Hair analysis to document a clinical case of TCDD over-exposure

Dioxins and related compounds (furans) are persistent environmental contaminants that cause adverse biological effects. Their influence on humans is still unclear, except for accidental high-dose exposure. Chronic exposure to these compounds seems to be involved in cancer, endocrine disruption and neurobehavioral effects. For several years, a large concern about the potential health risks of dioxins is emerging in Europe and United States. The case of a 50-year-old man victim of an acute over-exposure to tetrachloro dibenzo-p-dioxin (TCDD or Seveso dioxin) is reported here with particular focus on hair investigations. The developed method involved the decontamination of the hair strand using picograde level methylene chloride, the homogenization of hair segments with scissors and their extraction in presence of 13C12-marked dioxin congeners under reflux of toluene using a Soxhlet, 8h at 130 degrees C. After reduction of the toluene fraction to 1 ml and addition of purification marker (37Cl4-2,3,7,8-TCDD), dioxins purification was achieved using three successive columns: silica, alumina/sodium sulfate and carbon/Celite columns. Finally, the toluene eluent was evaporated and the extract injected in the analytical system. After chromatographic separation, detection was achieved in single ion monitoring mode using a high resolution mass spectrometer operating in electron impact ionization mode (40 eV, minimal resolution of 10,000). The analysis of the first hair segment (0-6 cm) revealed the presence of 2,3,7,8-TCDD at 65 fg/mg when the distal one remained negative (LOQ=0.3 fg/mg). All other congeners (n=16) were in the range of those determined in the general population (0.62 and 0.89 fg/mg in the two hair segments, respectively). The extremely low dioxin levels generally found in hair specimens (low fg/mg range) lead us to analyze them using the very sensitive and specific gas chromatography-high resolution mass spectrometry apparatus. From the best of our knowledge, this is the first case of over-exposure to Seveso dioxin through hair analysis reported in the literature.     

Application of discriminant analysis to differentiate between incorporation of cocaine and its congeners into hair and contamination

The requirement to differentiate between incorporation and external contamination of drugs into hair is undisputed, in particular when dealing with compounds which are administered by sniffing or inhalation (e.g. cocaine). With the aim of making this discrimination, hair samples from cocaine (COC) users (group IN) and seized cocaine samples (group OUT) were compared regarding the parameters benzoylecgonine (BZE), ecgonine methyl ester (EME), ecgonine (ECG), anhydroecgonine methyl ester (AEME), cocaethylene (CE) and norcocaine (NCOC). Since most of these compounds may be minor by-products of COC or be formed by biotransformation or chemical degradation, the stability of each substance was carefully examined. COC was found to be converted into significant amounts of BZE, EME and ECG even under mild extraction conditions, while traces of NCOC proved to be a ubiquitous by-product of COC. Cocaine positive hairs and seized cocaine samples (diluted to relevant concentrations) were equally preprocessed and analyzed by LC-MS-MS. Out of the metabolites listed above, NCOC, CE and AEME (each normalised to COC) were significantly increased in the incorporation group (i.e. hair samples from cocaine users). Based on this approach, a statistical discriminant analysis enabled us to make a prediction (and estimation of uncertainty) for each cocaine positive hair sample as to its likelihood of belonging to the group of cocaine users or of being contaminated.     

Hair analysis for cocaine: Factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Hair samples were contaminated by rubbing with cocaine (COC) followed by sweat application, multiple shampoo treatments and storage. The samples were then washed with isopropanol for 15 min, followed by sequential aqueous washes totaling 3.5 h. The amount of drug in the last wash was used to calculate a wash criterion to determine whether samples were positive due to use or contamination. Analyses of cocaine and metabolites were done by LC/MS/MS. These procedures were applied to samples produced by a U.S. government-sponsored cooperative study, in which this laboratory participated, and to samples in a parallel in-house study. All contaminated samples in both studies were correctly identified as contaminated by cutoff, benzoylecgonine (BE) presence, BE ratio, and/or the wash criterion. A method for determining hair porosity was applied to samples in both studies, and porosity characteristics of hair are discussed as they relate to experimental and real-world contamination of hair, preparation of proficiency survey samples, and analysis of unknown hair samples.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29–316 ng/mg of hair for cocaine, 0.43–141 ng/mg of hair for benzoylecgonine and 0.93–1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

