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441.
The identification, analysis, and occurrence in U.S. automobile original finishes (1974-1989) of Nickel Titanate (yellow) and Chrome Titanate (yellow-orange) are described in this report. The titanate pigments are based on the rutile (titanium dioxide) structure and there are only minor differences between the infrared absorptions of rutile and the titanates. Titanate pigment absorptions in paint spectra can thus be easily mistaken for those of rutile. Each of the titanates, however, contains two elements in addition to titanium that can serve to distinguish them using elemental analyses. Fourier transform infrared (4000-220 cm(-1)) and X-ray fluorescence instruments were used in combination for the in situ analysis of the titanates. In addition to titanium, nickel, and antimony, the three main detectable elements comprising Nickel Titanate, all of the commercial products of this pigment that were examined also contained impurities of zirconium, niobium, and usually lead. These elements were also detected in most of the monocoats in which Nickel Titanate was identified, as well as in the Chrome Titanate pigments, and the zirconium to niobium ratio was found to exhibit a wide variation. Nickel Titanate is a relatively common pigment that was identified in nearly three dozen U.S. automobile yellow nonmetallic monocoats (1974-1989), while Chrome Titanate appears to have been used in only a few yellow and orange nonmetallic monocoats. The use of the titanate pigments likely increased after this time period as they were replacements for lead chromate pigments (last used in a U.S. automobile original finish in the early 1990s), and are more amenable for use in basecoat/clearcoat finishes than in monocoats. Minor distortions of the infrared absorptions of rutile, anatase, and the titanates obtained using accessories with diamond windows were noted, and their origins are discussed.  相似文献   
442.
A new type of heroin HCl seized in Australia was examined by stable isotope analysis. The final origin/process classification of these samples by chromatographic signature profiles of the impurity/manufacturing by-products was previously determined to be "unknown" by two independent national laboratories. Various drug enforcement authorities speculated that the heroin might be from a new region or new illicit process due to the unusual chromatographic impurity profiles that were present. Samples from 20 different kilogram packages were examined for isotopic content to determine if the samples fit isotopic patterns of known origins or if they were unique to any known origins. Authentic specimens from Southeast Asian (N=59), Southwest Asia (N=37), South America (N=104), and Mexico (N=21) we concomitantly examined for comparison purposes. Both continuous flow elemental analysis-isotope ratio mass spectrometry and gas chromatography-isotope ratio mass spectrometry techniques were utilized. Heroin samples were also converted to morphine, without apparent isotopic fractionation, utilizing methanolic HCl for gas chromatography-isotope ratio mass spectrometry. The Pong Su samples were found to be isotopically and isotopically/alkaloidally distinct from the known origin/process classifications of Southwest Asian, Southeast Asian, South American, and Mexican.  相似文献   
443.
This report describes the analytical characterization of 16 hashish samples confiscated in Italy. The samples were solvent extracted and subjected to GC-MS analysis for the separation and quantitation of the main cannabinoids. One of the analyzed samples was shown to contain extraneous compounds, identified as resin acids characteristic of colophony (rosin). Colophony is a natural resinous product obtained from various species of pine, spruce, and larch; it is a skin sensitizer and its fumes produce nonspecific irritation that can cause bronchial asthma. Similar adulterations of hashish have not been reported previously; therefore, at present there is no information about the effects of smoking colophony or a combination of hashish and colophony. It is presumed, however, that such a combination would be highly detrimental to the health of the user.  相似文献   
444.
ABSTRACT: The widespread availability of emulsion explosives for commercial blasting has inevitably lead to their diversion for criminal misuse. Present techniques for the characterization of emulsion explosives and their residues is generally based on the detection and identification of the oxidizer and the hydrocarbon components. Use of these components is problematic for residue identification because ammonium nitrate, waxes, and oils are relatively common in the urban environment and even their co-detection does not exclude them being sourced from materials other than explosives. The detection of the emulsifier component offers increased evidential value as certain emulsifiers used in explosive formulations are manufactured for that specific use, or have limited environmental distribution. In the current study liquid chromatography-mass spectrometry (LC-MS) was utilized for the characterization of two emulsifiers in common use; ethanolamine adducts of polyisobutylene succinic anhydride and sorbitol mono-oleate (SMO). The LC-MS technique enabled the detection of both emulsifiers in preblast samples; however, only SMO was detected in postblast residues. The analysis of the hydrocarbon component by gas chromatography-mass spectrometry was achieved in the same procedure.  相似文献   
445.
