Optimum methamphetamine profiling with sample preparation by solid-phase microextraction

Solid-phase microextraction (SPME) is a relatively new technique in which a small, polymer-coated fiber is employed to extract volatile and semivolatile organic compounds from the sealed headspace above a questioned sample. SPME, coupled with gas chromatography/mass spectrometry (GC/MS), was used to characterize impurities in illicit methamphetamine samples. Trace impurities present in a specimen were tentatively identified using mass-spectral databases and included 1,2-dimethyl-3-phenyl-aziridine (indicating synthesis via a halogenated ephedrine intermediate), ethyl vanillin (a flavoring compound), and caffeine (a stimulant used as cutting agent). The types and numbers of organic compounds sampled by SPME were compared with those collected by various solvent extraction protocols. In addition to unambiguously confirming the presence of methamphetamine, SPME-GC/MS analyses detected approximately 30 more organic analytes than were found by GC/MS following the ethyl acetate extraction method adopted by the United Nations International Drug Control Programme. SPME-GC/MS is a superior method for generating material "fingerprint" profiles in methamphetamine samples. The detection and characterization of increased points of comparison in drug samples provide more detailed chemical signatures for both intelligence and operational information.     

固相萃取-GC/MS法检测生物检材中的百草枯

目的采用固相萃取-气相色谱/质谱分析方法检测血液、尿液和脏器组织中的百草枯。方法人血液、尿液和猪肺组织样品经三氯乙酸去除蛋白后,取上清用十二烷基三甲基溴化铵和十二烷基硫酸钠处理过的C18小柱提取,提取物用硼氢化钠在碱性条件下还原,产物用气相色谱/质谱法分析,外标法定量。结果生物检材中百草枯回收率为78%～87%,最低检出限为0.1μg/mL,在0.5～1mg/mL范围内线性关系良好,可对实际案例检材进行定量检测。结论本文固相萃取-气相色谱/质谱分析方法能满足中毒生物检材检验及临床毒物检验需要。     

A Novel Forensic Tool for the Characterization and Comparison of Printing Ink Evidence: Development and Evaluation of a Searchable Database Using Data Fusion of Spectrochemical Methods

A searchable printing ink database was designed and validated as a tool to improve the chemical information gathered from the analysis of ink evidence. The database contains 319 samples from printing sources that represent some of the global diversity in toner, inkjet, offset, and intaglio inks. Five analytical methods were used to generate data to populate the searchable database including FTIR, SEM‐EDS, LA‐ICP‐MS, DART‐MS, and Py‐GC‐MS. The search algorithm based on partial least‐squares discriminant analysis generates a similarity “score” used for the association between similar samples. The performance of a particular analytical method to associate similar inks was found to be dependent on the ink type with LA‐ICP‐MS performing best, followed by SEM‐EDS and DART‐MS methods, while FTIR and Py‐GC‐MS were less useful in association but were still useful for classification purposes. Data fusion of data collected from two complementary methods (i.e., LA‐ICP‐MS and DART‐MS) improves the classification and association of similar inks.     

GC法和GC/MS法在地区毒品情报分析中的应用

目的探讨气相色谱法(GC)和气相色谱/质谱联用法(GC/MS)在地区毒品情报分析中的应用,并用于实际样品分析。方法采用GC/MS法定性分析毒品样品中的主成分、痕量杂质、掺假剂和稀释剂,并选择GC/FID法和内标标准曲线法定量分析上述各组分,通过定性和定量数据的统计和分析,推断该地区的毒品状况。结果用GC/MS定性分析、GC/FID定量分析,和数据的统计比对,获得了某省某年27起海洛因毒品大案样品主成分、痕量杂质、掺假剂和稀释剂组成及含量的特征,发现该省缴获的大宗海洛因毒品主要以掺假和稀释后的产品出现,且咖啡因和扑热息痛为两种主要的掺假剂和稀释剂。结论GC/MS和GC/FID法在地区毒品情报分析和打击毒品犯罪中可以发挥重要作用。     

Cannabinoids determination in oral fluid by SPME–GC/MS and UHPLC–MS/MS and its application on suspected drivers

