Trace Element Analysis of Rough Diamond by LA‐ICP‐MS: A Case of Source Discrimination?*,†

Abstract: Current profiling of rough diamond source is performed using different physical and/or morphological techniques that require strong knowledge and experience in the field. More recently, chemical impurities have been used to discriminate diamond source and with the advance of laser ablation–inductively coupled plasma–mass spectrometry (LA‐ICP‐MS) empirical profiling of rough diamonds is possible to some extent. In this study, we present a LA‐ICP‐MS methodology that we developed for analyzing ultra‐trace element impurities in rough diamond for origin determination (“profiling”). Diamonds from two sources were analyzed by LA‐ICP‐MS and were statistically classified by accepted methods. For the two diamond populations analyzed in this study, binomial logistic regression produced a better overall correct classification than linear discriminant analysis. The results suggest that an anticipated matrix match reference material would improve the robustness of our methodology for forensic applications.     

中毒致死者体内芬氟拉明的GC/NPD,GC/MS法测定

建立了生物检材中芬氟拉明的定性定量分析方法。体液及脏器组织经有机溶剂提取后 ,用GC/MS法进行药物筛选、定性 ,生物检材中的芬氟拉明浓度用4 -苯丁胺作内标、GC/NPD法测定。测得芬氟拉明中毒致死者的血液、尿液、肝等组织中浓度分别为7.8μg/ml、64.2μg/ml、31.3μg/g。并对尸体解剖所见及方法可行性进行讨论     

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.     

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).     

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.     

Determination of bromadiolone and brodifacoum in human blood using LC-ESI/MS/MS and its application in four superwarfarin poisoning cases

Superwarfarin poisoning is a growing health problem. A sensitive and reproducible LC-ESI/MS/MS (liquid chromatography electrospray ionization tandem mass spectrometry) method was developed and validated for the determination of bromadiolone and brodifacoum, the most commonly used superwarfarins, in human blood using warfarin-D5 as an internal standard. Bromadiolone and brodifacoum were extracted from whole blood samples by liquid-liquid extraction with ethyl acetate. Multiple-reaction monitoring (MRM) was used to detect bromadiolone and brodifacoum using precursor→product ion combinations of m/z 525→250 and 521→135, respectively. The calibration curves were linear (r(2)=0.9999) in the concentration range of 0.5-100.0ng/mL for bromadiolone and brodifacoum, with a lower limit of detection of 0.1 and 0.2ng/mL, respectively, in whole blood. This method detected trace levels of bromadiolone and brodifacoum in whole blood samples and can be used in the diagnosis of poisoned human beings.     

Gases released from tissue and analyzed by infrared and gas chromatography/mass spectroscopy techniques

Two techniques for analyzing contaminants released as gases from postmortem tissues were described and compared. One technique used gas chromatography/mass spectrometry (GC/MS); the other, infrared spectroscopy (IR). Brain, lung, liver, blood and urine specimens were obtained from suspected drug-overdose victims whose deaths were contributed to or caused by inhalation of unknown gases or vapors during the period immediately preceding death. Gases from the postmortem tissues and liquid samples were separately admitted into an evacuated IR gas cell, the IR spectra recorded, and gas samples then removed for GC/MS analysis. Nitrous oxide, glue, and paint solvent constituents were identified and measured. Only the brain and lung tissues contained measurable amounts of inhalants. Both IR and GC/MS methods were adequate for normal confirmatory analyses; the GC/MS system was judged superior for fast routine efforts normally hampered by incomplete sample history.     

Identification of selected psychopharmaceuticals and their metabolites in hair by LC/ESI-CID/MS and LC/MS/MS

Hair samples of patients of psychiatry and hair samples of suicide cases were analysed by liquid-chromatography/ionspray-mass spectrometry (LC/MS) for antidepressants and neuroleptics. Electrospray ionisation (ESI) with in-source collision induced dissociation (ESI/CID) and tandem-mass spectrometry (MS/MS) were used for drug and metabolite identification. Mass spectra library searching was performed using an ESI/CID mass spectra library and a MS/MS spectra library. Furthermore, extracted ion chromatograms were used for the detection of N-desmethyl-metabolites, which were also identified by their fragment-ion spectra. Three examples using these methods are shown: The tricyclic antidepressant maprotiline, the selective serotonin receptor inhibitor (SSRI) citalopram and their desmethylmetabolites as well as the neuroleptic pipamperone were detected and identified in hair extracts. For extraction powdered hair was treated by ultrasonication in methanol and solid-phase extraction was used for sample clean-up prior to LC/MS or MS/MS analysis. These examples demonstrate the power of LC/MS and LC/MS/MS for the detection and identification of drugs in hair extracts using full-scan mode and ESI/CID with library searching or using highly selective LC/MS/MS-analysis with library searching or in multiple reaction monitoring mode.     

