The analysis of clingfilms by infrared spectroscopy and thermal desorption capillary gas chromatography.

An automated thermal desorption gas chromatography technique has been adapted to analyse traces of volatile compounds in proprietary food-wrapping films. Fourteen brands of polyvinylchloride film, seven brands of polyethylene film and one polyvinylidene chloride film were discriminated. Prior infrared analysis was used to identify the polymer type. The chromatograms showed minor changes in volatiles along the length of a roll of film and major changes in films exposed to daylight or in contact with cannabis resin.     

GC/MS、GC/NPD法检测毛发中的氯胺酮

目的采用液-液萃取、衍生化和GC/MS、GC/NPD方法,进行毛发中氯胺酮定性定量分析。方法选择4-苯基丁胺为内标,毛发样本用NaOH、HCl及芳基硫酸酯酶/β-葡萄糖醛酸酶等3种方式进行水解,再进行衍生化后,采用GC/MS和GC/NPD方法定性定量分析。对不同水解和衍生化条件以及提取溶剂进行比较优化,并考察方法精密度、稳定性和检出限。结果方法的提取回收率大于95%,精密度和样品稳定性良好,日内和日间标准偏差小于6%;采用GC/NPD和GC/MS直接分析毛发中的氯胺酮,检出限为0.2ng/mg和2.0ng/mg,线性范围为10.0～250.0ng/mg,相关系数均大于0.99;采用酰化衍生化后分析,GC/NPD和GC/MS检出限分别提高至0.1ng/mg和0.2ng/mg。结论该方法回收率高、检测限低,可以用于毛发中氯胺酮的定性定量分析检验。     

Identification of inorganic anions by gas chromatography/mass spectrometry

Inorganic anions were identified by using gas chromatography/mass spectrometry (GC/MS). Derivatization of the anions was achieved with pentafluorobenzyl p-toluenesulphonate (PFB-Tos) as the reaction reagent and a crown ether as a phase transfer catalyst. When PFB-Br was used as the reaction reagent, the retention time of it was close to those of the derivatized inorganic anions and interfered with the analysis. In contrast, the retention time of PFB-Tos differed greatly from the PFB derivatives of the inorganic anions and the compounds of interest could be detected without interference. Although the PFB derivatives of SO4, S2O3, CO3, ClO4, and ClO3 could not be detected, the derivatives of F, Cl, Br, I, CN, OCN, SCN, N3, NO3, and NO2 were detected using PFB-Tos as the derivatizing reagent. The inorganic anions were detectable within 30 ng approximately, which is of sufficient sensitivity for use in forensic chemistry. Accurate mass number was measured for each PFB derivative by high-resolution mass spectrometry (HRMS) within a measurement error of 2 millimass units (mmu), which allowed determination of the compositional formula from the mass number. In addition, actual analysis was performed successively by our method using trial samples of matrix.     

Unconjugated morphine in blood by radioimmunoassay and gas chromatography/mass spectrometry

Morphine, the active metabolite of heroin, is rapidly inactivated by glucuronidation at the 3 carbon. Unconjugated (pharmacologically active) morphine was measured in postmortem blood by radioimmunoassay using an antibody-coated tube kit. The kit shows less than 0.2% cross-reactivity with codeine and morphine-glucuronide. Unconjugated morphine concentrations were confirmed by gas chromatography/mass spectrometry (GC/MS) using deuterated morphine as the internal standard. The blood was precipitated with 10% trichloroacetic acid (TCA) and concentrated hydrochloric acid (HCl), centrifuged, and decanted. The supernatant was then either diluted (unhydrolyzed) or heated to 100 degrees C, 30 min (hydrolyzed), followed by a wash with 4:1 chloroform:isopropranol. The upper aqueous layer was then saturated with sodium bicarbonate (NaHCO3) and extracted with 4:1 chloroform:isopropranol. The organic layer was evaporated, derivatized with trifluoroacetic anhydride (TFA), and analyzed by selected ion monitoring (SIM) GC/MS. Comparison of the results for unconjugated morphine by radioimmunoassay and unhydrolyzed morphine by GC/MS gave a correlation coefficient of r = 0.98, n = 100. Unconjugated morphine ranged from 0 to 100% of total morphine with a mean of 42%, n = 200, for heroin or morphine involved deaths. Review of 56 putative rapid deaths gave a mean of 68% unconjugated morphine with a range of 26 to 100%. The ratio of unconjugated to total morphine was found to be stable in postmortem blood after more than a year of storage at room temperature, within the precision of the method.     

