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。     

New Challenges for Law Enforcement

Against a background of high crime across Europe, this paper argues that there is scope for improving police performance in detection. It also suggests that a more balanced approach to crime control is needed, with a shift in policy emphasis toward prevention. Both improved police performance in detection and the approach advocated for increased preventive effort are rooted in science. The specific role of science and technology in the context of crime control is considered and its implications for public policy and police training are briefly discussed. It is suggested that the problem-oriented approach to crime prevention, as increasingly practiced by the UK police and those in other jurisdictions, could be described as approaching scientific method, and perhaps be promoted as such.     

HPLC-MS法测定鲜鱼中河豚毒素

目的建立用液相色谱-质谱（HPLC-MS）法测定鲜鱼中河豚毒素含量的方法。方法样品经粉碎、酸性水溶液提取、蛋白酶解、石油醚脱脂、有机溶剂甲醇沉淀、固相萃取柱净化后,以液相色谱-质谱法测定,外标法定量。结果鱼肉和鱼肝中河豚毒素在0.10～10 mg/kg范围内呈良好线性关系,相关系数分别为0.9998和0.9991,平均回收率为94.6%~102%,相对标准偏差RSD小于6.6%,方法的最低检出限为0.03 mg/kg。结论该方法操作简便、快速,为饮用水及水产品中河豚毒素的检测、相关的司法鉴定等提供了准确有效的科学依据。     

肝中杀鼠酮硅藻土提取高效液相色谱检测法研究

目的建立肝中杀鼠酮的硅藻土提取方法和高效液相色谱检测法。方法取0．5g肝匀浆，加69／5HC10。沉淀蛋白，准确取1／2上清液倒入装有3．1g硅藻土的层析柱中，用10mL二氯甲烷或乙醚洗脱，洗脱液中加入安定作为内标，水浴浓缩，用0．2mL甲醇定容，供高效液相色谱分析。结果提取率分别为98．1％和99．9％，检出限分别为14ng／mL和13ng／mL。结论该方法简便、快速、提取率高，可作为法医毒物常规检测手段。     

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.     

苯并二氮类药物及其主要代谢物的薄层色谱分析

目的建立饮料、血、尿中 11种常见苯并二氮类药物及尿中 7种主要代谢物的薄层色谱分析法(HPTLC)。方法分析物采用GDX10 1树脂进行固相萃取 ,乙醚作为洗脱溶剂。苯 :丙酮 (10∶6)等作为展开体系 ,改良碘化铋钾显色。结果所建方法绝对灵敏度 0 3～ 0 6μg,尿检出限 0 4～ 1 0 μg/ml、血检出限 0 6～ 1 0 μg/ml、饮料检出限 0 4～ 0 8μg/ml。结论HPTLC法简便、快速 ,适合作为常规毒物分析方法     

同时鉴定9种肉源种属的复合检测体系的建立及其应用

目的建立一种可以同时鉴定猪、牛、羊、鸡、鸭、猫、狗、鼠和鲤鱼的多重PCR检测方法,并测试其技术性能指标,评估其在法医学或食品安全事件中的应用价值。方法根据上述9种动物的线粒体细胞色素b基因,利用其片段中种间特异性强的序列设计引物,采用毛细管电泳检测平台对各种属PCR扩增产物进行检测,依据扩增片段长度的差异与标记的荧光对初始模板的肉源种属进行鉴别;并通过扩增特异性、实际样本测试、混合样本检测灵敏度等指标评价该方法在实际法医学或食品安全案件中的应用价值。结果经过验证,建立的同时鉴定9种肉源种属的复合检测体系对其中任意一个种属的检测特异性均较高,且灵敏度较强,能够满足绝大多数法医学或食品安全案件中的检测要求。结论本研究建立的肉源种属复合检测体系可以在法医学未知种属样本的鉴定及食品安全肉类掺假等案件中提供帮助。     

Validation of powder X-ray diffraction following EN ISO/IEC 17025

Powder X-ray diffraction (PXRD) is used widely in forensic science laboratories with the main focus of qualitative phase identification. Little is found in literature referring to the topic of validation of PXRD in the field of forensic sciences. According to EN ISO/IEC 17025, the method has to be tested for several parameters. Trueness, specificity, and selectivity of PXRD were tested using certified reference materials or a combination thereof. All three tested parameters showed the secure performance of the method. Sample preparation errors were simulated to evaluate the robustness of the method. These errors were either easily detected by the operator or nonsignificant for phase identification. In case of the detection limit, a statistical evaluation of the signal-to-noise ratio showed that a peak criterion of three sigma is inadequate and recommendations for a more realistic peak criterion are given. Finally, the results of an international proficiency test showed the secure performance of PXRD.     

Qualitative and quantitative analysis of cephradine in biological materials by high performance liquid chromatography

A reversed phase high performance liquid chromatographic method was developed for the determination of cephradine, one of the commonly used antibiotics, in biological materials. Mimic samples for stomach contents, miso soup, were applied to high performance liquid chromatography (HPLC) after centrifugation and purification by Sep-Pak C18 cartridge treatment. Serum samples deproteinized or urine samples diluted were directly injected into the HPLC. The recoveries of cephradine from these materials were 95-97% and the detection limit was 0.01 microgram/injection. This method was applied to the analysis of cephradine in stomach contents obtained by autopsy. After purification by the cartridge treatment, cephradine in the sample was identified and determined by HPLC and further confirmed by thin-layer chromatography (TLC) and mass spectrometry (MS).     

