Positive and negative ion mass spectrometry of benzophenones, the acid-hydrolysis products of benzodiazepines

Positive electron impact (EI), positive chemical ionization (CI), and negative CI mass spectra of 14 benzophenones are presented. In the positive EI mode, intense molecular peaks appeared for most compounds; some other peaks due to splitting at both sides of the carbonyl group also appeared. In the positive CI mode, [M + 1]+ quasi-molecular ions together with [M + C2H5]+ peaks were observed for all compounds; some fragment peaks were common to those in the positive EI mode. In the negative CI mode, the spectra were much simpler than those in the positive EI or CI mode. In the 1 Torr negative CI mode, some spectra showed only single molecular anions; in the 0.01 Torr negative CI mode, halogen or nitro peaks appeared in addition to the molecular anions. An extraction procedure for benzophenones from human urine and plasma after heating in strong acid, and their separation by gas chromatography (GC) are also presented to serve for their actual identification by GC/mass spectrometry.     

Determination of methadone in urine using ion trap GC/MS in positive ion chemical ionization mode

Methadone is a potent analgesic and sedative. It is widely used in the treatment of heroin addiction and is often encountered in forensic specimens. In electron impact (EI) gas chromatography/mass spectrometry (GC/MS) mode, methadone produces predominantly a m/z 72 ion, which is not sufficiently characteristic for identification. Determination of the molecular ion, which can be achieved using chemical ionization (CI) provides diagnostic information and better identification of the drug. This paper describes the development of a positive ion CI GC/MS procedure, using a liquid reagent gas and ion trap instrumentation, for the determination of methadone and its metabolites in urine. CI generally produces a single molecular ion spectrum, but optimization of the reagent gas parameters increases the fragmentation of the molecule, allowing determination of ion ratios if required. The procedure is sensitive, diagnostic and is currently in routine use in our laboratory.     

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.     

Positive and negative ion mass spectrometry of tricyclic antidepressants

Positive electron impact (EI), positive chemical ionization (CI), and negative CI mass spectra of eight tricyclic antidepressants are presented. In the positive EI mode, peak(s) at m/z 193 and/or 195, which corresponded to the tricyclic nucleus, appeared for five compounds; a peak at m/z 58 was common to compounds having a gamma-dimethylaminopropyl group as their side chain. Molecular ions appeared for all compounds though they were very small in some compounds in the positive EI mode. In the positive CI mode, [M + H]+ quasi-molecular peaks appeared together with [M + C2H5]+ peaks in five compounds; the ion at m/z 196, which corresponded to the tricyclic nucleus also appeared in five compounds. In the negative CI mode with 1 Torr chamber pressure, [M - 1]- quasi-molecular ions were observed for all compounds except for lofepramine; [M + 43]- anions, which probably corresponded to [M + C3H4]-, appeared in five compounds; strong [M + Cl]- ions appeared in carpipramine and clocapramine. The anions due to the tricyclic nucleus also appeared in this mode. In the negative CI mode at low pressure (0.01 Torr), the spectra were generally similar to those in the 1 Torr negative CI mode. However, the cluster anions never appeared at the low pressure. Some data on extraction for some antidepressants from human urine and plasma, and their separation by gas chromatography, are also presented.     

Detection of methamphetamine and amphetamine in a single human hair by gas chromatography/chemical ionization mass spectrometry

A detailed procedure of an extremely sensitive method for quantitation of methamphetamine and amphetamine in human hair by gas chromatography (GC)/chemical ionization (CI) mass spectrometry (MS) is presented. N-methylbenzylamine was used as an internal standard. The samples, after extraction with an organic solvent, were derivatized with trifluoroacetic anhydride before the GC/MS analysis. Quantitation was made with quasi-molecular ions of the derivatives by selected ion monitoring in the CI mode. The detection limit was about 10 pg in an injected volume. The high sensitivity enabled us to measure both stimulants in a single human hair in actual cases.     