Surface-sampling and analysis of TATP by swabbing and gas chromatography/mass spectrometry

The method of sample recovery for trace detection and identification of explosives plays a critical role in several criminal investigations. After bombing, there can be difficulties in sending big objects to a laboratory for analysis. Traces can also be searched for on large surfaces, on hands of suspects or on surfaces where the explosive was placed during preparatory phases (e.g. places where an IED was assembled, vehicles used for transportation, etc.).In this work, triacetone triperoxide (TATP) was synthesized from commercial precursors following reported methods. Several portions of about 6 mg of TATP were then spread on different surfaces (e.g. floors, tables, etc.) or used in handling tests. Three different swabbing systems were used: a commercial swab, pre-wetted with propan-2-ol (isopropanol) and water (7:3), dry paper swabs, and cotton swabs wetted with propan-2-ol. Paper and commercial swabs were also used to sample a metal plate, where a small charge of about 4 g of TATP was detonated. Swabs were sealed in small glass jars with screw caps and Parafilm^® M and sent to the laboratory for analysis. Swabs were extracted and analysed several weeks later by gas chromatography/mass spectrometry. All the three systems gave positive results, but wetted swabs collected higher amounts of TATP. The developed procedure showed its suitability for use in real cases, allowing TATP detection in several simulations, including a situation in which people wash their hands after handling the explosive.     

SPE—GC／MS、GC／NPD法检测血液中苯丙胺类毒品

目的利用GC／MS、GC／NPD与固相萃取（SPE）技术相结合,建立血液中苯丙胺类毒品的定性定量分析方法。方法采用Bond—ElutCerti{y固相柱、甲醇淋洗、二氯甲烷／异丙醇／氨水（78／20／2）洗脱固相萃取分离提取,比较了不同PH体系、稀释状态、洗脱溶剂对提取回收率的影响,建立血液中苯丙胺类毒品的GC／MS、GC／NPD定性定量分析方法。结果以GC／NPD分析AM、MA、MDA和MDMA浓度在15ng／mL-2000ng／mL、10ng／mL～1600ng／mL、20ng／mL-3000ng／ml、20ng／mL-3000ng／mL范围内线性关系良好,AM、MA、MDA和MDMA的检测限分别为10ng／mL、8ng／mL、15ng／mL、15ng／mL,方法平均回收率大于85％,标准偏差小于5％,GC／MS-Scan检测限分别为40ng／mL、32．0ng／mL、60．0ng／mL、60．0ng／mL。结论此方法可满足苯丙胺类毒品滥用者的血液定性定量分析。     

Determination of cocaine in human hair by gas chromatography/mass spectrometry

A qualitative method for the determination of cocaine alone without its metabolites in human hair by gas chromatography/mass spectrometry (GC/MS) was developed. The assay used helium as carrier gas, a 30-m bonded phase fused silica OV-1 capillary column, and solid injection at 290 degrees C evaporator temperature. The cocaine concentrations in hair were determined also by radioimmunoassay (RIA). The values obtained are the sum of cocaine and its metabolites. Both GC/MS and RIA meet the requirements for the determination of drug abuse by two different methods in forensic science.     

Detection of methadone in human hair by gas chromatography/mass spectrometry

Determination of methadone in human hair by gas chromatography/mass spectrometry was described. Helium as carrier gas, a 30-m bonded phase-fused silica DB-1 capillary column and splitless injection at 230 degree C temperature were used. The concentrations of methadone and its metabolites were measured in addition by radioimmunoassay (RIA). Both methods GC/MS and RIA showed the presence of methadone in human hair.     

