红外光谱相似的汽车中涂漆的鉴别分析

目的 应用裂解气相色谱-质谱法结合聚类分析,鉴别9个红外光谱相似的汽车中涂漆样品.方法 从漆片中分离、提取出中涂漆样品,用裂解气相色谱-质谱检测并结合红外光谱检测,结果采用SPSS 19统计软件（美国IBM公司）对裂解数据进行聚类分析.结果 裂解气相色谱质谱的检测结果经聚类分析处理,9个中涂漆样品按其裂解图谱的差异可分为4类;而结合红外光谱的检验结果,最终可将5类中涂漆样品一一区分.结论 在汽车中涂漆的鉴别中,裂解气相色谱-质谱检测是对红外光谱检测的重要补充,能够有效地提高对中涂漆的鉴别能力.     

裂解气相色谱-质谱对百元假币红色墨迹的初步研究

目的 初步建立鉴别百元假币的方法.方法 分别各取适量5张百元假币红色墨迹,应用裂解气相色谱-质谱法(Py-GC/MS)直接检测.结果 通过分析裂解产物,获得百元假币墨迹成膜物主要成分信息.结论 该研究结果可对目前社会上发现的5种百元假币红色墨迹的成膜物进行分析.     

新精神活性物质Eutylone的鉴定

目的 建立基于傅里叶变换红外光谱（Fourier transform infrared spectroscopy,FTIR）、气相色谱-四极杆飞行时间质谱（gas chromatography-quadrupole time-of-flight mass spectrometry,GC-QTOF-MS）、超高效液相色谱-线性离子阱-四极杆-轨道阱质谱（ultra-high performance liquid chromatography-linear ion trap quadrupole-orbitrap mass spectrometry,UPLC-LTQ-Orbitrap MS）和核磁共振氢谱（1H-nuclear magnetic resonance spectroscopy,1H-NMR）技术联合鉴定未知样品的方法。方法 采用傅里叶变换红外光谱仪直接检测未知样品;未知样品用含内标SKF525A的甲醇溶液溶解,上清液供GC-QTOF-MS和UPLC-LTQOrbitrap MS检测;未知样品用氘代甲醇溶液溶解后供1H-NMR检测。结果 未知样品获得的红外光谱特征吸收峰为1 6...     

气/质联用和气相色谱-NPD法分析唾液中哌替啶

目的建立唾液中哌替啶的提取方法以及气相色谱-质谱和气相色谱-NPD分析方法。方法实验家兔静脉注射哌替啶,于注射后15~600min之间的10个时间点收集唾液样品;样本加入内标物利多卡因,采用有机溶剂萃取后,进行气相色谱-质谱联用(GC/MS)定性分析、气相色谱-NPD定量分析唾液中哌替啶浓度。并对不同p H条件和不同有机溶剂萃取剂以及方法学进行考察。结果在p H12条件下使用二氯甲烷萃取唾液中哌替啶效果较好。唾液中哌替啶气相色谱-NPD分析方法线性检测范围为2.0~100.0μg/m L,相关系数0.995 0,最低检出限为2.0μg/m L,回收率范围98.80%~114.72%,日内和日间精密度均小于2.88%。结论建立的唾液中哌替啶气/质联用和气相色谱-NPD分析方法,可用于哌替啶中毒与滥用的快速检验鉴定。     

气相色谱-质谱联用法同时测定8种合成大麻素

目的采用气相色谱质谱联用(GC/MS)法检测8种合成大麻素,并对方法进行评价。方法甲醇提取及超声处理样本后,采用GC/MS法检测JWH-203、JWH-250、RCS-4、JWH-018、JWH-019、JWH-122、AM-2201和JWH-210等8种合成大麻素,并对色谱柱、初始温度、升温速率等条件进行了优化。结果使用中等极性的DB-17MS色谱柱(30m×0.32mm×0.25μm),采用起始温度200℃,以20℃/min速率升温至280℃,以10℃/min速率升温至300℃的条件进行检测。8种合成大麻素能够很好的分离,检测限达到20μg/m L;应用该方法对未知样品进行了检测,并对各类合成大麻可能的质谱碎裂途径进行分析。结论本文方法具有分析简便、快速、灵敏的特点,可以用于实际案件的检测。     