The confirmation of Δ9-tetrahydrocannabinol (THC) in oral fluid (OF) is an important issue for assessing Driving Under the Influence of Drugs (DUID). The aim of this research was to develop a highly sensitive method with minimal sample pre-treatment suitable for the analysis of small OF volumes (100 μL) for the confirmation of cannabinoids in DUID cases. Two methods were compared for the confirmation of THC in residual OF samples, obtained from a preliminary on-site screening with commercial devices. An ultra high performance LC–MS (UHPLC–MS/MS) method and an SPME–GC/MS method were hence developed. 100 μL of the residual mixture OF/preservative buffer or neat OF was simply added to 10 μL of THC-D3 (1 μg/mL) and submitted to the two different analyses: A — direct injection of 10 μL in UHPLC–MS/MS in positive electrospray ionisation (ESI) mode and B — sampling for 30 min with SPME (100 μm polydimethylsiloxane or PDMS fibre) and direct injection by desorption of the fibre in the GC injection port.The lowest limit of detection (LLOD) of THC was 2 ng/mL in UHPLC–MS/MS and 0.5 ng/mL in SPME–GC/MS. In addition, cannabidiol (CBD) and cannabinol (CBN) could be detected in GC/MS equipment at 2 ng/mL, whilst in UHPLC–MS/MS the LLOD was 20 ng/mL.Both methods were applied to 70 samples coming from roadside tests. By SPME–GC/MS analysis, THC was confirmed in 42 samples, whilst CBD was detected in 21 of them, along with CBN in 14 samples. THC concentrations ranged from traces below the lowest limit of quantification or LLOQ (2 ng/mL) up to 690 ng/mL.     

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.     

GC和GC/MS技术在毒品来源推断中的应用

目的应用气相色谱(GC)和气相色谱/质谱联用(GC/MS)技术,定性、定量分析毒品案例,推断毒品来源。方法采用GC/MS法定性分析毒品样品中的主成分、痕量杂质、掺假剂和稀释剂,并选择GC/FID和外标法定量分析上述各组分,通过定性和定量数据的统计比对,并用SPSS10.0数据统计分析软件对分组结果进行验证,推断毒品样品之间来源的区别与联系。结果用GC/MS定性分析、GC/FID定量分析和SPSS10.0数据统计分析软件将12个案件的毒品按来源分成7组,其中1、6、7、11号样品和10A、10B样品分成两组,2、3、5、9号样品各成一组,4号和8号样品分成一组。上述12起案件的毒品来源分析和比对结果,经送检部门反馈的破案信息证明,与案件的真实情况十分吻合。结论应用GC/MS、GC/FID技术分析毒品,可准确推断毒品来源。     

Chromatographic and spectroscopic profiles of Cannabis of different origins: Part I

High-resolution capillary gas chromatography with flame ionization detection and mass spectrometry (GC and GC/MS) and high-performance liquid chromatography (HPLC) were used to establish complex chemical profiles (chemical signatures) of Cannabis samples of known origin. Over 100 compounds could be differentiated, including noncannabinoids (terpenes, alkanes) as well as minor and major cannabinoids and their acids. A characteristic peak pattern was found within a limited number of specimens of identical origin. Correlation studies on the basis of peak area ratios [A(x)/A(i.s.)] showed the feasibility of tracing Cannabis chemically to its country of origin. Several forensic science applications for the chromatographic and spectroscopic profiles of confiscated Cannabis samples are discussed, such as detection of additives (phencyclidine), differentiation of chemotypes, and monitoring of tetrahydrocannabinol (THC) potency.     

生物检材中巴比妥类药物固相萃取及分析方法

目的建立生物检材中巴比妥类药物的提取净化和定性定量分析方法；方法应用固相萃取法提取生物检材中巴比妥类药物，比较了巴比妥类药物固相萃取的最佳pH值、固相吸附柱等提取条件；结果确定了巴比妥类药物的GC／NPD线性范围和GC／MS检出限；结论该方法实用，提取率高，杂质干扰少，为实际案件中巴比妥类药物的提取净化和定性定量分析提供了方法和依据。     

尿样中苯骈二氮杂Zhu类药物筛选分析研究

目的建立尿样中苯骈二氮杂类药物两种筛选分析方法.方法用GC/ECD、GC/MS直接测定苯骈二氮杂类药物原体和GC/ECD、GC/MS测定1,4-苯骈二氮杂类药物的酸水解产物苯甲酮同系物.结果GC/ECD直接测定苯骈二氮杂类药物方法,大部分药物的回收率为60%～90%,线性范围为20～200ng/ml尿,线性相关系数大于0.99,最低检出限达0.5ng/ml～10ng/ml.结论所建两种方法各有其特点又可相互补充,已成功地应用于司法鉴定实践.     