液相色谱-串联质谱法测定血液和尿液中秋水仙碱

目的建立检测血液和尿液中秋水仙碱的液相色谱-串联质谱法。方法0.5mL血液或尿液以丁丙诺啡为内标,经pH9.2硼酸盐缓冲溶液碱化后,用乙酸乙酯进行提取,在ZORBAX SB-C18液相柱(150mm×2.1mm×5μm)上以V(甲醇)∶V(20mmol/L乙酸铵和0.1%甲酸缓冲溶液)=80∶20为流动相,流速为0.2mL/min,采用电喷雾正离子模式离子化、多反应监测模式检测秋水仙碱,内标法定量。结果血液、尿液中秋水仙碱与内标丁丙诺啡色谱分离良好,秋水仙碱在0.1~50 ng/mL内均具有良好的线性,相关系数>0.9990,最低检出限为0.05ng/mL,方法回收率为94%~116%,日内与日间精密度(RSD)均小于8.5%。结论所建LC-MS-MS方法灵敏度高、操作简便、快速、准确,适用于血液及尿液等生物检材中痕量秋水仙碱成分的检测。     

Identification of acepromazine in hair: an illustration of the difficulties encountered in investigating drug-facilitated crimes

After a drug-facilitated sexual assault (DFSA), a woman was found in a drowsy state at home. She remembered having drunk an unknown beverage by the accused. Blood samples (collected 8 hours after the DFSA), two glasses, and a teaspoon seized by the police were analyzed. Acepromazine, a phenothiazine tranquilizer used in human and veterinary medicine, was detected in the residue of one of the glasses. In spite of acepromazine absence in the victim's blood, the possible use of acepromazine in the DFSA was reported to the police. Two weeks later, a suspect admitted having orally administered acepromazine to the victim. Using a liquid chromatography-tandem mass spectrometry method, this compound was subsequently detected (31 pg/mg) in a sample of the victim's hair collected a month and a half after the DFSA. A potential short elimination half-life in humans and/or the well-known in vitro degradation of acepromazine could explain the negative blood result. DFSA toxicological investigations are challenging and can be complicated when a rather unusual substance is concerned. In particular, special care should be taken when interpreting the results, taking into account elimination and/or instability data, when available.     

UPLC-MS/MS法检测血痕中常见烟草、毒品和药物成分

目的建立UPLC-MS/MS测定血痕中尼古丁、可替宁、甲基苯丙胺、氯胺酮、吗啡、O6-单乙酰吗啡、地西泮、三唑仑、艾司唑仑、佐匹克隆和利血平的方法。方法以甲醇为提取液,采用基质提取溶液配制标准溶液制作定量曲线。采用超高效液相色谱柱对待测样品进行分离;以电喷雾离子源正离子（ESI＋）模式和多反应监测（MRM）模式进行质谱分析。优化实验条件,并进行方法学评价。结果选择UPLC HSS T3色谱柱,乙腈-5mmol/L甲酸铵＋0.1%（v/v）甲酸作为流动相,甲醇作为提取溶剂。11种检测物检出限（S/N=3）和定量限（S/N=10）分别为0.04~2.82ng和0.13~7.64ng,1~500ng/mL范围内的线性关系良好。除利血平、吗啡外的检测物回收率为（53.8±5.3）%~（107.2±12.6）%。结论采用本文UPLC-MS/MS方法对血痕中11种常见烟草、毒品和药物成分进行检测,能够满足实际检案的要求,可在相关检验中选用。     