气相色谱-串联质谱法测定血液中乙基葡萄糖醛酸苷

目的建立血液中乙基葡萄糖醛酸苷（ethyl glucuronide,EtG）的气相色谱-串联质谱（GC-MS/MS）测定方法。方法血液用乙腈沉淀蛋白,离心后,将上清液转移吹干,残留物经N,O-双（三甲基硅烷基）三氟乙酰胺衍生化,用GC-MS/MS进行检测。结果血液中EtG的检出限为0.05μg/mL,线性范围为0.1～10μg/mL（r=0.9999）。对送检案例血液检材进行EtG检测,效果良好。结论本方法适用于血液中EtG的检测。     

Determination of phenol and o-cresol by GC/MS in a fatal poisoning case

A fatality due to the ingestion of solution containing phenol and o-cresol is described. The pathological findings were typical of acute substantial poisoning. Blood, urine and stomach content were obtained during post mortem examinations. Phenol and o-cresol were identified using GC/MS. The extractions from autopsy materials were obtained as follows: by gel permeation with cyclohexane/dichloromethane from stomach content, by solid phase extraction (SPE) from urine and by deproteinization with acetonitrile from blood. The phenol and o-cresol concentrations in the samples were found, respectively, as follows: 115.0 and 5.0 microg/g in the stomach contents, 58.3 and 1.9 microg/ml in the blood, 3.3 and 20.5 microg/ml in the urine. Distributions of phenol in fatal poisonings have been reported, but, usually, colorimetry was used as the analytical method and it cannot exclude the interference of other phenolic compounds.     

液相色谱-串联质谱法分析生物检材中的河豚毒素

目的建立血液、尿液以及肝中河豚毒素(tetrodotoxin,TTX)的液相色谱-串联质谱分析方法,并进行方法学验证。方法血液、尿液和肝用1%乙酸甲醇溶液去蛋白后,上清液用固相萃取法净化,LC-MS/MS检测。结果血液、尿液和肝中TTX检出限分别为2ng/mL、2ng/mL和4ng/g。血液和尿液在4～100ng/mL、肝在5～100ng/g的范围内线性关系良好,相关系数r≥0.9973;日内精密度和日间精密度均在12.80%以内;回收率大于47.2%。结论所建方法高效、灵敏、准确,可以为河豚毒素中毒的法医学鉴定、临床诊治以及食品安全的监控提供技术保障。     

GC-MS/MS测定血液中巴比妥类安眠药物

建立GC-MS/MS测定血液中巴比妥类安眠药物的分析方法。方法通过固相萃取提取并富集血液样品中常见巴比妥类安眠药物,采用离子阱二级质谱定性并定量检测其含量,并优化萃取溶液pH值与气相色谱/二级质谱联用分析条件,对巴比妥类安眠药物进行定量分析。结果巴比妥类安眠药物检出限为0.04μg/mL～0.10μg/mL,回收率为80.3%～92.6%。结论该方法高效、简单,灵敏度高,可用于血液中巴比妥类安眠药物同时定性定量检测。     

Differentiation of Commercially Available Kratom by Purported Country of Origin using Inductively Coupled Plasma–Mass Spectrometry,

Kratom is a plant material exhibiting both analgesic and stimulant effects and is also forensically relevant since it is abused as a “legal high.” It is regulated in several countries but not scheduled in the United States at the federal level. This study used inductively coupled plasma–mass spectrometry (ICP–MS) to measure the concentrations of 13 elements in 19 kratom samples obtained from an online distributor selling kratom, from Borneo, Malaysia, Indonesia, Thailand, and Vietnam, for the purpose of using the elements to discriminate among purported country of origin, “suborigin,” and strain. Analysis of variance revealed statistical differences in concentrations of elements from each group, while discriminant function analysis (using leave-one-out classification) successfully classified kratom samples by their purported country of origin (100%), “suborigin,” (100%), and strain (86%). Our method illustrates the possibility of utilizing ICP–MS for determination of commercially available kratom samples by purported origin, “subororign,” or by product line.     

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.     

Detection of malathion in a victim by gas chromatography/negative ion chemical ionization mass spectrometry

We experienced an autopsy case in which a 53-year-old woman committed suicide by ingesting allegedly a certain agricultural chemical. The blood and stomach contents, after extraction with acetonitrile and chloroform, were subjected to analysis by gas chromatography (GC)/negative ion chemical ionization (CI) mass spectrometry (MS). By total ion monitoring in the negative CI mode, a large peak appeared. The mass spectrum of the peak showed a strong anion at m/z 157, suggesting the presence of an organophosphorus pesticide. By measuring its spectrum in the positive electron impact (EI) mode, it was identified as malathion. The selected ion monitoring in the negative CI mode showed that the malathion peak was not interfered with by any impurities, and its background was very low. The sensitivity in the negative CI mode was about 5-10 times higher than that in the positive EI mode. Our data show that the GC/negative ion CI MS is useful for both screening and sensitive quantitation of organophosphorus pesticides.     

