was 0.069 mg/L. Ethyl alcohol was measured by headspace gas chromatography and found to be 375, 385, and 435 mg/dL in blood, urine, and vitreous humor, respectively. These findings are compared to previous reports of clomipramine related fatalities and alprazolam toxicity combined with ethyl alcohol.     

Coca paste: chemical analysis and smoking experiments

Several samples of Colombian and a sample of Peruvian coca paste were subjected to chemical analysis to ascertain the complexity of these products. A neutral and acid fraction and a basic fraction were analyzed by gas chromatography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS). The basic fraction was also analyzed as its trimethylsilyl (TMS) derivative. Several gasoline residue components were identified in the neutral fraction. In addition to cocaine (greater than 60% in all cases), other alkaloids were identified. Lead and manganese analyses were carried out on these samples. While all the samples contained no lead (less than 45 ppm), most of the Colombian samples contained significant amounts of manganese (greater than 5%). Preliminary smoking experiments with a Colombian coca paste sample indicated that it behaves more like free cocaine than like a cocaine sulfate salt.     

Toxicological analysis of a fatal baclofen (Lioresal) ingestion

A fatality following ingestion of the drug baclofen (Lioresal) is described. Baclofen was identified in urine by gas chromatography/mass spectrometry. After derivatization with trinitrobenzene sulfonic acid, baclofen was quantitated in serum and urine by high-performance liquid chromatography. The concentration of baclofen was 17 mg/L in serum and 760 mg/L in urine collected approximately 12 h after the overdose. To our knowledge, this is only the second reported fatality involving a baclofen overdose. The previous case did not include quantitation of baclofen in any biological fluid.     

Determination of Nitrite in Whole Blood by High‐Performance Liquid Chromatography with Electrochemical Detection and a Case of Nitrite Poisoning

Although nitrite is widely used in meat processing, it is a major toxicity hazard to children and is responsible for the blue‐baby syndrome. A simple and effective method to determine nitrite in whole blood has been devised using ion chromatography with suppressed conductivity detection. The blood sample was deproteinized by adding acetonitrile and purified with mini‐cartridges to remove hydrophobic compounds, chloride ions, and metal ions. An aliquot of the filtrate was injected onto the ion chromatography. The retention time for nitrite was 13.8 min and the detection limit of nitrite in whole blood was 0.4 μmol/L. The calibration curve was linear (r² = 0.9999) over the concentration working range. The blood nitrite concentration of a victim who attempted suicide by ingesting sodium nitrite powder was determined using the present method. The basal levels for nitrite in human blood was determined with 7.1 ± 0.9 μmol/L (n = 12).     

Rapid screening for the detection and differentiation of γ-hydroxybutyrate using ion chromatography

The analysis of gamma-hydroxybutyric acid (GHB) is problematic because it is hygroscopic, it lacks a good UV chromophore, and it undergoes heat-induced cyclization. This paper presents a new method utilizing ion-exchange chromatography (IC) with conductivity detection. The simple sample preparation, rapid analysis time, and inorganic anion detection capabilities are all advantages over the current methods. The detection of inorganic salts (formed during GHB synthesis) gives insight into the synthetic route utilized and can aid in drug seizure comparison. The developed method has a detection limit for GHB anions of 0.57 mg/L and chloride of 0.22 mg/L. A comparison of this technique with a current gas chromatography-mass spectrometry technique is presented, and a t-test found that the two methods' results are not statistically different at the 99.9% confidence level demonstrating the merits of this fast, simple, and informative IC method as a routine screening tool.     

Determination of impurities in illicit methamphetamine samples seized in Iran

In this study fifty samples of crystalline methamphetamine obtained from antinarcotics police of Iran seized during the year 2010 were analyzed. In order to determine the chemical characteristics of these samples, anion test, Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) were carried out on the samples. All of the samples containing methamphetamine tested positive for chloride anion. The range of methamphetamine hydrochloride content in these samples was 33-95%. One sample out of 50 contained no methamphetamine. The fact that 1,2-dimethyl-3-phenylaziridine was the most frequently found impurity in the analyzed samples, indicates that most of the methamphetamine samples seized in Iran have been synthesized from pseudoephedrine as starting material.     

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40 degrees C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116 +/- 0.012, 1.082 +/- 0.070 and 8.984 +/- 0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d = 1.000 was 1.040 +/- 0.040 in MAMP and 0.980 +/- 0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.