毛细管电泳技术分析炸药残留物中无机离子

目的　建立炸药残留物中无机离子的毛细管电泳检测方法。方法　运用缓冲溶液使无机离子在毛细管电泳中达到分离 ,采用紫外间接检测法分析。结果　该方法可从爆炸残留物中准确检测出无机阴离子 (Cl- 、SO2 - 4、NO- 2 、NO- 3、ClO- 3和ClO- 4离子 )和无机阳离子 (NH 4、K 、Na 和Mg2 离子 )。结论　操作方法简便快捷 ,检材用量少 ,检测极限可达ng/ml级 ,分析结果满意     

离子色谱法用于新精神活性物质盐型测定

目的建立新精神活性物质(new psychoactive substance,NPS)盐型测定的离子色谱分析方法。方法建立离子色谱法分析NPS样品中6种有机酸根离子(乙酸根、酒石酸根、马来酸根、草酸根、富马酸根、柠檬酸根)和5种无机阴离子(氟离子、氯离子、硝酸根离子、硫酸根离子、磷酸根离子)的定性和定量分析方法。采用该方法对222份缴获NPS样品(103份含合成大麻素类,81份含卡西酮类,44份含苯乙胺类,12份含色胺类,7份含苯环利啶类,6份含哌嗪类,2份含氨基茚满类,26份含芬太尼类,43份含其他类)中的盐型进行分析。结果各阴离子在相应的线性范围内线性良好,相关系数(r)均大于0.999,检出限为0.01～0.05 mg/L,定量限为0.1～0.5 mg/L。合成大麻素类样品中,除(4-苄基哌嗪-1-基)[1-(5-氟戊基)-1H-吲哚-3-基]甲酮(5F-BEPIRAPIM)为盐酸盐外,其余102份均为碱型;81份卡西酮类、44份苯乙胺类、7份苯环利啶类、2份氨基茚满类样品的盐型均为盐酸盐;色胺类样品的盐型包括碱型、盐酸盐、富马酸盐、草酸盐4种;哌嗪类样品的盐型包括盐酸盐和碱型2种;芬太尼类和其他类样品的盐型包括碱型、盐酸盐、柠檬酸盐3种。结论采用离子色谱法对NPS样品的盐型进行分析,简单、准确、高效,使得NPS定性和定量结论更加科学、严谨。     

离子色谱法在法医毒物分析中的应用(一起服盐酸自杀死亡案例的检验)

<正> 离子色谱技术(简称IC)是继气相色谱(简称GC)、液相色谱(简称HPLC)之后,于70年代才发展起来的一种新型色谱分析技术。这一分析技术自问世以来发展迅速,其在能源、环境,食品、医疗卫生、水文地质、化工冶金、半导体、电镀、造纸、纺织和生产质量控制等方面已得到广泛应用,能测定的离子和化合物,包括无机阴离子、无机阳离子和有机化合物三大类已达数百种。     

X射线衍射法（XRD）检验无机炸药初探

目的建立XRD检验无机炸药成分的方法。方法利用X射线衍射仪对单体硝酸铵及其混合炸药、黑火药等进行检验分析。结果准确确定各炸药样品物质组成。结论该方法能够直接给出无机炸药中各组分的分子式,是无机炸药定性分析的理想的方法,并且操作快速简便,无损样品。     

HPLC-MS/MS方法检验血液中可待因

目的 采用HPLC-MS/MS方法对血液中可待因进行定性、定量检验.方法 以Clean Screen DAU混合阳离子交换固相萃取柱提取血样,应用HPLC色谱法分离,MS/MS检测分析.结果 该方法回收率高于70％,线性范围0.01～2 μg/mL,检测限0.1ng(S/N≥3).结论 本文方法快速、灵敏、准确,可用于血液中可待因的定性、定量分析检验.     

用分时选择离子质谱法一次检测多种药物

目的建立一种能避免生物样品中杂质的干扰,一次排查多种药、毒物,准确、灵敏度高的检验方法。方法应用分时选择离子质谱法,对常见毒物进行检验研究。结果在样品经简单净化处理的情况下,以分时选择离子质谱法检测,一次检测多个毒物(最多32个),定性、定量准确,灵敏度50～100ng/ml,经与全扫描质谱法进行比较,灵敏度提高2～3个数量级。结论该方法能有效提高排查毒物检测灵敏度,适用于常见毒物的排查检验。     

