A gas chromatographic method for determining acetaldehyde in cadaver blood

Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death.     

A rapid gas chromatographic method for the fingerprinting of illicit cocaine samples.

A gas chromatographic (GC) fingerprint method, based on the presence or absence of six congeners, was developed for illicit cocaine samples. The fingerprint utilizes the relative abundances of these congeners towards each other, disregarding cocaine as the main constituent, and can be expressed numerically or graphically in the form of pictograms for rapid visual comparison. The method can be applied directly to a solution of the sample in chloroform, without previous workup procedures. More than 70 unrelated samples were analyzed and a great variation was observed in the parameter composition. On the other hand, a remarkable similarity could be seen between related samples. The GC fingerprint method may be considered an important contribution for sample comparison, as is exemplified by a subdivision of the analyzed samples in different categories, based on the number and types of congeners found.     

A method for the quantitative determination of nitrites in gunshot residue cases

This paper describes a method for the quantitative determination of nitrites present in gunshot residues, using an ultraviolet-visible spectrophotometer routinely employed in colorimetric procedures. The method involves the quantitative formation of a chromophoric complex between the nitrites present in the extracted gunshot residue and the analytical reagents. The procedure has been found to be sensitive enough to detect sub-microgram quantities of nitrites in gunshot residues, and has been successfully employed in the determination of muzzle-to-target distances, a question asked often in forensic science cases.     

Heroin abuse and a gas chromatographic method for determining illicit heroin samples in Singapore.

The abuse of heroin (diacetylmorphine) in Singapore escalated sharply in 1975 and 1976, as indicated by the 35-fold increase in the number of heroin seizures and the 20-fold increase in the urine samples containing morphine since 1974. A rapid and simple GC method has been described to estimate diacetylmorphine (and caffeine). Monoacetylmorphine and acetylcodeine may be ascertained by an additional step involving acetylation. All gas chromatograms of a large number of samples analyzed consistently had the same pattern, indicating that they possibly had a common origin. This GC "fingerprint," together with the quantitative data, appears to be characteristic of the illicit Asian or Chinese type of heroin found in Singapore. The proportions of the four major ingredients in some twelve typical samples have been tabulated. Statistical data confirming the accuracy and reproducibility of the analytical method have also been presented.     

A new method for detecting diatoms in human organs

A new method for diatom detection is described. It includes an ultrasonic irradiation procedure with the use of a tissue solubilizer. The method is easy to carry out and is less time-consuming than previous techniques.     

Development of a harmonised method for the profiling of amphetamines: III. Development of the gas chromatographic method

This study focused on gas chromatographic analysis of target compounds found in illicit amphetamine synthesised by the Leuckart reaction, reductive amination of benzyl methyl ketone, and the nitrostyrene route. The analytical method was investigated and optimised with respect to introduction of amphetamine samples into the gas chromatograph and separation and detection of the target substances. Sample introduction using split and splitless injection was tested at different injector temperatures, and their ability to transfer the target compounds to the GC column was evaluated using cold on column injection as a reference. Taking the results from both techniques into consideration a temperature of 250 degrees C was considered to be the best compromise. The most efficient separation was achieved with a DB-35MS capillary column (35% diphenyl 65% dimethyl silicone; 30 m x 0.25 mm, d(f) 0.25 microm) and an oven temperature program that started at 90 degrees C (1 min) and was increased by 8 degrees C/min to 300 degrees C (10 min). Reproducibility, repeatability, linearity, and limits of determination for the flame ionisation detector (FID), nitrogen phosphorous detector (NPD), and mass spectrometry (MS) in scan mode and selected ion monitoring (SIM) mode were evaluated. In addition, selectivity was studied applying FID and MS in both scan and SIM mode. It was found that reproducibility, repeatability, and limits of determination were similar for FID, NPD, and MS in scan mode. Moreover, the linearity was better when applying FID or NPD whereas the selectivity was better when utilising the MS. Finally, the introduction of target compounds to the GC column when applying injection volumes of 0.2 microl, 1 microl, 2 microl, and 4 microl with splitless injection respectively 1 microl with split injection (split ratio, 1:40) were compared. It was demonstrated that splitless injections of 1 microl, 2 microl, and 4 microl could be employed in the developed method, while split injection and splitless injections of 0.2 microl should be avoided.     