DART-MS/MS快速检测人血中的3种合成大麻素

目的使用实时直接分析-串联质谱,建立快速检测人血中的JWH-018、JWH-250和AM-2201的方法。方法用乙腈-甲醇(4:1)沉淀蛋白的方法对血样进行简单前处理,采用DART 12Dip-it自动进样系统,以正离子、MRM模式进行分析。结果血液中JWH-018、JWH-250、AM-2201可以得到有效检测,在0.02-5.00μg/m L线性关系良好,相关系数均大于0.99,检出限分别为0.016μg/m L,0.003μg/m L和0.017μg/m L,日内、日间RSD均小于15%。结论本文所建方法灵敏度高,准确性较好,方法省时省力,可用于实际案例血液中合成大麻素JWH-018、JWH-250、AM-2201的分析。     

液液萃取-超高效液相色谱-串联质谱法测定常见食用植物油中5种鸦片生物碱

目的建立酸化甲醇(pH=3)液液萃取-超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)测定常见食用植物油中5种鸦片生物碱吗啡、可待因、蒂巴因、罂粟碱、那可汀的检验方法。方法样品加入正己烷摇匀后用酸化甲醇(pH=3)提取,BEH C18色谱柱分离,乙腈(0.01%甲酸)-水(0.01%甲酸+0.05%氨水,体积比)梯度洗脱,电喷雾离子源正离子(ESI+)及多反应监测模式检测。结果结果显示5种待测成分在0.5~300ng/g范围内线性关系良好;方法检出限(S/N=3)在0.1~2ng/g间、定量限(S/N=10)在0.5~3ng/g间;回收率(20ng/g,200ng/g)在82.0%~101.4%间,相对标准偏差(RSD,n=6)为1.4%~4.2%,基质效应(20ng/g,200ng/g)在-5.3%~5.8%间,日间精密度为2.8%~6.7%。结论本方法前处理简单、耗时短,溶剂使用量少,灵敏度高,适合大批量常见食用植物油中5种鸦片生物碱的同时检测。     

Differentiation of unevaporated gasoline samples according to their brands, by SPME-GC-MS and multivariate statistical analysis

One of the aims of fire investigations is to identify associations among accelerants according to their source. In this study, 50 gasoline samples--representing five brands--were analyzed using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Chemometric procedures, such as principal component analysis (PCA) and discriminant analysis (DA), were applied to a data matrix obtained by the target compound chromatogram method, to discriminate samples according to their brand. PCA was successful in finding a natural grouping of samples according to their brand, suggesting that aromatic compounds were more useful than aliphatics for the purpose of this study. DA, if applied to aromatic compounds, gave both a classification ability and a prediction ability of 100%. The outstanding results obtained by this work provide the basis of a data matrix that could be used in real cases of arson to link a sample of unevaporated gasoline to its brand or refinery.     

The analysis of illicit methaqualone containing preparations by gas chromatography-mass spectrometry for forensic purposes

A validated gas chromatographic-mass spectrometric method for quantitative analysis of methaqualone (MTQ) in illicit preparations is reported. The method proved to have a coefficient of variation of below 5%. Four batches of seized tablets, two pairs with similar imprints, were analyzed. It was found that the average MTQ concentration in all four batches of tablets differed significantly (p = 0.01) rendering it impossible to conclude that, on the basis of MTQ concentration alone, the batches with a similar logo originated from the same manufacturer or manufacturing batch. Conversely, it can be said that in this case, the four batches originated from either different clandestine laboratories or manufacturing batches.     