大麻概况及其气相分析方法综述

随着大麻走私的日益猖獗,对大麻进行快速准确的定性定量分析,为司法部门量刑提供准确可靠的依据显得尤为重要。本文对大麻的化学成分、检材种类、滥用方式进行介绍,并对气相色谱分析方法中涉及的检材提取方法、内标物、色谱柱和质谱图等进行综述。     

百草枯的HPLC分析

目前,投毒案件的对象已经不仅限于动物(包括人),而是转向多方面、多样化,1998年5月,笔者遇到一起用除草剂百草枯拓杀死16亩小麦的案件,通过本案,笔者建立了定性、定量检测百草枯的方法.百草枯(paraquat)又名克无踪、离子对草快,化学结构名称为1,1 -二甲基-4,4’-联吡啶阳离子,分子式Cl_(12)H_(14)N_2(阳离子)=187.6,结构式为:(?)     

生物样品中三氯杀螨醇的气相色谱分析

本文建立了用GC/ECD法,在3根色谱柱上定性、定量分析三氯杀螨醇农药的方法,其线性范围在0～6ng/μl。同时建立了生物样品中提取、净化三氯杀螨醇的方法,操作步骤简单快速,能够满足气相色谱分析。添加20μg的回收率为77.1％。该方法已应用于实际办案,效果良好。     

PTV-GC/MS结合程序计算法对120余种药物毒物的快速筛选

近年来,涉及化学药物、毒物、毒品等案件逐年增多,需要对常见药物进行快速定性和定量分析。在实际案件检验中,由于受诸多因素的影响,同样采用GC/MS方法,结果却差别很大,尤其对于无明确目标生物样品(如血、尿)的样品经提取浓缩并GC/MS全扫描分析后,所得到的总离子色谱图含有大量     

Highly sensitive screening method for nitroaromatic, nitramine and nitrate ester explosives by high performance liquid chromatography-atmospheric pressure ionization-mass spectrometry (HPLC-API-MS) in forensic applications

A highly sensitive screening method based on high performance liquid chromatography atmospheric pressure ionization mass spectrometry (HPLC-API-MS) has been developed for the analysis of 21 nitroaromatic, nitramine and nitrate ester explosives, which include the explosives most commonly encountered in forensic science. Two atmospheric pressure ionization (API) methods, atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI), and various experimental conditions have been applied to allow for the detection of all 21 explosive compounds. The limit of detection (LOD) in the full-scan mode has been found to be 0.012-1.2 ng on column for the screening of most explosives investigated. For nitrobenzene, an LOD of 10 ng was found with the APCI method in the negative mode. Although the detection of nitrobenzene, 2-, 3-, and 4-nitrotoluene is hindered by the difficult ionization of these compounds, we have found that by forming an adduct with glycine, LOD values in the range of 3-16 ng on column can be achieved. Compared with previous screening methods with thermospray ionization, the API method has distinct advantages, including simplicity and stability of the method applied, an extended screening range and a low detection limit for the explosives studied.     

Rapid screening of selected organic explosives by high performance liquid chromatography using reversed-phase monolithic columns

This study presents the rapid screening of various high grade explosives by high performance liquid chromatography (HPLC) with monolithic stationary phases. Two gradient methods were developed, the first for quantitative analysis of eleven explosives: HMX; RDX; Tetryl; TNT; 2,3-DNT; 2,6-DNT; 3,4-DNT; 2-NT; 3-NT; 4-NT; and PETN in under 14 min. The second method separated seven explosives in under two min and is suitable for rapid screening to determine the presence of specific and/or class of explosive. The rapid screening methods were successfully applied to soils spiked with known amounts of target explosives. This technology showed excellent potential for forensic explosives detection and analysis.     

Trace analysis of peroxide explosives by high performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (HPLC-APCI-MS/MS) for forensic applications

An HPLC-APCI-MS(/MS) method for the (trace) analysis of the most commonly encountered peroxide explosives, hexamethylenetriperoxidediamine (HMTD) and triacetonetriperoxide (TATP), has been developed. With this method, HMTD and TATP have been analyzed in the same run. (Pseudo-)molecular ions of these peroxides have been obtained as base peak under the same condition. A series of product ions was produced from these pseudo-molecular ions ([HMTD - 1]+ and [TATP + NH4]+) in the MS/MS analysis. We also pioneered in showing that a TATP molecular ion [TATP + H]+ can be observed with HPLC-MS/MS. The limit of detection for HMTD and TATP was 0.26 and 3.3 ng, respectively, on column by HPLC-MS in the Full Scan mode and 0.08 and 0.8, respectively, by HPLC-APCI-MS/MS in Selected Reaction Monitoring (single mass unit) mode. The method presented has been applied successfully for the identification of peroxides in the bulk solid state (powder sample), as well as in post-blast extracts originating from a forensic case. For the post-blast extracts, the use of tandem MS has been shown clearly to be of crucial importance for the identification and detection of the peroxide explosives.     