Intratracheal gas analysis for volatile substances by gas chromatography/mass spectrometry--application to forensic autopsies

Intratracheal gas analysis was carried out by gas chromatography/mass spectrometry (GC/MS) in 20 burned body cases (13 males and 7 females). Volatile aromatic and aliphatic hydrocarbons were detected by GC/MS using a GS-Q column with the intratracheal gas as well as the blood in 19 cases. The characteristic patterns of mass chromatograms for gasoline, kerosene (gas oil), and liquid petroleum gas could be differentiated from each other using the intratracheal gas. The burned body in one case showed no presence of volatile substances in the intratracheal gas, nor intratracheal soot, although high concentrations (1 microg/g and more) of volatile substances were detected on the clothes. The victim also had normal CO-Hb concentrations (0.1 to 0.2%) in the heart blood. The results of intratracheal gas analysis were consistent with signs of the vital reaction. In conclusion, intratracheal gas analysis provides a supportive method for diagnosing the cause of death in burned bodies, and yields for at least 48 hours valuable information on volatile hydrocarbons (being detected in deliberate or accidental fire cases) to which the body had been exposed just before death.     

气相色谱/质谱检验合成大麻素K3中AKB48

目的建立较为快速准确的合成大麻素K3中AKB48的气相色谱/质谱检验方法。方法对进样口温度、初始柱温、柱流速及质谱采样率等4项色谱及质谱实验参数进行考察优化。结果 GC/MS检验合成大麻素K3中AKB48的优化条件为:进样口温度280℃,柱初始温度80℃,柱流速为2.0ml/min,质谱采样率为2。结论该方法具有快速、准确、灵敏等优点,可用于K3中AKB48的定性检验鉴定。     

Differentiation of side chain isomers of ring-substituted amphetamines using gas chromatography/infrared/mass spectrometry (GC/IR/MS).

Common analytical methods used for identifying samples obtained from clandestine laboratories were evaluated for their ability to differentiate between possible amphetamine isomers and homologs. A series of ring-substituted (4-methyl, 4-methoxy, and 3,4-methylenedioxy) amphetamine and N-methylphenethylamine isomers was analyzed using color tests, thin-layer chromatography, gas chromatography/mass spectrometry (GC/MS) and GC/infrared (GC/IR). The N-acetyl derivatives of the isomers were analyzed using GC/IR/MS. GC/IR/MS readily differentiated the 4-methylphenylalkylamine isomers. MS and IR spectra were also obtained for each pair of the 4-methoxyphenylalkylamine isomers and the 3,4-methylenedioxyphenylalkylamine isomers, but differentiation via GC/IR/MS was difficult. The N-acetyl derivatives of each pair of isomers could be readily differentiated using GC/IR/MS. Good library researchable spectra for N-acetylamphetamine could be obtained for IR identification with 10 ng (on-column) and MS identification with 2 ng. The spectrometrically independent IR and MS data obtained for the N-acetyl derivatives indicated that the combination of GC/IR/MS can add a significant level of confidence in the analysis of ring-substituted arylalkylamines.     

Toxicological analysis of thiamylal in biological materials by gas chromatography/mass spectrometry

A reliable and sensitive method to analyze thiamylal in biological materials was developed, using gas chromatography/mass spectrometry (GC/MS). A quantitative determination was made by use of mass fragmentography with the lower detection limit of 0.01 microgram/g. Thiopental was used as the internal standard. Distribution of the drug in the blood and body tissues of rats was examined. The method was then used to detect thiamylal in tissues from an autopsied patient and concentration of this drug in the body materials was evaluated, from medico-legal aspects.     

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).     