Nanomanipulation‐Coupled Nanospray Mass Spectrometry Applied to the Extraction and Analysis of Trace Analytes Found on Fibers*

Abstract: This article presents the novel instrumentation of nanomanipulation coupled to nanospray ionization‐mass spectrometry, which is used to directly probe trace analytes found on individual fibers. The low detection limits and sample volumes associated with nanospray ionization‐mass spectrometry make it the ideal instrument to implement for trace analysis. Nanospray ionization‐mass spectrometry, coupled with the nanomanipulator, allows for the direct probing of trace particulates on fibers. The technique is demonstrated by dissolving an electrostatic particle of cocaine from a fiber, collecting the analyte solution in a nanospray tip, and transferring the tip directly to the mass spectrometer to complete analysis. The utility of this technique is evident through the minimal sample preparation and short analysis time. The use of nanomanipulation coupled to nanospray ionization‐mass spectrometry could improve on current trace particulate analysis by reducing both detection limits and sample size required to complete analysis.     

Temporal analysis of the cocaine metabolite benzoylecgonine in wastewater to estimate community drug use*

Abstract: Indirect estimation methods of cocaine consumption may not reflect the real extent of cocaine use. Another approach is sewage epidemiology. This direct approach is based on analysis of a stable cocaine metabolite, benzoylecgonine (BE), in wastewater. Influent to the Lubbock (Texas) Water Reclamation Plant was sampled twice a week to assess weekly variations in estimates of cocaine consumption over a 5‐month period. BE was extracted from influent wastewater samples using solid phase extraction and analyzed using gas chromatography/mass spectrometry. Measured concentrations of BE were converted to cocaine equivalents; the estimated average daily consumption of cocaine during the study period was 1152 ± 147 g. Based on BE concentrations and sewage epidemiology, higher cocaine consumption was observed on weekends compared to weekdays (p < 0.0003). This method was effective in monitoring BE in wastewater and could be used to complement survey data in estimating cocaine use at a local level.     

Thermal degradation analysis of amino acids in fingerprint residue by pyrolysis GC-MS to develop new latent fingerprint developing reagents

Conventional development of latent fingerprints is compromised when the prints are decomposed by extreme temperatures, such as those encountered when a weapon cartridge is fired, an improvised explosive device is detonated, and/or in arson cases. Understanding how these extreme temperatures alter the chemical and physical properties of latent fingerprint residue could aid in the discovery of a reagent that could effectively develop these decomposed fingerprints. To mimic scenarios where fingerprints may be exposed to high heat conditions, standards of the five most abundant amino acids in fingerprint residue as well as extracted fingerprint residue were pyrolized under controlled conditions. Compounds identified as pyrolytic decomposition products were 3,6-dimethylpiperazine-2,5-dione (from alanine), maleimide, and 2,5-furandione (from aspartic acid). The pyrograms and selected ion traces show these products to hold promise as indicators of decomposed fingerprint residues and, therefore, may serve as good candidate substrates for a developing reagent.     

A detailed mechanistic fragmentation analysis of methamphetamine and select regioisomers by GC/MS

A novel ring-substituted methamphetamine regioisomer, N,alpha,4-trimethyl phenmethylamine, was synthesized in order to study the validity of proposed structures for various mass spectrometry (MS)-derived peaks in a methamphetamine fragmentation pattern. While other research efforts have studied aspects of methamphetamine in detail, a full fragmentation study has not been reported previously. In addition to showing molecular structures represented by fragment peaks, mechanisms for selected processes are detailed. An empirically derived procedure to easily determine by simple spectral peak pattern recognition the geometry of dimethyl- or ethyl-substituted immonium ions (RRC = N+ RR) where m/z = 58 is outlined. These results are platform independent for electron ionization (EI) instruments, but have also proven to be helpful in explaining spectral peaks observed in spectra from ion trap systems. The spectrum for the synthesized methamphetamine regioisomer was accurately predicted using this methodology. While this approach is useful in some casework, the converse may be more useful: when an unexpected or unusual peak pattern arises in a spectrum, being able to analyze it to determine the structure of the molecule. This paper gives an analyst the means to begin such retro-synthetic analyses.     