氟草烟的GC／MS检验

目的本文研究GC/MS测定氟草烟的检测方法。方法采用GC/EI/MS、GC/CI/MS结合分析,确定氟草烟的色谱峰,并得到氟草烟的质谱图。结果通过质谱解析确认氟草烟的质谱图。结论本方法结果准确可靠。     

尿中三唑苯二氮(艹卓)及其主要代谢物,1-羟甲基三唑苯二氮(艹卓)的EI/CI/MS鉴定

本文在综合文献的基础上,建立了尿中三唑苯二氮(艹卓)及其主要代谢物的鉴定方法。本法以20ml尿样,在PH为9时,用乙醚提取。提取物用无水硫酸钠脱水,K、D、浓缩到0.5ml,固体进样杆直接进行EI/CI/MS分析;质谱分析在Finnigan Mat 1020 GC/MS/DS仪上进行。EI、CI源,甲烷作反应气,源室压力0.35吒。2ul样品由固体进样杆进样,其温度程序:初温60℃,以120℃/min速率升温到350℃。所建立的分析方法快速、灵敏,口服给药量为0.5mg时,可检出尿中1—羟甲基三唑苯二氮(艹卓)。     

Positive and negative ion mass spectrometry of antiepileptic hydantoins and their analogs

Positive ion electron impact (PIEI), positive ion chemical ionization (PICI), and negative ion chemical ionization (NICI) mass spectra of seven compounds of hydantoins and their analogs are presented; their probable fragmentation modes are also presented. In the PIEI mode, intensities of molecular ions differed according to different compounds. Cleavage at outsides of both carbonyl groups was commonly observed for all compounds. In the PICI mode, all compounds showed [M + 1]+ quasi-molecular ions constituting the base peaks. In the NICI mode, [M - 1]- quasi-molecular anions were the base peaks except for trimethadione and paramethadione. All negative spectra showed anions at m/z 42 due to [NCO]-; these peaks seem useful for screening of antiepileptics. An extraction procedure for the anti-epileptics from human urine or plasma, and their separation by gas chromatography (GC), are also presented to serve for their actual identification by GC/mass spectrometry.     

Analysis of drugs of abuse in hair by automated solid-phase extraction, GC/EI/MS and GC ion trap/CI/MS

In our laboratory, analysis of human hair for the detection of drugs of abuse was first performed in 1995. Initially, requests for hair analysis were few, and it is only since 1997 that these analyses have become routine. As demand grew, we developed an automatic solid-phase extraction method; the use of a robot ASPEC allowed us to drop certain fastidious manipulations, and to treat a large number of samples at a time. This method is described, along with analysis by gas-chromatography-mass spectrometry (GC/MS) in selected ion monitoring mode (SIM), for the following drugs: codeine, 6-monoacetylmorphine (6-MAM), morphine, cocaine, methadone, ecstasy (MDMA) and Eve (MDE). This requires prior derivatization with propionic anhydride. The different validation parameters, linearity, repeatability, recovery and detection limits are described, as well as the application of this method to some real cases. Analysis of these cases is also performed by an ion trap GC/MS in chemical ionization mode (GC/IT/CI/MS) in order to demonstrate the usefulness of this technique as a complement to routine analysis. Analysis by GC/IT/CI/MS indeed avoids the risk of false-positive results by the identification of metabolites.     

GC‐MS and GC‐MS/MS in PCI Mode Determination of Mescaline in Peyote Tea and in Biological Matrices

Peyote, a cactus containing the hallucinogen mescaline, is used to induce altered states of consciousness in religious ceremonies or for recreational purpose. This study reports a case of an underage boy suspected of mescaline abuse. For this purpose, we analyzed a dark green liquid sample found in the bedroom of the boy whose urine and hair samples were collected shortly after the drink was found. A method by gas chromatography‐mass spectrometry tandem mass spectrometry (GC‐MS/MS) in positive chemical ionization mode was developed and validated in terms of linearity, specificity, accuracy, and sensitivity for mescaline determination at the low concentrations present in hair. GC‐MS analysis of the liquid identified mescaline, while urine was negative; GC‐MS/MS segmental hair analysis identified mescaline in the proximal segment (root to 2 cm), while the distal segments were negative. Although peyote was uncommonly encountered, its use was confirmed by segmental hair analysis that can provide long‐term information about drugs use.     