A validated method for the analysis of cannabinoids in post-mortem blood using liquid-liquid extraction and two-dimensional gas chromatography-mass spectrometry

Phenazepam is a long-acting benzodiazepine that, unlike other benzodiazepines, is currently not scheduled as a narcotic in Finland, most other European countries or the USA. It is used as an anxiolytic, sedative-hypnotic and anti-epileptic, mainly in Russia. In Finland, as well as in some other countries, an increase in the unauthorized use of phenazepam has been observed in recent years. In the one year period between July 1, 2010 and June 30, 2011 the prevalence of phenazepam in Finland was assessed among drivers apprehended for driving under the influence of drugs (DUID), in medico-legal autopsy cases and in police confiscations of illicit drugs. In DUID cases an LC-MS/MS method preceded by solid phase extraction was used for the determination of phenazepam. In the post-mortem investigations the sample preparation consisted of liquid-liquid extraction followed by derivatization and the determination was carried out by GC-MS. The police confiscations were analysed by GC-MS. There were 141 positive phenazepam cases among apprehended drivers, representing approximately 3.5% of all confirmed drug cases (n=4007) in this time period. The median (range) phenazepam blood concentration in DUID cases was 0.061 mg/L (0.004-3.600 mg/L). The median phenazepam concentration in cases with no concomitant stimulant use was significantly higher than the overall median concentration. Phenazepam was found in 17 medico-legal autopsy cases and the median (range) blood concentration was 0.048 mg/L (0.007-1.600 mg/L). Phenazepam was not considered by the medico-legal team to be the sole cause of death in any of the cases, the majority of them being accidental opiod overdoses. There were 26 seizures of phenazepam by the Police in the time period studied, some of the batches consisted of a mixture of phenazepam and stimulant designer drugs. The data show that phenazepam abuse is a widespread phenomenon in Finland. A typical user was a male multi-drug user in his 30s. The concentration range of phenazepam among apprehended drivers and medico-legal autopsy cases was wide and the drug was usually found along with other psychoactive drugs. Therefore, although it seems likely that phenazepam contributed to impairment of driving in some DUID cases, the extent of its effect remains unclear and further studies are needed to define the concentrations causing impairment and toxicity.     

血液中丙泊酚的GC-MS分析

目的应用气质联用仪(GC-MS),建立快速、灵敏地分析血液中丙泊酚的定性定量方法。方法血液1mL,加入内标,采用液液提取方法处理,GC-MS选择离子(SIM)模式测定。结果在0.1～10μg/mL范围呈良好的线性关系,相关系数R2为0.9931,最低检测限(LOD)为0.05μg/mL。结论所建立的方法简便、快速、特异性强、灵敏度高,可满足法庭毒物分析和临床毒物分析的需要。     

Gas chromatographic method of quantitative determination of carbon monoxide in cadaver blood

A gas chromatographic method has been developed for measurement of carbon monoxide in cadaveric blood on a chromatographer with thermal conductivity detector and air oxygen as the internal standard. The error of the method is no more than 4% with the mean quadratic deviation +/- 0.18-0.33 min. The method was studied on 10 model and 30 expert blood samples. Putrefactive products did not influence the accuracy of analysis.     

家兔死后玻璃体液离子浓度检测的微量重复取样法

目的探讨微量重复取样法对兔玻璃体液样本离子浓度或元素含量检测的可行性。方法28只家兔分为3组:Ⅰ组:死后12h一次取出所有玻璃体液;Ⅱ组:死后12h微量取样50μl,连续取15次;Ⅲ组:死后120h微量取样50μl,连续取15次。分别检测样本中Ca2+、C l-、K+、Na+和磷元素的含量,并对所得数据进行统计分析。结果Ⅰ、Ⅱ、Ⅲ组左、右眼的Ca2+均数分别为1.956和2.068,1.942和1.948,2.071和2.045;C l-为111.520和121.240,116.744和117.022,106.322和106.767;K+为13.016和13.900,11.230和11.144,35.411和34.828;Na+为127.200和141.880,133.872和134.566,111.511和110.647;磷元素为0.556和0.744,0.284和0.280,5.585和5.597。3组双眼上述5种成分含量经配对t检验,其P值范围分别为0.2753~1.2365,0.1627~1.6596,0.1520~1.3446,0.2386~1.0892和0.0575~0.8195;Ⅱ、Ⅲ组的重复取样检测经方差分析,其P值为0.9433和0.8638,两组总体重复取样检测的方差分析,P值为0.8772。结论微量重复取样法对兔玻璃体液样本离子或元素含量的检测无实际影响。     

Evaluation of a commercial radioimmunoassay kit for the detection of lysergide (LSD) in serum, whole blood, urine and stomach contents

The Diagnostic Products Corporation Coat-A-Count radioimmunoassay kit for LSD in urine has been evaluated for use in forensic toxicology with a variety of sample types. The cut-offs (defined as the mean response of blank samples plus three standard deviation) for LSD in serum, haemolysed whole blood, urine and stomach contents were 0.06, 0.050-0.055, 0.18 and 0.18 ng/ml, respectively. Preliminary extraction of LSD from the samples is not usually necessary. The precision of the analysis and the recoveries from spiked samples were satisfactory. The cross-reactivities of 2-oxo-LSD, lysergic acid methyl propylamide, lysergic acid monoethylamide and nor-LSD were estimated to be 11,6,2 and 1% respectively relative to LSD (100%).     

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.