The estimation of serum strontium in rabbits before and after death by drowning, in soft or hard water, or by barbiturate intoxication is highly promising as a method in medicolegal practice. It not only diagnoses drowning but also indicates the type of drowning water. Atomic absorption spectrophotometry is a good method for the estimation.  相似文献   
446.
基体辅助激光解吸电离飞行时间质谱鉴别乌头的研究   总被引:2,自引:0,他引:2  
Pan AH  Liu J 《法医学杂志》2005,21(2):118-120
目的建立乌头类中药鉴别的基体辅助激光解吸电离飞行时间质谱方法。方法以DHB为基体,优化飞行时间质谱分析条件,对不同种类的乌头类中药进行飞行时间质谱分析,找出乌头类的指纹峰。结果通过比较炮制乌头与生乌头质谱指纹峰的差异,可作出乌头类是否经炮制的判断。结论基体辅助激光解吸电离飞行时间质谱用于乌头类中药的定性鉴别,分析方法灵敏、准确、快速。  相似文献   
447.
本文描述了鉴定常见毒物的 Kovǎts 保留指数系统。研究了各种因素(测量时间、柱操作温度,柱前压等)对保留指数值测定的影响,并在三根不同极性柱上,以不同温度,测定了四十种药物的保留指数;提出用 C—R3A 计算保留指数的 BASIC 程序。  相似文献   
448.
目的建立血液中1-(4-甲氧基苯基)哌嗪的液相色谱-三重四级杆/线性离子阱串联质谱(LC-QTrap-MS/MS)的快速检测方法。方法血液经乙腈沉淀蛋白后,振荡、离心、经微孔滤膜过滤后供仪器分析;选用Phenomenex Kinetx®5.0μm Biphenyl 100Å(100mm×2.1mm)分离,柱温40℃;以0.1%甲酸水溶液-乙腈为流动相,流速0.5mL/min,梯度洗脱5.5min;以多反应监测(MRM)-信息依赖性采集(IDA)-增强子离子扫描(EPI)-谱库检索的模式进行分析,外标-标准曲线法进行定量分析。结果血液中1-(4-甲氧基苯基)哌嗪的浓度在2~200ng/mL范围内呈现良好的线性关系,相关系数达到0.9984,回收率在87%以上,日内精密度在5%以下,日间精密度在10%以下,方法的检出限是0.8ng/mL,定量限是2ng/mL。结论该方法采用LC-QTrap-MS/MS和MRM-IDA-EPI模式,既保持与MRM相同的定量灵敏度,也能提供更为丰富的二级质谱碎片,使定性结果更加准确。方法简单快捷,专属性好,回收率高,重现性好,能够用于血液中1-(4-甲氧基苯基)哌嗪同时定性和定量分析。  相似文献   
449.
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。  相似文献   
450.
The proper governance of shale gas mining in the Karoo region of South Africa is important. With an estimated 390 trillion cubic feet of recoverable shale gas, large economic gains are possible. This may dramatically change the South African energy sector; in the United States, similar explorations have led to what pundits term the ‘shale gas revolution’. The development and production of shale gas hold economic advantages, but also potential environmental costs, thus the regulation of fracking activities is an important consideration as the development of shale gas in the Karoo progresses. This study reviews the regulations imposed in other countries as well as the current regulatory framework of South Africa. This article analyses these regulations in terms of the content of fracking fluid, seismic activity and the pricing regime. Effective regulation will be key to maximise a positive impact, should shale gas development continue.  相似文献   
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