Detection limits for GC/MS analysis of organic explosives

Method detection limits are determined and compared for analysis of liquid injections of organic explosives and related compounds by gas chromatography-mass spectroscopy utilizing electron impact (EI), negative ion chemical ionization (NICI), and positive ion chemical ionization (PICI) detection methods. Detection limits were rigorously determined for a series of dinitrotoluenes, trinitrotoluene, two nitroester explosives, and one nitramine explosive. The detection limits are lower by NICI than by EI or PICI for all explosives examined, with the exception of RDX. The lowest detection limit for RDX was achieved in the PICI ionization mode. Judicious choice of the appropriate ionization mode can enhance selectivity and significantly lower detection limits. Major ions are reported for each analyte in EI, PICI, and NICI detection modes.     

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.     

Attempted murder with pancuronium

A nurse was accused of attempting to murder her anesthesiologist husband on two occasions by administering to him a neuromuscular blocking agent. In both episodes, urine specimens were obtained from the victim shortly after the suspected assaults. The samples were initially tested fluorometrically using Rose Bengal dye as a pairing agent. Both were presumptively positive for pancuronium. Confirmation of these results was achieved by pairing the drug with potassium iodide, extracting the complex, and submitting the extract to thin-layer chromatography (TLC) cleanup, elution at the appropriate retardation factor (Rf), and, finally, gas chromatography/mass spectrometry (GC/MS) analysis in the selected-ion monitoring mode. The two quaternary amines of pancuronium appear to undergo pyrolytic N-demethylation in the injection port to yield an entity amenable to capillary column gas chromatography. The mass spectrum of the compound consists of a base peak of m/z 322, with additional fragments of 292, 323, 338, and 397 m/z, each of which was monitored. The confirmed positive findings were instrumental in adjudicating the case.     

Application of LC−QTOF/MS for the validation and determination of organic explosive residues on Ionscan® swabs

The identification and confirmation of trace explosive residues along with potential precursors and degradation products require a comprehensive laboratory analysis procedure. This study presents the determination of organic explosives consisting of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), 2,4,6,N-tetranitro-N-methylaniline (Tetryl), 1,3,5-trinitrobenzene (1,3,5-TNB) and pentaerythritol tetranitrate (PETN) by a high-resolution liquid chromatography quadrupole time-of-flight mass spectrometry (LC−QTOF/MS). The qualitative information including retention time, collision energy, precursor ions, and characteristic fragmentation pattern of each explosive were collected using an atmospheric pressure chemical ionization (APCI) in negative ion mode. The separation efficiency among five compounds was greatly achieved in this study. Four real explosive samples consisting of TNT, RDX, PETN and Tetryl and 12 Ionscan® quality control swabs from the Royal Thai Army were also tested to validate and verify the viability of the GC–MS method used to validate results from an Ionscan® system. The results showed that LC−QTOF/MS is a powerful technique for the identification and confirmation of thermally unstable organic explosives on Ionscan® swabs compared to a conventional GC−MS technique.     

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.     

Validity testing of commercial urine cocaine metabolite assays: IV. Evaluation of the EMIT d.a.u. cocaine metabolite assay in a quantitative mode for detection of cocaine metabolite

The EMIT d.a.u. cocaine metabolite assay (EMIT dau) was evaluated in a quantitative mode for analysis of clinical specimens obtained after controlled cocaine administration to human subjects. The quantitative results showed high concordance with those of gas chromatography/mass spectrometry (GC/MS) assays of the same specimens for benzoylecgonine, and no false positive or false negative results were obtained. The evaluation also included analysis of standardized solutions containing benzoylecgonine, cocaine, and other cocaine metabolites and isomers. The EMIT dau antibody demonstrated high selectivity for benzoylecgonine. The precision was somewhat less than that reported earlier for other commercial cocaine metabolite immunoassays. Quantitation of initial screening results from EMIT dau testing can serve as a useful guide for confirmation by GC/MS in forensic science urine testing.     

