苯丙胺类气相色谱分析前衍生化条件筛选

目的筛选适合于苯丙胺类气相色谱分析的衍生化试剂,同时寻找最佳衍生化条件。方法选择乙酸酐、三氟乙酸酐、3,5-二硝基苯甲酰氯3种衍生化试剂,以气相色谱作为检测方法,比较在不同的衍生条件下(加热方式、微波功率、时间等)的衍生效果。结果获得3种不同衍生化产物的气相色谱分析结果,得出苯丙胺类经乙酸酐乙酰化,于微波Ⅱ档衍生反应3min,衍生化反应完全满意的结果。结论在适当条件下选用乙酸酐对苯丙胺类进行完全的衍生化反应,适用于该类毒品的定量分析。     

GC—MS／MS法检验生物检材中的无机氰化物

目的建立一种检验生物检材中无机氰化物的GCMS／MS方法。方法首先将生物检材中的无机氰化物在酸性条件下蒸馏出,用碱性溶液吸收后,氰离子在相转移催化剂作用下被五氟苄基溴（PFB-Br）衍生化,最后用GC-MS／MS法分析衍生化产物。结果衍生化产物PFB-CN的MS／MS质谱图特征性强,定性准确;在20-1500ng／g浓度范围内呈良好的线性关系（r＝0．998）,最低检测限为5ng／g,回收率为82．3％－98．6％。结论本方法简单实用,灵敏度高,准确可靠,适用于生物检材中无机氰化物的检验。     

用衍生化气相色谱法分析血液中巴比妥类安眠药

本文对衍生化气相色谱法检测人体液中巴比妥类安眠药进行了综述,列举了7种不同类型的衍生化反应,重点介绍了甲基化法的应用及其具体操作,是当今临床及法庭科学分析中较为先进、灵敏的检测技术。     

衍生化-液相色谱-质谱联用测定血中氟乙酸类杀鼠剂

目的建立血中氟乙酸类杀鼠剂衍生化-液相色谱-电喷雾离子阱质谱分析方法。方法血样经乙腈沉淀蛋白后离心,上清液中加入衍生化试剂α-溴苯乙酮和催化剂四丁基溴化铵,在60℃水浴中加热90min,衍生化产物直接进行液相色谱-电喷雾离子阱质谱联用分析。结果血中氟乙酸根浓度在0.15μg/mL～15.40μg/mL之间具有良好的线性关系,最低检出限为0.020μg/mL。结论本文建立的方法操作简便、灵敏、快速,适用于刑事案件中氟乙酸类杀鼠剂的快速检验。     

稻田水中莠去津及其代谢物的硅烷基衍生化-气质联用分析法

目的建立稻田水中莠去津及其代谢物去乙基莠去津（DEA）、去异丙基莠去津（DIA）和双去烃基莠去津（DDA）的灵敏的气质联用分析方法。方法稻田水样品用GDX501大孔树脂进行固相萃取,萃取物用N,O-双三甲硅烷基乙酰胺（BSA）进行三甲硅烷基衍生化,衍生物用选择离子监测的气质联用法分析。结果稻田水中4种分析物的检出限和测量限都不高于2ng/mL。结论该方法可用于刑事案件中莠去津毁坏稻田案件的检验。     

HPLC-UVD/FLD法测定血中氟乙酸类杀鼠剂

目的采用水相催化衍生化-液相色谱-紫外/荧光检测分析法,检测血中氟乙酸类杀鼠剂。方法血样经乙腈沉淀蛋白后,加入衍生化试剂4-溴甲基-7-甲氧基香豆素、催化剂四丁基溴化铵,在80℃水浴中衍生化反应120min,衍生产采用液相色谱-紫外/荧光检测分析。结果紫外检测法:氟乙酸根浓度在0.38～38.50μg/mL之间线性关系良好,最低检出限为0.10μg/mL;荧光检测法:氟乙酸根浓度在0.15～15.40μg/mL之间线性关系良好,最低检出限为0.050μg/mL。结论水相催化衍生化-液相色谱-紫外/荧光检测分析方法具有较好的灵敏度、准确性和精密度,可用于实际案例检测。     