Benzoylecgonine (cocaine metabolite) detection in hair samples of jail detainees using radioimmunoassay (RIA) and gas chromatography/mass spectrometry (GC/MS)

Benzoylecgonine (BE) was detected in hair samples using nonproprietary extraction methodology and modifications of well-established radioimmunoassay (RIA) screening/quantitative gas chromatography/mass spectrometry (GC/MS) confirmation procedures. Samples collected anonymously from a population of 48 jail detainees weighed between 5.3 and 61.2 mg. All of the 22 hair samples which had RIA results indicating the presence of BE or immunologically similar substances above a cutoff amount of 1.25 ng/sample (50 ng/mL) were confirmed by GC/MS. Several varieties of hair color and texture were tested, although in each general category there were samples which contained BE as well as other samples which did not reveal detectable amounts of BE. The range of concentrations in 22 hair extracts that screened positive were 0.26 to 18 ng/mg hair as determined by GC/MS. In comparison with other reports of cocaine-related substances in hair, these data show consistent concentrations.     

Detection of gamma-hydroxybutyrate (GHB) in beverages

OBJECTIVE: To establish an analytical method for the determination of GHB in beverages using GC/MS and LC/MS/MS. METHODS: After beverage samples with GHB-d6 as the internal standard were extracted with ethyl acetate, then the extracts were derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), at last the derivateized extracts analyzed by gas chromatography- mass spectrometry. After beverage samples with GHB-d6 as the internal standard were diluted by mobile phase then directly analyzed by LC/MS/MS. Results The limit of detection was 0.2 microg/mL and both relative standard deviations for between-day and within-day assays were < 8.54% in GC/MS. The limit of detection was 2 microg/mL and both relative standard deviations for between-day and within-day assays were <8.62% in LC/MS/MS. Conclusion These methods of qualitative and quantitative analysis were found to be sensitive, accurate, rapid and suitable for the forensic toxicology to test of GHB in real cases.     

Confirmation of Syva enzyme multiple immunoassay technique (EMIT) d.a.u. and Roche Abuscreen radioimmunoassay (RIA) (125I) urine cannabinoid immunoassays by gas chromatographic/mass spectrometric (GC/MS) and bonded-phase adsorption/thin-layer chromatographic (BPA-TLC) methods

Thirty human urines screened positive by the Syva enzyme multiple immunoassay technique (EMIT) d.a.u. urine cannabinoid assay were also positive for the major marijuana urinary metabolite 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) when assayed by gas chromatographic/mass spectrometric (GC/MS) and a noninstrumental qualitative bonded-phase adsorption/thin-layer chromatographic (BPA-TLC) technique. The noninstrumental BPA-TLC procedure was the simpler of the two techniques to perform and interpret. Assay of these same samples by the Roche Abuscreen radioimmunoassay (RIA) for cannabinoids (125I) revealed that reliance on the 100-ng/mL equivalent positive calibrator yielded a high incidence of false negative results (10 out of 30). The performance of these same 4 assays on 30 true negatives also was evaluated. All samples were negative for cannabinoids by EMIT and RIA, and for THC-COOH by BPA-TLC. GC/MS assay, however, detected spurious low levels of approximately 5-ng/mL THC-COOH in two instances. Because of this, a reliability level of 10 ng/mL was set for the routine quantitative confirmation of THC-COOH by the GC/MS method.     

Effect of Gas Chromatography Temperature Program on the Association and Discrimination of Diesel Samples*†

Abstract: Five diesel samples were analyzed by gas chromatography–mass spectrometry (GC‐MS) using six GC temperature programs, aiming to investigate the effect of temperature program on association and discrimination of the samples. Temperature programs varied by ramp rate and incorporated one‐ or two‐step temperature ramps. Pearson product moment correlation coefficients and principal components analysis were used to evaluate differences in discrimination among the diesel samples afforded by each temperature program, based on the total ion chromatogram (TIC) and selected extracted ion profiles (EIPs). Association of diesel replicates and discrimination among samples based on the TIC and aromatic EIP were similar for all temperature programs based on scores plots. The alkane EIP was not useful in discriminating samples regardless of temperature program, because of similar alkane content of the diesel samples. The association and discrimination of diesel samples was largely unaffected by temperature programs that incorporated one‐ or two‐step temperature ramps.     