Assessment of the Effects Exerted by Acid and Alkaline Solutions on Bone: Is Chemistry the Answer?

The treatment of corpses with extremely acid or basic liquids is sometimes performed in criminal contexts. A thorough characterization by chemical analysis may provide further help to macroscopic and microscopic analysis; 63 porcine bone samples were treated with solutions at different pH (1–14) for immersion periods up to 70 days, as well as in extremely acidic sulfuric acid solutions (9 M/18 M) and extremely basic sodium hydroxide. Inductively coupled optical emission spectrometry (ICP‐OES)/plasma mass spectrometry (ICP‐MS), Fourier transform infrared spectroscopy (FT‐IR), energy dispersive X‐ray analysis (EDX), X‐ray powder diffraction (XRPD), and scanning electron microscopy (SEM) showed that only the sulfuric acid solution 18 M was able to completely dissolve the sample. In addition, chemical analysis allowed to recognize the contact between bone and substances. Hydrated calcium sulfate arose from extreme pH. The possibility of detecting the presence of human material within the residual solution was demonstrated, especially with FT‐IR, ICP‐OES, and EDX.     

Organic explosives analysis using on column-ion trap EI/NICI GC-MS with an external source

In this study, a standard method by gas chromatography coupled with mass spectrometry (GC/MS) for the analysis of classical organic explosives was developed. This method was validated in the EI mode, based on the XPT 90-210 standard method. Detection limits (LOD) and quantitation limits (LOQ) were both determined using electronic impact (EI) and negative ion chemical ionization (NICI) modes. These were compared and results showed that in the NICI mode, detection limits were lower than in the EI mode, thus NICI mode appeared to be the best way to analyze nitrate esters. Results of ion trap MS detection were then compared with those obtained in a previous study with single quadrupolar technology. Major ions that were obtained using ion trap MS detection in these two modes were reported.     

UPLC-MS/MS测定全血中的氯丙嗪

目的建立全血中氯丙嗪的UPLC-MS/MS分析方法。方法采用乙腈沉淀蛋白,以Waters ACQUITY UPLCBEH C18柱(2.1mm×50mm,1.7μm)分离,乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,正离子方式检测,多反应离子监测模式(MRM)。结果血液中氯丙嗪在1～100ng/mL范围内线形关系良好,检出限为0.01ng/mL,回收率为81.81%～89.36%,日内、日间精密度分别为9.3%、12.1%。结论本方法准确、快速,可用于全血中氯丙嗪的定性定量分析。     

Determination of Nicotine,Cotinine and Trans‐3′‐Hydroxycotinine using LC/MS/MS in Forensic Samples of a Nicotine Fatal Case by Oral Ingestion of e‐cigarette Liquid,

Nicotine is a potent neurotoxin alkaloid and is used in e‐cigarette liquid. The LC/MS/MS method was linear over 0.01–1.0 mg/L (r² = 0.992–0.995). Limit of detection and limit of quantitation were 0.001 mg/L (S/N = 3) and 0.003 (S/N = 10). The inaccuracy and imprecision were <13.2%. The recoveries were >99.3%. A 39‐year‐old dentist was found dead lying on the floor under the couch in his dental clinic. The concentration of nicotine, cotinine, and trans‐3′‐hydroxycotinine (heart blood/peripheral blood) was analyzed as follows: 87.2/85.2 mg/L (ratio 1.0), 1.4/1.1 mg/L (ratio 1.3), and 0.012/0.0089 mg/L (ratio 1.3), respectively. The concentration of nicotine was determined to be 6734.8 mg/kg in gastric contents and 7262.0 mg/L in remaining e‐liquid. Only, high concentration of nicotine was detected in the gastric contents as well as the two pieces of evidence collected from the death scene. This fatal case resulted from oral ingestion of e‐cigarette liquid. It is estimated that at least 714 mg of nicotine was orally ingested.     

Potential of soil organic matter molecular chemistry determined by pyrolysis-gas chromatography/mass spectrometry for forensic investigations

Wetlands near urban centers may be more isolated areas and can be chosen for the disposal of bodies or used as a crime scene. The predominant soils in these areas usually have a high content of organic matter (OM), classified as Histosols. Soil organic matter (SOM) is composed of many different compounds that can be identified by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The study aimed to use Py-GC/MS to classify small amounts of organic soil in a forensic context. We sampled Histosols from five representative sites of Curitiba, Brazil. The molecular composition of the samples was determined by byPy-GC/MS. The factor analysis was carried out, and the factor scores showed a clear differentiation between the sites. Compounds indicative of relatively fresh plant material was separated from more recalcitrant and charred material. Py-GC/MS has the potential to be a useful tool to study the composition of SOM in Histosols to track the trace sample collected from a crime suspect.