五氟丙酰衍生化-气相色谱/质谱联用法分析尿液中7-氨基硝西泮

目的用五氟丙酰衍生化-气相色谱/质谱联用法分析尿液中硝西泮的主要代谢物7-氨基硝西泮。方法尿液经乙醚萃取后,用五氟丙酰酸酐(PFPA)进行衍生化,得到7-氨基硝西泮衍生化物的总离子流色谱图和质谱图。结果根据7-氨基硝西泮衍生化物色谱的保留时间和质谱中主要特征离子的质荷比进行定性分析;用7-氨基氟硝西泮做内标,以7-氨基硝西泮和内标衍生化物定量离子的色谱峰面积比与浓度的关系进行定量分析。结论用五氟丙酰衍生化-GC/MS分析尿液中硝西泮的主要代谢物7-氨基硝西泮的方法定性、定量灵敏准确,测定结果可应用于司法鉴定。     

离子色谱法检验亚硝酸盐

亚硝酸盐主要是指亚硝酸钠和亚硝酸钾,它们广泛用作化工原料及分析试剂等,常因误为食盐或面碱而中毒,也有见于投毒杀人。亚硝酸盐是一种血液毒,亚硝酸根离子能迅速使血红蛋白氧化成高铁血红蛋白而失去携氧功能,引起严重缺氧而窒息死亡。口服亚硝酸盐0·3g~0·5g可中毒,致死量为3g[1]。有人曾用比色法、示波极谱法[2]、高效液相色谱法[3]对亚硝酸盐进行分析,本文使用离子色谱法对亚硝酸盐进行定性定量分析。2004年7月9日,在广东省深圳市龙岗区同乐村发生一起法轮功练习者服用亚硝酸盐自杀事件,龙岗区公安分局提取了遗留在现场的怀疑为亚硝酸…     

GC/ECD检验生物检材中的氟乙酸钠

建立对生物检材中氟乙酸钠的GC/ECD检验方法。用PFBBr作衍生化试剂,对氟乙酸钠或氟乙酰胺中毒后脏器中的氯乙酸（氯乙酸钠）进行衍生化,GC/ECD和GC／MS的分析。在1ml血中添加lμg1080,其回收率为76．2％,RSD为3．07（n＝7）;在1g肝中添加2μg的1080其回收率为84．4％,RSD为1．87（n=5）。研究的方法经动物试验和大量中毒案件的验证,效果较好。该方法已在中毒案件的检验中广泛应用。     

离子色谱法检测土制硝铵氯化炸药爆炸残留物中的氯酸根

本文建立了离子色谱-抑制电导检测测定含有高浓度硝酸根的爆炸尘土中残留氯酸根的方法。使用高容量阴离子分析柱IonPac AS19，以KOH为流动相，梯度淋洗，氯酸根在8min左右出峰，15min之内完成常规离子的分析，方法的检测限为2．67ng／ml（S／N=3）。方法的线性范围为0．01～1000μg／ml，线性相关系数为0．9998。模拟样品中1μg／mlClO3^-的峰面积相对标准偏差为0．98％，峰高的相对标准偏差为0．66％。将此法应用于两起爆炸案的爆炸尘土样品测定，加标回收率在99％以上。对主要干扰物离子硝酸根的研究发现，即使3000μg／ml的硝酸根对低浓度氯酸根（几个ppm级）的测定也不存在干扰，确保了测定结果的准确性。     

Characterisation of gunshot residue from three ammunition types using suppressed anion exchange chromatography

Gunshot residue (GSR) is commonly analysed in forensic casework using either scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) or gas chromatography-mass spectrometry (GC-MS). Relatively little work has been reported on the post-discharge GSR content of non-metallic inorganic or low molecular weight organic anions to distinguish between different ammunition types. The development of an analytical method using suppressed micro-bore anion exchange chromatography (IC) is presented for the analysis of GSR. A hydroxide gradient was optimised for the separation of 19 forensically relevant organic and inorganic anions in <23min and sensitivities of the order of 0.12-3.52ng of anion detected for all species were achieved. Along with an optimised extraction procedure, this method was applied to the analysis of post-ignition residues from three selected ammunition types. By profiling and comparing the anionic content in each ammunition residue, the possibility to distinguish between each type using their anionic profiles and absolute weight is presented. The potential for interference is also discussed with respect to sample types which are typically problematic in the analysis of GSR using SEM-EDX and GC-MS. To the best of our knowledge this represents the first study on the analysis of inorganic anions in GSR using suppressed ion chromatography.     