LC-MS/MS同时分析尿液中15种安眠镇静药物及其代谢物

目的建立尿液中15种常见安眠镇静药物及代谢物的液相色谱-串联质谱分析方法。方法尿液经酶水解、固相萃取后,用C18液相柱分离,以含甲酸铵和甲酸的水、乙腈为流动相梯度洗脱,质谱采用电喷雾电离（ESI）-正负离子模式同时扫描,采用二级质谱多反应监测（MRM）模式检测目标化合物。结果以化合物的保留时间、两对母离子/子离子对定性,尿中常见安眠镇静药物的检测限为0.01～0.5ng/mL（ESI＋）和10ng/mL（ESI-）;相关系数r在0.994以上;日内及日间精密度均在18%以下;绝对回收率在64.80%～116.20%之间。结论方法快速、灵敏、简便、可靠,能同时分析尿液中的15种安眠镇静药物及其代谢物。     

GC/MS法联合分析生物检材中的尼美舒利、二氧丙嗪

目的建立生物检材中尼美舒利、二氧丙嗪的GC/MS检验方法。方法采用浸取法提取,GC/MS定性检验,内标法选择离子检测（SIM）模式定量检验。结果最低回收率为69%,尼美舒利的线性相关系数为0.998,克咳敏的线性相关系数为0.9973。结论该方法操作简便快速,提取率高,可用于实际案件中尼美舒利、二氧丙嗪的检验。     

苯二氮卓类新精神活性物质去氯依替唑仑的定性检验方法研究

目的建立苯二氮卓类新精神活性物质去氯依替唑仑的气相色谱-质谱(GC-MS)和超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)定性检验方法。方法未知样品用甲醇和水提取,取上清液,采用GC-MS和UPLC-Q-TOF MS进行分析。结果经GC-MS检测,保留时间为17.73 min的未知组分的质谱碎片主要特征离子峰有m/z 279,308,239,252,225,77,126。经UPLC-Q-TOF MS检测,保留时间为4.781 min的未知组分的准分子离子峰为309.1173,碰撞诱导解离(CID)模式下二级质谱主要离子有m/z 280.0776,255.0952,240.0719,225.0604,206.0748。经缴获毒品分析科学工作组(Scientific Working Group for the Analysis of Seized Drugs,SWGDRUG)分析谱库检索和文献查询获得的信息资料进行比对,鉴定为去氯依替唑仑。结论该方法具有分析简便、快速的特点,可以用于实际案件的检测。     

GC‐MS and IR Studies on the Six Ring Regioisomeric Dimethoxyphenylpiperazines (DOMePPs)

A number of N‐substituted piperazines have been described as drugs of abuse in recent years. This new drug category includes several series of aromatic ring substituted phenylpiperazines. The wide variety of available precursors makes regioisomerism a significant issue in these totally synthetic compounds. In this study, a complete series of regioisomeric dimethoxyphenylpiperazines were synthesized and evaluated using GC‐MS and FT‐IR. The EI mass spectra show fragments characteristic of both the dimethoxyphenyl and the piperazine portions of the molecules including the dimethoxyphenylaziridinium cation (m/z 180) and dimethoxyphenyl cation (m/z 137). The ion at m/z 56 for the C₃H₆N⁺ fragment is characteristic of the piperazine ring and was observed in all the spectra. The perfluoroacyl derivatives were resolved by GC, and their mass spectra showed some differences in relative abundance of ions. FTIR provides direct confirmatory data for differentiation between the regioisomeric dimethoxyphenylpiperazines, and GC separation was accomplished on an Rtx‐200 phase.