Identification of volatile organic compounds in blood by purge and trap PLOT-capillary gas chromatography coupled with Fourier transform infrared spectroscopy

A purge and trap concentrator with a Tenax trap was coupled to gas chromatography-Fourier transform infrared spectrometry for the identification of volatile organic compounds in blood samples. A styrene-divinyl benzene porous layer capillary column allowed the separation of compounds such as household and medical gases, solvents and alcohol congeners. The identification limits in blood, measured by comparison to an in-house vapour phase spectrum library, generally ranged from 0.05 to 10 mg/1, depending on the analyte structure. Low molecular weight alcohols had identification limits up to 100 mg/1. Six actual casework examples were collected during a 1-year period of routine use to demonstrate the feasibility of the method.     

Identification of parent benzodiazepines by gas chromotography/mass spectroscopy (GC/MS) from urinary extracts treated with B-glucuronidase

Urinary glucuronide metabolites of the benzodiazepines were converted back to the parent molecules after treatment with B-glucuronidase. The benzodiazepines were extracted by a one-step liquid/liquid extraction from urine or by a liquid/solid phase extraction. For the limit of detection (LOD), a standard solution of diazepam and oxazepam was serially diluted and analyzed to the point at which a reproducible analytical result was no longer obtained. Using a temperature program and a splitless mode of injection, excellent quantitation was achieved within an 8-min run time. Based upon specimens obtained from patients under a physician's care, we have determined that urinary concentrations of the benzodiazepines > 200 ng/ml are most likely due to abuse rather than to a prescribed ingestion under strict medical surveillance. Therefore, the calibration standard and cutoff concentration for a positive result was set at 200 ng/ml.     

Forensic toxicologic analysis of methamphetamine and amphetamine in body materials by gas chromatography/mass spectrometry

Qualitative and quantitative analysis of methamphetamine and amphetamine in biologic materials was carried out by gas chromatography/mass spectrometry. A deuterium-labeled methamphetamine was employed as an internal standard with a detection limit of 50 pg and absolute stability and reproducibility. Blood was found to be the best material for estimation of the toxicity of the stimulant drug. It can be replaced by muscle which contains methamphetamine concentrations close to those of blood. The authors' classification of the toxic blood levels of methamphetamine from therapeutic to fatal doses was confirmed by additional data obtained from new case studies.     

Evaluation of extraction techniques for the forensic analysis of human scalp hair using gas chromatography/mass spectrometry (GC/MS)

Preliminary research using on-line supercritical fluid extraction/gas chromatography-mass spectrometry (SFE/GC-MS) has shown that the natural and artificial surface components of human scalp hair are reproducible and differentiable. Therefore, these components may be useful for individualization or determining demographic characteristics or both. However, it is not known how the efficiency and selectivity of on-line SFE/GC-MS compares to other extraction methods. In this study, ultrasound, Soxhlet, and pressurized-fluid extraction were used to extract 1 mg to 1.3 g portions of a composite hair sample taken from an Asian male between the ages of 10 and 18. Percent extractables ranged from 0.9% to 5.6%, depending on the solvent used, and tended to increase with solvent polarity. Chemical analysis using GC/MS showed that the extracts contained large proportions of free fatty acids, squalene, cholesterol, and various wax esters. Finally, comparisons to SFE/GC-MS showed that this method possesses adequate efficiency, no observable differences in selectivity, and greater potential for miniaturization.     

Simultaneous quantitative analysis of methamphetamine and 4-hydroxymethamphetamine in body fluids by gas chromatography/mass spectrometry

Pentodeuterated 4-hydroxymethamphetamine (HMAMP-d5), 1-(4-hydroxyphenyl)-2-(methyl-d3-amino)-propane-1,2-d2 of high quality was prepared and proved to be a most useful internal standard for quantitative analyses of 4-hydroxymethamphetamine (HMAMP), a main metabolite of methamphetamine (MAMP). Highly reliable results were obtained by gas chromatography/mass spectrometry. Simultaneously we determined also MAMP, amphetamine (AMP), 4-hydroxyamphetamine (HAMP), and HMAMP in body fluids, using two internal standards, HMAMP-d5 for HMAMP and HAMP and pentodeuterated methamphetamine, 1-phenyl-2-(methyl-d3-amino)-propane-1,2-d2, for MAMP and AMP.