Selective colorimetric determination of TNT partitioned between an alkaline solution and a strongly basic Dowex 1-X8 anion exchanger

The Meisenheimer anions formed from TNT in KOH solutions in alcohol or acetone were used in screening tests for TNT among possible nitro-explosives. The same reaction was used for the spectrophotometric assay of TNT in soil by CRREL (Cold Regions Research & Engineering Laboratory of the U.S. Army) method, also known as Jenkins' method, but the color stability was too dependent on the solution composition and the water tolerance was low, necessitating complete drying of soil samples (which may cause partial analyte decomposition) prior to analysis. This study reports the development of a colorimetric method based on the solid phase extraction (SPE) of the Meisenheimer anion formed from TNT and aqueous NaOH into a strongly basic anion exchange resin Dowex 1-X8 (OH(-) form). The orange-red color that developed both in the solid resin and solution phases was persistent for at least 1h. The resin was let to swell in alcohol, washed first with 1M aqueous NaOH, and then with H(2)O before use. To 5 mL of 4-400 ppm TNT solutions in 1:1 (v/v) acetone-water, 0.5 mL of 5% NaOH was added, diluted to 50 mL with 1:1 acetone-water, and the resulting solutions (containing the orange-red Meisenheimer anion of TNT) were agitated at room temperature with 0.9 g resin for < or =50 min. TNT exhibited a reasonably constant distribution coefficient between the resin and aqueous phases. The absorbance of the filtered solutions was measured against a reagent blank at 500nm. The TNT-loaded resins were regenerated with 1M HCl containing sodium sulfite. The calibration line of filtrate absorbance versus analytical concentration was linear over two orders of magnitude between 0.4 and 40 ppm TNT in final solution. Unlike Jenkins' method, the method was tolerant to 100-fold (by mass) of common soil anions like sulfate, nitrate, and chloride. The basic advantages of the developed colorimetric method over the similar CRREL/Jenkins' method may be summarized as color stability, water and common ion tolerance, lowering of the LOD, and widening of the linear range. As opposed to Jenkins' method, the charge-transfer bands characteristic to colorimetric detection were not obscured by the presence of water. The method is suitable for on-site applications, because the color developed in heterogenous solution was stabilized, and the method can be easily practiced with a portable colorimeter to large numbers of samples.     

Capillary ion electrophoresis of endogenous anions and anionic adulterants in human urine

Normal human urine contains many anions and cations. Ionic concentrations in urine have classically been determined by spectrophotometry of color reactions, flame emission spectrophotometry, atomic absorption spectrophotometry, high performance liquid chromatography, or potentiometry with ion-specific electrodes. Capillary ion electrophoresis (CIE) is a form of capillary electrophoresis which uses the differential electrophoretic mobility of ions to perform a separation of an ionic mixture. Various salts can be added to urine specimens to abnormally elevate ionic concentrations and interfere with either immunoassay urine drug screening procedures or gas chromatographic/mass spectrometric confirmation techniques. Application of CIE for the direct detection of endogenous anions and anionic adulterants in human urine specimens was the purpose of this investigation. CIE was performed using a Waters Quanta 4000 Capillary Electrophoresis System with either direct or indirect ultraviolet absorption detection at 254 nm. CIE of 30 random normal urine specimens and 21 urine specimens suspected of adulteration was performed. Duplicate aliquots were assayed by CIE and by colorimetric technique for nitrite. Sixteen specimens had elevated concentrations of nitrite and/or nitrate. The correlation coefficient between nitrite CIE and colorimetric results was 0.9895. Three specimens had detectable concentrations of chromate and were suspected of being adulterated with "Urine Luck," an adulterant found to contain chromate. Two specimens suspected of being adulterated with bleach were found to only contain chloride, sulfate, and phosphate. CIE is applicable to forensic analysis of urine anion concentrations. CIE can easily quantitate numerous endogenous anions and offers a method to detect and/or confirm anion adulteration of urine specimens.     

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.     