The discrimination of automotive clear coats by pyrolysis-gas chromatography/mass spectrometry and comparison of samples by a chromatogram library software

Identification particles used for the purpose of the post-blast identification of explosives have a coding system based on the combination of metal oxides and their various concentrations. These materials are composed of the polymeric matrix, iron powder (ferromagnetic properties), UV light active dyestuff and various metal oxides in a various ratios. A suitable analytical method has to be used for an accurate characterization of these metal components in the particles in order to find the required information, i.e. to determine the place and the year of production and as the case may be, also the production batch of misused explosives. In this work, the method of microwave digestion and flame atomic absorption spectrometry (F-AAS) was developed for an accurate determination of Zn, Mg, Cu and Pb in a few novel types of identification particles and applied to their characterization. When using specific sample treatment (digestion with a mixture of nitric acid with hydrochloric or hydrofluoric acid), the 3 sigma limits of detection (LODs) for the determination of Zn, Mg, Cu and Pb in 5mg original samples were 1.9, 0.2, 1.3 and 2.4 mg g(-1), respectively. The signal suppression due to the presence of HNO3+HCl or HNO3+HF was observed for Zn; therefore, the calibration solutions had to be prepared exactly with the same acids as those used for the sample mineralization. The determination of Mg, Cu and Pb was free of interferences; hence a simple calibration curve method could be adopted for attaining accurate results. The accuracy was checked by comparison of the results with those obtained by means of independent inductively coupled plasma optical emission spectrometry (ICP-OES). Good precision values, as relative standard deviation, in the range of 1-5% were obtained. A total number of 71 samples was analysed and classified by multivariate methods to prove the suitability of the procedure proposed for the purpose of the identification of explosives.     

Selective detection of trace nitroaromatic, nitramine, and nitrate ester explosive residues using a three-step fluorimetric sensing process: a tandem turn-off, turn-on sensor

Detection of trace quantities of explosive residues plays a key role in military, civilian, and counter-terrorism applications. To advance explosives sensor technology, current methods will need to become cheaper and portable while maintaining sensitivity and selectivity. The detection of common explosives including trinitrotoluene (TNT), cyclotrimethylenetrinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, 2,4,6-trinitrophenyl-N-methylnitramine, and trinitroglycerin may be carried out using a three-step process combining "turn-off" and "turn-on" fluorimetric sensing. This process first detects nitroaromatic explosives by their quenching of green luminescence of polymetalloles (lambda em approximately 400-510 nm). The second step places down a thin film of 2,3-diaminonaphthalene (DAN) while "erasing" the polymetallole luminescence. The final step completes the reaction of the nitramines and/or nitrate esters with DAN resulting in the formation of a blue luminescent traizole complex (lambda(em) = 450 nm) providing a "turn-on" response for nitramine and nitrate ester-based explosives. Detection limits as low as 2 ng are observed. Solid-state detection of production line explosives demonstrates the applicability of this method to real world situations. This method offers a sensitive and selective detection process for a diverse group of the most common high explosives used in military and terrorist applications today.     

The Analysis of Black Powder Substitutes Containing Ascorbic Acid by Ion Chromatography/Mass Spectrometry*†

Abstract: Black powder substitutes containing ascorbic acid are a group of low explosives that utilize ascorbic acid as the fuel. The analysis of these powders is complicated by the degradation of ascorbic acid which occurs rapidly in solution and may also occur as the powder ages. Aqueous extracts of both intact powders and postblast residues were analyzed by an existing ion chromatography/mass spectrometry (IC/MS) method used at the Bureau of Alcohol, Tobacco, Firearms and Explosives. Results have shown that while ascorbic acid itself is not detected in this method, its diagnostic degradation products (threonic acid, monohydrated diketogulonic acid, and oxalic acid) can be identified. In addition, anions from the inorganic oxidizers (perchlorate and nitrate) and combustion products such as chloride, chlorate, and nitrite, can be identified within the same experiment. While this IC/MS method shows promise, future modifications are necessary because of limitations in identifying threonate in postblast residues, as well as coeluting compounds observed in postblast residues.     