基于气相色谱质谱法的不同极性圆珠笔墨迹的比较分析

目的采用气相色谱质谱法(GC/MS)比较分析不同极性圆珠笔墨迹的挥发性溶剂组成,探讨圆珠笔墨水溶剂成分的差异性。方法对书写墨迹采用甲醇超声提取离心后取上清液进样分析。气相色谱条件:HP-INNOWax色谱柱,分流比:3:1,程序升温:80℃保持1 min,15℃/min升温至150℃,保持1 min,6℃/min升温至250℃,保持5 min。质谱条件:EI离子源,溶剂延迟:3min,扫描范围为:29-350 amu。结果不同极性圆珠笔墨迹溶剂成分均为醇类物质,水性和中性圆珠笔墨水溶剂多为乙二醇、丙二醇和丙三醇等中等极性的脂肪醇,油性圆珠笔墨水多采用苯甲醇、苯氧乙醇等弱极性芳香醇作为常用有机溶剂。结论 GC-MS对圆珠笔墨迹的不同溶剂组成进行有效区分与识别,方法可行、结果可靠。     

N,N-二烯丙基-5-甲氧基色胺片剂的GC/MS检验

目的 建立N,N-二烯丙基-5-甲氧基色胺的气相色谱-质谱(GC/MS)定性分析方法。方法 未知片剂样品用甲醇超声溶解,吸取上清液采用气相色谱-质谱(GC/MS)联用仪检测。结果 测得未知组分(tR=10.45min)的质谱特征碎片峰(m/z)信息为110.1(基峰)、270.1、174.1、160.1、145.0、130.1和117.1。查阅资料并对该组分的质谱图谱进行解析,鉴定为N,N-二烯丙基-5-甲氧基色胺,属于色胺类化合物。结论 该方法简单,准确,可用于N,N-二烯丙基-5-甲氧基色胺的鉴定。     

3,4-亚甲二氧基甲卡西酮的鉴定

目的 建立基于傅里叶变换红外光谱(FTIR)、气相色谱-质谱(GC-MS)结合高分辨质谱技术联合鉴定未知样品的方法.方法 未知样品采用红外专用取样器直接检测;甲醇溶解后采用GC-MS和组合型高分辨质谱检测,以MDMA为内标物.结果 未知样品获得的红外光谱特征吸收峰为1679(C=O键),1603,1502,1453,1423,1259,1121,1090,1035,930,887,838,768,742和717cm-1,质谱特征碎片峰(m/z)为58.1,91.0,120.9,149.0和207.0,测得的精确质量数[M+H]+为208.0966.经信息分析未知样品鉴定为3,4-亚甲二氧基甲卡西酮,该物质属于新型化学合成卡西酮类精神活性物质,已经列入部分欧盟国家的管制药物目录.结论 本方法可用于3,4-亚甲二氧基甲卡西酮的鉴定.     

5F-UR-144的热不稳定性研究

目的利用气相色谱-质谱法(GC-MS)、液相色谱-四级杆-飞行时间质谱(LC-Q-TOF/MS)和核磁共振光谱法(NMR)研究合成大麻素5F-UR-144遇热分解的具体变化情况。方法对照品用无水乙醇定容稀释后,经GC-MS和LC-Q-TOF/MS检测得到对应的色谱图和质谱图;对照品分别于常温和280℃密封加热后用无水乙醇定容稀释,经LC-Q-TOF/MS和NMR检测得到对应的质谱图、¹H和¹³C核磁共振波谱;对照品分别于常温逐步提升至300℃密封加热后用无水乙醇定容稀释,经LC-Q-TOF/MS检测得到对应的色谱图。结果5F-UR-144在高温下会开环产生新的物质;5F-UR-144从130℃开始分解,随着温度升高分解程度提升,240℃时分解率达到98%;随着温度继续升高,超过260℃,分解产物会碳化。结论基于5F-UR-144的热不稳定性,在检测时应考虑若通过烫食方式吸食5F-UR-144,其进入人体的成分会发生变化;气相色谱或气相色谱-质谱法不适合定量检测5F-UR-144。     