Desorption electrospray tandem MS (DESI-MSMS) analysis of methyl centralite and ethyl centralite as gunshot residues on skin and other surfaces

Abstract:  A direct and sensitive method for the detection of methyl centralite (MC) and ethyl centralite (EC) as gunshot residues (GSRs) has been developed. This method uses desorption electrospray ionization (DESI)-tandem mass spectrometry and directly desorbs and detects analytes from surfaces without any sampling process. Typical transitions for MC and EC, m/z 241 to m/z 134 and m/z 269 to m/z 148, respectively, were used to improve the assay sensitivity. It has been shown that MC and EC can be detected on various surfaces, with detection limits of 5–70 pg/cm². Interferences, detection time after shooting and the number of times hands were washed after shooting were also evaluated. None of the materials interfered with the results and the detection window for organic GSRs was up to 12 h and hands could be washed at least six times. Further samples were analyzed to confirm the reliability of this method, and showed that it could discriminate shooters from nonshooters. This method should be of significance in forensic science, especially in analyzing GSRs, because of its simplicity, high throughput, and the direct detection of MC and EC on suspects' hands, clothes, and hair.     

Association of Ignitable Liquid Residues to Neat Ignitable Liquids in the Presence of Matrix Interferences Using Chemometric Procedures*,†

Abstract: In fire debris analysis, weathering of ignitable liquids and matrix interferences can make the identification of ignitable liquid residues (ILRs) difficult. An objective method was developed to associate ILRs with the corresponding neat liquid with discrimination from matrix interferences using principal components analysis (PCA) and Pearson product moment correlation (PPMC) coefficients. Six ignitable liquids (gasoline, diesel, ultra pure paraffin lamp oil, adhesive remover, torch fuel, paint thinner) were spiked onto carpet, which was burned, then extracted using passive headspace extraction, and analyzed by gas chromatography‐mass spectrometry. Both light and heavy burn conditions were investigated. In the PCA scores plot, ignitable liquids were discriminated based on alkane and aromatic content. All ILRs were successfully associated with the corresponding neat liquid using both PCA and PPMC coefficients, regardless of the extent of burning. The method developed in this research may make the association of ILRs with corresponding neat liquids more objective.     

The development of analytical and interpretational protocols to facilitate the provenance establishment of polycarbonate headlamp lens material

Despite the forensic significance of polycarbonate headlamp lenses, robust analytical protocols to facilitate their discrimination are scarce. In this study, laser ablation inductively coupled plasma mass spectrometry has been applied to the analysis of polycarbonate headlamp lenses with multivariate chemometrics techniques utilized to facilitate interpretation of the data. The analytical protocol involves the analysis of 46 analytes on material comprising the exterior surface of the lens. Using this data, it was found that although minor variation exists within a single headlamp lens, discrimination between lenses produced from a single manufacturing plant was still possible using iterative forward stepwise linear discriminant analysis processes. Discrimination between all headlamp lenses, with the exception of some lenses produced on the same day in a single plant, could be achieved using the analytical protocol. Furthermore, an interpretational protocol has been developed that has successfully classified all tested headlamp lens samples, within the discrimination limits of the analytical method.     

A review of the analysis of vegetable oil residues from fire debris samples: analytical scheme, interpretation of the results, and future needs

This paper reviews the literature on the analysis of vegetable (and animal) oil residues from fire debris samples. The examination sequence starts with the solvent extraction of the residues from the substrate. The extract is then prepared for instrumental analysis by derivatizing fatty acids (FAs) into fatty acid methyl esters. The analysis is then carried out by gas chromatography or gas chromatography-mass spectrometry. The interpretation of the results is a difficult operation seriously limited by a lack of research on the subject. The present data analysis scheme utilizes FA ratios to determine the presence of vegetable oils and their propensity to self-heat and possibly, to spontaneously ignite. Preliminary work has demonstrated that it is possible to detect chemical compounds specific to an oil that underwent spontaneous ignition. Guidelines to conduct future research in the analysis of vegetable oil residues from fire debris samples are also presented.