Visual detection of trace nitroaromatic explosive residue using photoluminescent metallole-containing polymers

The detection of trace explosives is important for forensic, military, and homeland security applications. Detection of widely used nitroaromatic explosives (trinitrotoluene [TNT], 2,4-dinitrotoluene [DNT], picric acid [PA]) was carried out using photoluminescent metallole-containing polymers. The method of detection is through the quenching of fluorescence of thin films of the polymer, prepared by spray coating organic solutions of the polymer, by the explosive analyte. Visual quenching of luminescence (lambda(em) approximately 400-510 nm) in the presence of the explosive is seen immediately upon illumination with near-UV light (lambda(ex)=360 nm). Detection limits were observed to be as low as 5 ng for TNT, 20 ng for DNT, and 5 ng for PA. In addition, experiments with normal production line explosives and their components show that this technology is also able to detect composition B, Pyrodex, and nitromethane. This method offers a convenient and sensitive method of detection of trace nitroaromatic explosive residue.     

Analysis of forensic soil samples via high-performance liquid chromatography and ion chromatography

Traditional forensic soil comparisons are performed via physical and/or chemical examinations of color, texture, and mineral content, leaving any organic- or water-soluble fractions unexamined. This study uses high-performance liquid chromatography (HPLC) and ion chromatography (IC) to assess the qualitative and quantitative variation in these fractions of soil. Soil samples (n=120) were collected over the course of 3 weeks from urban, suburban, and rural locations in and around Lansing, MI. Additional samples from six of these locations (two urban, two suburban, and two rural) were collected once a week for 10 weeks for temporal analysis. Nine additional samples, equally spaced over a 1 m(2) grid, from these same six locations were collected for spatial analyses. Qualitative and quantitative analysis of the resultant chromatograms separated the 120 samples into 10 groups by HPLC and 23 groups by IC. This study shows that using HPLC and IC to analyze the organic- and water-soluble fractions of soil can successfully discriminate samples. Quantitative analysis of the results eliminates some false inclusions by providing further differentiation of samples. The results of this study indicate that adding HPLC and IC analyses to traditional forensic soil analysis schemes can improve overall sample differentiation. The methods used in this study were also able to detect both qualitative and quantitative variations in soil over a relatively small geographic area. This demonstration of soil heterogeneity underscores the importance of the collection of a representative known sample population when assessing a forensic soil comparison. Significant temporal variation was also demonstrated over the course of 10 weeks of sampling; however, samples were found to be consistent over shorter periods of time. Baseline levels of inorganic anions were determined via IC; these levels may be useful in assessing the significance of anions detected in soil from cases involving low explosives.     

Determination of elemental sulfur in explosives and explosive residues by gas chromatography-mass spectrometry

A new method for the positive identification of elemental sulfur in explosives and explosive residues is developed. Following a carbon disulfide wash of explosives or explosive residues, a sample of the extracted material is injected onto a gas chromatography (GC) column, then analyzed via mass-selective (MS) detection. A positive identification of elemental sulfur is based on both retention time and fragmentation pattern. The GC-MS method is demonstrated to be useful in detecting and positively identifying elemental sulfur from both burned and unburned explosive mixtures. With a detection limit of 2.5 ng (2.5 x 10(-9) grams) of elemental sulfur on the column, it is shown to be 400 times more sensitive than the presumptive chemical color test that is currently the method employed for detection of small amounts of sulfur.     

外温变化下小鼠肝细胞18s rRNA降解与死亡时间关系研究

目的探讨在外界环境温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间的关系。方法小鼠断颈处死后置于10℃、15℃、20℃、25℃、和30℃温度下保存;从死后6h至72h,每6h分别提取肝细胞组织中总RNA。利用实时荧光定量PCR检测18s rRNA循环阈值(Ct值)的变化。应用插值函数进行分析拟合,建立死亡时间推断方程。结果各温度组Ct值随死亡时间延长均呈上升趋势,对所得数据进行插值拟合,得到一定温度变化区间内(10℃~30℃),Ct值变化与PMI关系的三元五次曲面方程:f(x,y)=-426.9+30.82x+44.48y-1.297x~2-1.837xy-1.388y~2+0.034 38x~3+0.038 17x~2y+0.038 67xy~2+0.028 77y3-0.000 612 9x~4-3.897e~(-7)x~3y-0.001 223x~2y~2+0.000256 6xy3-0.000 537 4y~4+3.606e~(-6)x~5-2.846e~(-6)x~4y+1.009e~(-5)x~3y~2-3.439e~(-6)x~2y3-2.556e~(-7)xy~4+2.664e~(-6)y~5(r2=0.999 4)。结论在外界温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间关系符合三元五次方程分布,利用插值函数拟合的方法可在外界环境温度变化条件下进行死亡时间推断。