全血中西地那非的HPLC分析

目的建立血中西地那非的HPLC-DAD检测方法。方法用硅胶小柱分离提取血中的西地那非,HPLC-DAD分析。分析柱：Nova-pak C18（150×3.9mm）,5.0μm;保护柱：Phenom enex C18（ODS,4.0×3.0mm,Octade-cyl）;流动相A：0.06%三氟乙酸＋0.06%三乙胺＋0.25%乙腈,B：乙腈,梯度程序分离;DAD：230nm。结果血中西地那非线性检测范围为1.5-80.0μg/mL,最小检出限量为5ng,平均回收率：82.45%。结论本检验方法简单、准确、快速,适合于临床检测及刑事案件的快速分析。     

High performance liquid chromatographic determination of alcohols with reference to body distribution of methanol.

A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80-90%. The reproducibility of the results was always greater than 90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.     

A study on JPEG steganalytic features: Co-occurrence matrix vs. Markov transition probability matrix

Statistical feature selection is a key issue affecting the performance of steganalytic methods. In this paper, a performance comparison method for different types of image steganalytic features was proposed firstly based on the changing rates. Then, for two types of typical steganalytic features – co-occurrence matrix and Markov transition probability matrix, the performances of them were discussed and theoretically compared for detecting two types of well-known JPEG steganography that preserve DCT coefficients histogram and lead the histogram to shrink respectively. At last, a conclusion on the sensitivity comparison between components of these two types of features was derived: for the steganography that preserve the histogram, their sensitivities are comparable to each other; whereas for the other one (such as the steganography that subtract 1 from absolute value of the coefficient), different feature components have different sensitivities, on the basis of that, a new steganalytic feature could be obtained by fusing better components. Experimental results based on detection of three typical JPEG steganography (F5, Outguess and MB1) verified the theoretical comparison results, and showed that the detection accuracy of the fused new feature outperforms that of existing typical features.     

High performance liquid chromatographic determination of alcohols with reference to body distribution of methanol

A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80–90%. The reproducibility of the results was always >90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.     

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40 degrees C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116 +/- 0.012, 1.082 +/- 0.070 and 8.984 +/- 0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d = 1.000 was 1.040 +/- 0.040 in MAMP and 0.980 +/- 0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.     

高效液相色谱法测定生物体液中百草枯

目的建立HPLC检测生物体液中百草枯方法。方法弱阳离子交换固相萃取小柱提取,水溶性正相液相色谱分析,结合保留时间和紫外光谱对样品中百草枯进行定性。结果经该方法测得百草枯的最小检出限为10ng/m l血(S/N≥3),线性范围为0.1~10μg/ml。结论该方法快速、灵敏、准确,能有效祛除复杂生物基质中杂质干扰,使待测组分获得满意的峰形,适用于生物检材中百草枯的分析。     

高效液相色谱法快速分离测定血浆中的乌头碱

目的建立血液中乌头碱的高效液相色谱快速分析方法。方法以空白人血浆添加乌头碱标准品对血液样品的前处理方法、仪器测试条件、线性范围、精密度、回收率进行全面考查,建立乌头碱定量分析方法。对血液中所含乌头碱的浓度进行测定。结果该方法在血液中的线性范围是0.1~5.0μg/m l;最低检测浓度为0.1μg/m l;日内、日间精密度分别小于3.7%和4.5%;回收率在(97.0±4.1)%以上。结论所建方法实用、便捷,可对血液中乌头碱的含量进行快速测定。     

二维气相色谱检测爆炸残留物中TNT

目的建立二维气相色谱结合ECD检测爆炸残留物中TNT的方法。方法利用Dean-Switch系统进行二维无死体积切换，通过切换时间的准确选择，使粉尘样品提取液无需净化进样，即可达到分离彻底、高灵敏度。结果在案件检测应用中，效果良好。     

The detection of isoniazide in the cadaveric blood and plasma by high performance liquid chromatography with a diode matrix detector

The authors describe the analytical procedure for the rapid detection of isoniazide in the cadaveric blood and plasma using high performance liquid chromatography with a diode matrix detector (HPLC-DAD). The method is designed for toxicological and forensic medical analyses. The preliminary preparation of the samples includes protein precipitation with trichloroacetic acid, formation of isoniazide derivatives with cinnamic aldehyde, and chromatographic analysis on an Eclipse XDB-C18 column with registration of absorption at a wavelength of 340 nm. The mobile phase is a mixture of methanol and 0.05 M ammonium acetate buffer (50:50 v/v), pH 3.8. The detection limit is 0.5 mcg/ml in plasma and 1 mcg/ml in blood hemolizate. The qualitative determination is possible in a concentration range from 2 to 200 mcg/ml. Mean square deviation does not exceed 12% in a concentration interval from 2 to 50 mcg/ml.     

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.     

Detecting Feigned Attention-Deficit/Hyperactivity Disorder (ADHD): Current Methods and Future Directions

Feigned attention-deficit/hyperactivity disorder (ADHD) in adults is a significant issue in clinical settings, particularly regarding academic accommodations and access to controlled substances by university students. This article discusses the definitions, base rates, external incentives, psychometric detection strategies, and ethical implications of feigned ADHD. ADHD is characterized by a pattern of developmentally inappropriate inattentive, overactivity, and/or impulsivity, often persisting into adulthood. Estimates of the prevalence of non-credible ADHD in university settings range from 25 to 50%. Feigned ADHD may be detected with symptom and performance validity measures. The existing empirical research has failed to produce a clear psychometric solution to this important differential diagnosis. Identifying feigned ADHD is a difficult task, possibly because of the highly transparent, face-valid diagnostic criteria, and an atypical malingering strategy that evades established detection methods. Performance validity tests remain the best available method for identifying non-credible presentation during psychological evaluations of ADHD. Future practice recommendations should consider educational policy, diagnostic criteria, and psychometric research, including the development of self-report measures that reliably differentiate between genuine and feigned ADHD.