兔体内三唑仑及其代谢物的检测

目的不同方法检测三唑仑及代谢物α-羟基三唑仑，为其及时、准确的检测提供科学证据和最优方法。方法用GC／NPD、GC／MS、MS／MS、GC／ECD对兔体内三唑仑及代谢物α-羟基三唑仑进行检测。结果GC／ECD法最易检测出三唑仑及其代谢物。结论兔胃及内容物、尿液中容易检测到三唑仑及其代谢物；运用酶水解后，检测率最高；GC／ECD检测三唑仑及其代谢物的灵敏度最高。     

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.     

A contribution to the chemical profiling of 3,4-methylenedioxymethamphetamine (MDMA) tablets

A profiling method for the identification of impurities found in seized 3,4-methylenedioxymethamphetamine (MDMA) tablets is presented. Impurities of interest are extracted from an alkaline solution (pH 12.8) by diethyl ether and submitted to gas chromatography (GC)-mass spectrometry (MS) analyses. Identification of impurities is performed by electron impact ionization (Ei) mass spectrometry and confirmation by positive chemical ionization (Ci+) MS or, when possible, MS/MS (MS(2)). Repeat extractions of the same sample give an average relative standard deviation (R.S.D.) of less than 8% within the same day and 15% between days (results were obtained after normalization by the sum of peak areas, each one being acquired by selected ion monitoring (SIM)). Possible application toward batch comparison of samples is discussed. Chromatographic profiles are compared using the cosine function for evaluating similarity and/or dissimilarity among exhibits.     

GC/MS法测定人体血液和肾、肝组织中的丙泊酚

目的 采用气相色谱/质谱法检测人体血液和肾、肝组织中的丙泊酚.方法 心血和肾、肝组织中的丙泊酚经环己烷提取,采用气相色谱/质谱法,丙泊酚选择m/z 163、178,内标百里香酚选择m/z 150、135进行测定;并考察方法专属性、线性范围、定量线与检出限、回收率与精密度.结果 丙泊酚的保留时间为8.17min,与内标百里香酚分离良好;其在心血和肾、肝组织中的检测浓度线性关系良好,r值均大于0.992,最低检测质量浓度分别为0.05 μg/mL、0.10μg/g及0.05 μg/g,方法回收率90％ ～ 110％,日内、日间RSD均小于7％.结论 本文方法简便、灵敏、快速,其准确度、精密度和回收率均可满足生物检材中丙泊酚浓度的测定,可在相关研究及实践中选用.     

体内海洛因代谢产物的分析研究

本文介绍了从海洛因成瘾者尿中提取净化和定性定量分析海洛因主要代谢产物单乙酰吗啡和吗啡的方法．阳性尿以乙基吗啡为内标．水解后液－液提取或液－固提取，经衍生化后采用ＧＣ／ＭＳ，ＧＣ／ＦＩＤ，ＧＣ／ＮＰＤ法分析，方法简便、准确、灵敏、重现性好．应用本法对八十余例吸毒成瘾者尿样进行测定，取得了令人满意的结果．     

The Characterization of 3,4-Dimethylmethcathinone (3,4-DMMC)

Analogs and derivatives of traditional illicit drugs are ever increasing in variety and creativity. Staying abreast of the new developments is a constant challenge for every forensic laboratory. Recently, a seizure from Australian Customs Service presented our laboratory with the designer cathinone 3,4-dimethylmethcathinone (3,4-DMMC). Gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and ultraviolet (UV) spectrophotometry were employed to analyze the spectroscopic characteristics of this cathinone. As an analog, 3,4-DMMC exhibits similar if not identical IR and UV profiles to mephedrone (4-MMC) and methcathinone; however, the retention time from GC is unique as expected, and the electron impact fragmentation pattern is consistent with the fragmentation pattern of other cathinones. The chemical shifts of the carbons and hydrogens were assigned by both one- and two-dimensional NMR techniques, while the molecular weight was confirmed by LC/MS.