气相色谱/质谱检验合成大麻素K3中AKB48

目的建立较为快速准确的合成大麻素K3中AKB48的气相色谱/质谱检验方法。方法对进样口温度、初始柱温、柱流速及质谱采样率等4项色谱及质谱实验参数进行考察优化。结果 GC/MS检验合成大麻素K3中AKB48的优化条件为:进样口温度280℃,柱初始温度80℃,柱流速为2.0ml/min,质谱采样率为2。结论该方法具有快速、准确、灵敏等优点,可用于K3中AKB48的定性检验鉴定。     

裂解气相色谱-质谱法分析鉴别轮胎胎面胶

目的对裂解气相色谱-质谱法分析橡胶的裂解条件进行优化,研究利用橡胶特征裂解产物鉴别轮胎胎面胶。方法采用裂解气相色谱-质谱法,确定对NR、BR、SBR的裂解条件及其特征裂解产物,然后根据特征裂解产物及其相对含量并结合聚类分析,对38种轮胎胎面胶进行区分鉴别。结果确定了裂解温度590℃、裂解时间15s及三种橡胶的特征裂解产物;将38个轮胎胎面胶样品的主体成分归为4类,其中NR类5个、SBR类12个、NR/BR并用类5个、NR/SBR并用类16个,且能够对大部分并用类轮胎胎面胶进行鉴别。结论通过优化裂解条件,裂解产物重复性好,特征裂解产物明显,能够确定轮胎胎面胶的主体成分类别并能对大多数并用类轮胎胎面胶样品进行区分鉴别。     

Identification of pressure-sensitive adhesive polypropylene tape

Identification of colorless, transparent, pressure-sensitive adhesive polypropylene tape (PP tape) was performed using infrared absorption spectrometry (IR) and pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to determine the pressure-sensitive adhesive. Twenty different products of colorless, transparent PP tapes were examined in this study, and the results of analysis of IR spectra and Py-GC/MS were classified into twelve groups. In addition, the tapes were classified into 14 groups on the basis of IR measurement of release agent present in the backside. The results indicate that colorless, transparent PP tapes can be distinguished in terms of manufacturer, thereby demonstrating that this method of identifying colorless, transparent PP tape is effective. Moreover, the method was applied to the analysis of an actual forensic sample.     

Direct identification of various copper phthalocyanine pigments in automotive paints and paint smears by laser desorption ionization mass spectrometry

Direct identification of copper phthalocyanine (CuPc) and chlorinated CuPcs in paints for discrimination between blue automobile paints by means of laser desorption mass spectrometry (LDMS) in the absence of a matrix is reported. The models consisted of eight commercially available CuPc pigments applied to a piece of plain white coating paper. The relationship between the peak intensity at m/z 575 of the CuPc, the number of pulsed laser shots, and laser power was compared to optimize laser abrasion. LDMS analysis of the model paints demonstrated that all characteristic components of the CuPc pigments in the paint films were in good agreement with those in the powder pigments. Further, the chlorinated CuPcs in the paint films could be distinguished. A quantity of 42 blue paint films, representing the paints used for painting Japanese domestic trucks, was examined by LDMS analysis. Results indicate that the paints can be classified into four categories based on the chlorinated CuPc components of the paints. Therefore, LDMS spectra of CuPc pigments would be useful for the identification of paints in forensic investigations. Herein, we report the successful identification of the CuPcs in a paint smear on the frame of a bicycle damaged in a hit-and-run accident, using the LDMS spectra.     

Forensic applications of pyrolysis capillary gas chromatography

A simple system of pyrolysis capillary gas chromatography has been used to improve discrimination and long-term reproducibility in the analysis of polymers particularly alkyd based paints typically encountered in forensic casework. This involved the coupling of a Pye Curie-point pyrolyser to the inlet port of a capillary gas chromatograph operated in the splitless mode. Examples of pyrograms demonstrating improved differentiation of alkyd paints, and also examples of other architectural and automotive paints, automobile rubbers, adhesives, polyurethane foams and fibres are shown.     

Analysis and discrimination of architectural paint samples via a population study

This study involved the comparative analysis and discrimination of 964 architectural paint samples collected in the United States and Canada. The samples were evaluated to determine the extent to which randomly collected architectural finishes can be discriminated following standard operating protocols for paint analysis. The study also provides a basis for assessing the significance of a result in which a pair or group are undifferentiated. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with both backscatter electron imaging (BSI) and energy dispersive spectroscopy (EDS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). To assess the layer characteristics (e.g., number, color, sequence, thickness), stereomicroscopy was used with FTIR and/or SEM as needed. The use of visual and microscopic evaluations in concert with FTIR resulted in 42 undifferentiated pairs, a discrimination of 99.99%. Adding SEM and Py-GC/MS analysis resulted in further discrimination of 31 pairs, resulting in eleven undiscriminated pairs of samples. At the conclusion of the study, samples that remained undifferentiated proved to originate from the same source. Therefore, no random pairs were indistinguishable at the conclusion of all examinations.     

