Accidental death resulting from acetylene cylinder impact

Acetylene is an inflammable gas commonly used for welding in small-scale industries. We present a case of a 34-year-old male welder who died following injuries sustained from explosion of an acetylene gas-welding cylinder. In this case report, we discuss the circumstances leading to the explosion of the welding cylinder, the autopsy findings, and a brief review of the literature on deaths resulting from blasts of acetylene cylinders.     

Fatality due to methyl acetylene-propadiene (MAPP) inhalation

A 33-year-old man died after intentionally inhaling a gaseous mix of methyl acetylene (propyne) and propadiene (allene) commonly known as MAPP, which is used for soldering and welding. He was found with a plastic bag securely placed over his head and a cylinder of MAPP alongside his head. The cylinder had been vented into the bag using a flexible hose. A comprehensive toxicological analysis revealed only a trace of diphenhydramine in the liver and 0.02 mg/L of morphine in the urine. Analysis of blood by headspace gas chromatography (HS-GC) detected two unknown peaks. These were determined to be the components of MAPP gas. MAPP was quantitated in femoral blood (59.6 mg/L) and brain (43.6 mg/kg) using a HS-GC method. The cause of death was attributed to acute MAPP intoxication, and the manner was determined to be suicide. A discussion on the analytical and interpretive considerations commonly encountered when analyzing volatile compounds is also presented.     

Sudden death caused by 1,1-difluoroethane inhalation

A 20-year-old man was found dead on the floor next to a computer, with a nearly full can of "CRC Duster" dust remover located next to the deceased on the floor, and an empty can of the same product on the computer desk. Toxicologic evaluation using either gas chromatography/mass spectrometry (GC/MS) or gas chromatography/flame ionization detector (GC/FID) method identified the active ingredient 1,1-difluoroethane (Freon 152a) in all tissues analyzed. Tissue distribution studies revealed highest concentration in central blood, lung, and liver. It is believed that the 1,1-difluoroethane inhalation was the cause of death.     

Maybe a new killer in illicit cocaine

This is the study of the author that refers about a case of a 46 years old man found dead inside his house, the death was related to cocaine intake. The police found the corpse laying in his bed with a sheet of newspaper rolled up and a few plastic coverings containing trace of cocaine on the desk. Toxicological analysis was performed and drug levels measured by means of gas chromatography/mass spectrometry technology. Based on the autopsy findings and toxicological results the cause of death was related to an acute intoxication due to cocaine "overdose". In addition to the presence of cocaine and smaller alkaloids, in the sheet made of newspaper rolled up and eluted of the nasal mucosas has been highlighted the presence of 2,6-disopropylnaphtalene (2,6-DIPN), a fungicidal pesticide very health hazard for human. A very easy, simple and selective gas chromatography mass spectrometry method was employed for the detection of 2,6-DIPN in the cocaine powder.     

Quantity of weapon oils at the target as a function of shooting sequence and firing distance

Five widely used gun oils were tested to see if they could be identified by gas chromatography. All oils in the test produced characteristic gas chromatograms and the test was highly sensitive in tracing the oils. Seven different weapons and various types of ammunition were used to perform firing tests involving an oil sold under the brand name of "Gun pro." The weapons were oiled and wiped dry and subsequently discharged at a cotton cloth target. Series of shots were fired from a maximal distance of 3 m, and the weapon was not cleaned between shots. Grease marks and powder-burn traces were extracted separately and the extracts, after adding an internal standard, were investigated by means of gas chromatography (gas chromatography unit by Perkin and Elmer). The largest quantities of oil were transmitted by indoor ammunition fired from a small-bore rifle. At a firing range of 20 cm, a decrease in the oil quantity could be observed up to the fourth discharge. When the firing range was varied there was a decrease in the oil quantity up to a distance of 80 cm. The first and the second discharge could be distinguished up to a firing range of 60 cm. With increasing force of the projectile and a decrease in the interior length of the gun barrel, the quantity of oil conveyed to the target also decreased. Additionally, the identifiability of the oil was investigated after firing at several layers of cloth and after storage of the samples (no losses occurred after a 1-month storage period).(ABSTRACT TRUNCATED AT 250 WORDS)     

Urinary ortho-cresol concentrations as an indicator of toluene inhalation in glue-sniffers.

In a Japanese study of glue-sniffers, urinary ortho-cresol and expired air toluene concentrations were determined by gas chromatography, and urinary hippuric acid concentrations by high performance liquid chromatography. There were significant differences among three sample groups (30 male "glue-sniffers", 13 "non-glue-sniffers" and 32 industrial workers) in their expired air toluene, urinary hippuric acid and ortho-cresol concentrations. Moreover, there was a better correlation between expired air toluene and urinary ortho-cresol concentrations than between toluene and urinary ortho-cresol concentrations than between toluene and hippuric acid. These results suggest that urinary ortho-cresol is a good indicator of toluene inhalation in glue-sniffers.     