甲基苯丙胺对映异构体两种衍生化方法的比较分析

目的建立甲基苯丙胺毒品的对映异构体分析的优化方法。方法按文献方法用（S）-（＋）-a-甲氧基-a-（三氟甲基）苯基乙酰氯（MTPACl）对甲基苯丙胺直接衍生化和在碱性条件下用有机溶剂萃取后再用MTPACl衍生化（对文献方法优化）,分别对其衍生物采用全扫描形式进行GC-MS分析,比较其结果。结果优化方法的检测限低,峰型好,副反应少。文献方法的检测限是0.1ng,优化方法的检测限是0.001 6ng。结论优化方法用于甲基苯丙胺的对映体特征分析,结果更准确,实用性更强。     

离子色谱法检测全血中的亚硝酸盐及其代谢产物

目的建立全血中亚硝酸盐的离子色谱分析方法。方法将0.5mL全血和1mL水混合,用乙腈沉淀血液中的蛋白质后依次过C18柱、Ag柱和Na柱,用于去除其中的有机物和氯离子后进行离子色谱检测,并对蛋白沉淀溶剂、前处理柱等最佳实验条件进行考察。结果采用本文方法对空白添加全血进行检测,在色谱图上亚硝酸根离子及其氧化产物硝酸根离子的保留时间分别为10.02min、19.21min。选择乙腈作为蛋白沉淀剂,C18柱去除有机物,Ag柱去除氯离子,Na柱去除银离子。全血中亚硝酸根离子的检出限为0.05μg/mL,亚硝酸根和硝酸根的总回收率为95.9%~117.3%。结论本文方法简便,回收率好,灵敏度高,适用于中毒者血液中亚硝酸盐的检测。     

Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial

A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.     

Halogenated solvent interactions with N,N-dimethyltryptamine: formation of quaternary ammonium salts and their artificially induced rearrangements during analysis

The psychoactive properties of N,N-dimethyltryptamine (DMT) 1a are known to induce altered states of consciousness in humans. This particular attribute attracts great interest from a variety of scientific and also clandestine communities. Our recent research has confirmed that DMT reacts with dichloromethane (DCM), either as a result of work-up or storage to give a quaternary N-chloromethyl ammonium salt 2a. Furthermore, this was observed to undergo rearrangement during analysis using gas chromatography-mass spectrometry (GC-MS) with products including 3-(2-chloroethyl)indole 3 and 2-methyltetrahydro-beta-carboline 4 (2-Me-THBC). This study further investigates this so far unexplored area of solvent interactions by the exposure of DMT to other halogenated solvents including dibromomethane and 1,2-dichloroethane (DCE). The N-bromomethyl- and N-chloroethyl quaternary ammonium derivatives were subsequently characterised by ion trap GC-MS in electron and chemical ionisation tandem MS mode and by NMR spectroscopy. The DCE-derived derivative formed at least six rearrangement products in the total ion chromatogram. Identification of mass spectrometry generated by-products was verified by conventional or microwave-accelerated synthesis. The use of deuterated DCM and deuterated DMT 1b provided insights into the mechanism of the rearrangements. The presence of potentially characteristic marker molecules may allow the identification of solvents used during the manufacture of controlled substances, which is often neglected since these are considered inert.     

The determination of nicotine and sulfate in supermarket ground beef adulterated with Black Leaf 40

In December 2002, approximately 250 lbs. of ground beef was adulterated with nicotine sulfate by a supermarket employee and subsequently sold to the public. Soon afterward, reports of illness associated with ground beef purchased at a single store were identified. Authorities suspected the ground beef was tainted with Black Leaf 40, a banned pesticide containing approximately 40% nicotine as nicotine sulfate. Ground beef submitted to our laboratory was analyzed in concert by high performance liquid chromatography-ultraviolet detection (HPLC-UV), gas chromatography-mass spectrometry (GC-MS), and high performance anion exchange chromatography with suppressed conductivity detection. GC-MS was used to identify the samples that contained nicotine. The nicotine was confirmed and quantitated by HPLC-UV. The sulfate was identified and quantitated by high performance anion exchange chromatography with suppressed conductivity detection. Our analysis revealed that the raw tainted beef contained about 350 mg/kg nicotine free base, a potentially lethal dose of nicotine per serving for an adult. Additionally, we found elevated sulfate levels in the samples that tested positive for nicotine, providing evidence that nicotine sulfate was the probable adulterant.