Discriminating red spray paints by optical microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence

Red spray paints from different European suppliers were characterised to determine the discriminating power of a sequence of analysing techniques. A total of 51 red spray paints were analysed with the help of three techniques: (1) optical microscopy, (2) Fourier transform infrared spectrometry and (3) X-ray fluorescence. Infrared spectra were classified according to binder type, filler and pigment composition and a searchable spectral library was created. Due to the difference in the elemental composition of spray paints, a further discrimination was possible. The microscopic analysis was not taken into consideration for classification purposes. The structure of the substrate under a paint coating strongly affects the surface characteristics of this spray paint. Together with the spectral library, a database of information of spray paints was build.     

HS-SPME-GC/MS法检测尿液及毛发中苯丙胺类毒品

目的采用顶空固相微萃取（HS-SPME）、GC/MS分析方法,对生物样品中苯丙胺（AM）、甲基苯丙胺（MAM）、3,4-亚甲二氧基苯丙胺（MDA）和3,4-亚甲二氧基甲基苯丙胺（MDMA）4种苯丙胺类毒品进行定性定量分析。方法在碱性和饱和盐处理状态下,采用100μm聚二甲基硅氧烷（PDMS）萃取纤维,于顶空瓶中进行生物样品AM、MAM、MDA、MDMA 4种毒品萃取,以2-甲基苯乙胺为内标,经气-质联用选择离子检测（GC/MS/SIM）模式进行定性定量分析。对HS-SPME条件优化,对方法的精密度、准确度和检出限进行测定。结果 AM、MAM、MDA、MDMA 4种毒品尿液中的最低检出限为5ng/mL,毛发中的最低检出限为0.5ng/mg。尿液中线性关系范围为0.05μg/mL~5μg/mL,r〉0.991,回收率为82%~108%,RSD为2.6%~6.1%（n=5）;毛发中线性关系范围为5ng/mg~500ng/mg,r〉0.992,回收率为80%~113%,RSD（%）为1.4%~6.8%（n=5）。结论 HS-SPME-GC/MS各项定量参数符合分析要求。该方法简单、灵活、经济、快速、无溶剂,适用于生物检材中该类毒品的分析。     

Analysis and discrimination of electrical tapes: Part I. Adhesives

This study involved the comparative analysis and discrimination of 90 electrical tape adhesives. The objectives included the evaluation of the ability of individual techniques to discriminate samples and the assessment of the ability of the techniques combined to distinguish samples. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Stereomicroscopy, to assess adhesive colors of black, clear/colorless, and clear adhesives with brown tint, resulted in a discrimination of 53%. FTIR analysis yielded eight distinct groups with a discrimination of 67%. Py-GC/MS analysis resulted in 16 groups with a discrimination of 83%. These analyses confirmed and further subdivided the FTIR groups. SEM/EDS resulted in five separate groups at 17% discrimination, increasing the overall discrimination to above 85%.     

Potential of soil organic matter molecular chemistry determined by pyrolysis-gas chromatography/mass spectrometry for forensic investigations

Wetlands near urban centers may be more isolated areas and can be chosen for the disposal of bodies or used as a crime scene. The predominant soils in these areas usually have a high content of organic matter (OM), classified as Histosols. Soil organic matter (SOM) is composed of many different compounds that can be identified by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The study aimed to use Py-GC/MS to classify small amounts of organic soil in a forensic context. We sampled Histosols from five representative sites of Curitiba, Brazil. The molecular composition of the samples was determined by byPy-GC/MS. The factor analysis was carried out, and the factor scores showed a clear differentiation between the sites. Compounds indicative of relatively fresh plant material was separated from more recalcitrant and charred material. Py-GC/MS has the potential to be a useful tool to study the composition of SOM in Histosols to track the trace sample collected from a crime suspect.