The identification of 2-chloro-4,5-methylenedioxymethylamphetamine in an illicit drug seizure

This work outlines the unequivocal identification of the "ecstasy" analog, 2-chloro-4,5-methylenedioxymethylamphetamine, using combined gas chromatography/mass spectroscopy (GC/MS) and proton magnetic resonance spectroscopy (1H-NMR). This compound was identified along with 3,4-methylenedioxymethylamphetamine (MDMA) in an illicit tablet seizure, which included 26 off-white tablets.     

Hair analysis: self-reported use of "speed" and "ecstasy" compared with laboratory findings

Drug use histories were collected from 100 subjects recruited from the "dance scene" in and around Glasgow, Scotland. In addition, each subject donated a hair sample which was analyzed by gas chromatography/mass spectrometry (GC/MS) for amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MD MA) and 3,4-methylenedioxyethylamphetamine (MDEA). The hair samples were analyzed in two 6 cm segments or in full, ranging from 1.5 to 12 cm depending on the length of the hair. Approximately 10 mg of hair was ground to a fine powder before treatment with beta-glucuronidase/aryl sulfatase. A solid-phase extraction procedure was carried out followed by derivatization with pentafluoropropionic anhydride (PFPA). All extracts were analyzed by gas chromatography/mass spectrometry (GC/MS). Of the 139 segments analyzed, 77 (52.5%) were positive for at least one of the five amphetamines. The drug concentrations found in the hair were compared with the self-reported drug histories. A concordance of greater than 50% was found between the self-report data and levels detected in hair. However, no correlation was found between the reported number of "ecstasy" tablets consumed and the drug levels detected in hair. An increase in the average drug levels measured was observed from low to high use (number of "ecstasy" tablets/month). A large number of false negatives and a low number of false positives were observed.     

Comparative analysis of illicit heroin samples

The comparative analysis of street heroin samples is still an object of scientific discussion. A combination of a wide range of analytical techniques is necessary to obtain a valid amount of information about the sample composition, and it is impossible to define an unique analytical approach. We suggest a complete analytical sequence based on analysis of volatile compounds, opiates, diluents, adulterants and metals, by head space gas chromatography (HS/GC), gas chromatography mass spectrometry (GC/MS), thin layer chromatography (TLC), high pressure liquid chromatography (HPLC) and atomic absorption (AA) using a sample amount as low as 50-100 mg. The outlined procedure can be successfully applied to routine work, thus obtaining suitable information about a sample's chemical composition. This helps to attribute or exclude common sources of separate specimens. Results obtained on 33 street heroin samples confiscated in the metropolitan area of Rome are listed.     

Drugs and the impaired driver in Northern Ireland: an analytical survey

The techniques used to analyse 212 "under-the-limit" drink-driving blood and urine specimens for drugs during a 3-year period (1982-85) in Northern Ireland are described. In all of these specimens (representing 15% of all below-limit cases) either the police surgeon who carried out the clinical examination, or the police, strongly suspected that drugs may have been a contributory factor in driving impairment, considering the lower than expected alcohol concentration. Thirty-eight (18%) samples were found to contain significant drug(s). Benzodiazepines were the most frequently encountered group of drugs (87% of all positive cases) with diazepam being that most frequently encountered (18 cases). The analytical procedures were radioimmunoassay, gas chromatography using nitrogen selective and electron capture detection along with high performance liquid chromatography (HPLC) using ultra-violet detection. Drugs and their metabolites were identified using a mixture of these techniques along with GC/MS where possible. The usefulness of HPLC coupled with a rapid-scanning diode-array spectrophotometer is also demonstrated, the technique being particularly useful in the analysis of some of the more "difficult" benzodiazepines (e.g. lorazepam, temazepam, nitrazepam) not directly amenable to gas chromatography without derivatisation.     

Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine.     

自含墨印章印文盖印时间受老化条件的影响

目的探索利用气相色谱法较精确、定量测定自含墨印章印文盖印时间受人为老化条件的影响。方法分别在恒温烘烤、紫外线照射、纯水浸泡等人为老化条件下,测定自含墨印章印油中所含有的主要相关溶剂成份的含量变化。结果得出了主要溶剂成份在人为老化条件下其含量的变化规律以及人为老化与自然老化的对应关系。结论利用气相色谱法可以对不同保存条件下自含墨印章印文的盖印时间进行测定,为实际相关案件的检验提供了依据。     

Impurities, adulterants and diluents of illicit heroin in Denmark (Jutland and Funen)

The contents of impurities, adulterants and diluents in 77 samples of illicit heroin were determined by a combination of high-performance liquid chromatography and gas chromatography. The origin of each sample was characterized by calculating the content of the opium alkaloids in relation to the heroin content. The routes of distribution were compared by determination of the contents of caffeine, procaine and sugars. The results were used as a "chemical fingerprint" of each sample. The results indicate that it is difficult to prove, with certainty, that two samples are identical. However, in most cases, by determining the amounts of impurities, adulterants and diluents in heroin samples, it will be possible to ascertain whether two samples are different and, in many cases, to determine with reasonable certainty whether two samples are identical.     

The Differentiation of the Volatile Organic Signatures of Individuals Through SPME-GC/MS of Characteristic Human Scent Compounds

Abstract:  Human scent evidence is utilized as an investigative tool through canine scent discriminations based on the premise that human scent is an individualizing characteristic. This study describes the development of what is effectively a human scent barcode consisting of the relative ratios of an individual's "primary odor" compounds utilized to determine a reproducible and individualizing profile which can be stored in a searchable database for a proof of concept of human scent as a biometric measure. Triplicate hand odor samples were evaluated from 10 subjects utilizing solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) and compared via Spearman Rank Correlations. Narrowing the compounds considered for each subject to only those common in all three samples, or a subject's "primary odor constituents," produced a greater degree of both individualization and discrimination; at both correlation thresholds of 0.9 and 0.8, the individuals were correctly discriminated and identified in 99.54% of the cases.     

稻田水中莠去津及其代谢物的硅烷基衍生化-气质联用分析法

目的建立稻田水中莠去津及其代谢物去乙基莠去津（DEA）、去异丙基莠去津（DIA）和双去烃基莠去津（DDA）的灵敏的气质联用分析方法。方法稻田水样品用GDX501大孔树脂进行固相萃取,萃取物用N,O-双三甲硅烷基乙酰胺（BSA）进行三甲硅烷基衍生化,衍生物用选择离子监测的气质联用法分析。结果稻田水中4种分析物的检出限和测量限都不高于2ng/mL。结论该方法可用于刑事案件中莠去津毁坏稻田案件的检验。     

Gas chromatography/tandem mass-spectrometry assay for trace amounts of 3'-hydroxystanozolol

3'-Hydroxystanosolol detection in biological fluids at pg levels by gas chromatography/tandem mass spectrometry is described. Gas chromatography/high resolution mass spectrometry results can be confirmed with gas chromatography/tandem mass-spectrometry.     

尿中五氯酚和2.4-二氯-6-硝基苯酚气相色谱分析

目的建立利用气相色谱分析检测尿中五氯酚和2,4-二氯-6-硝基苯酚的方法。方法取空白尿液添加五氯酚和2.4-二氯-6-硝基苯酚标准品及内标2.4-二氯苯酚,经乙酸酐衍生化后,采用气相色谱法进行检测,并对提取方法、衍生化条件等进行考察。结果经气相色谱分析,尿中五氯酚和2.4-二氯-6-硝基苯酚可得到有效分离,无杂质干扰且峰形较好。在pH值为2条件下,以环己烷作为萃取溶剂为最佳萃取条件。衍生化优选条件为使用10灿乙酸酐并加入10μL无水吡啶,60℃反应30min。结论采用气相色谱法检测尿中五氯酚和2.4-二氯-6-硝基苯酚,方法简单、结果准确,可在实际办案中应用。     

An expert study of acute poisoning by phencyclidine derivatives

Described are the results of a complex study of different objects and beverages for the content of synthetic drugs in them, i.e. phencyclidine and tenocyclidine, by using the methods of planar and gas chromatography, UV-spectrometry and mass spectrometry/gas chromatography.     

Capillary gas-liquid chromatography separation of phenethylamines in amphetamine-positive urine samples

Good gas chromatography (GC) separation of molecules is essential for clean gas chromatography/mass spectrometry (GC/MS) confirmation of compounds. The trifluoro derivatives of ephedrine (E) and methamphetamine (MA) coelute on dimethyl silicone capillary columns, such as DB-1, which are most commonly used by chromatographers. Methods are described to separate E and MA to aid GC/MS confirmations of methamphetamine, ephedrine, or both E and MA together, whichever may be present in Enzyme Immunoassay (EIA)-analyzed amphetamine-positive urine samples. The use of the heptafluoro derivatives of E and MA on a DB-1 column, or the trifluoro derivatives of E and MA on a DB-17 column, is suggested for good gas chromatographic separation.