HPLC测定豨莶片剂中奇壬醇的含量

目的:建立豨莶片剂中奇壬醇的含量测定方法.方法:采用HPLC,色谱条件为:Phenomenex C18柱,乙腈-0.05 mol/L KH2PO4(125∶75)为流动相,流速1.0 ml/min,检测波长215 nm.结果:奇壬醇在0.133～2.660 μg范围内呈良好的线性关系(r=0.999 9),平均回收率为99.4%,RSD=2.12%;测定3批豨莶片剂中奇壬醇的含量分别为109.46,105.91,107.41 μg/片.结论:HPLC简便、准确、可控,可作为豨莶片剂的定量检测方法.     

应用低离子强度溶液提高血痕MN血型测定的灵敏度

应用低离子强度溶液能提高凝集试验的灵敏度。本实验采用低离子强度溶液及蛋清薄膜固定解离法对保存1～6年的258份血痕进行MN血型盲测。结果总正确率94.57％。证明应用低离子强度溶液解离法的灵敏度明显优于盐水解离法。     

大鼠死后不同组织电导率与死亡时间关系的研究

目的测定不同死亡时间大鼠脑、肺、肝和骨骼肌电导率,研究不同组织器官EC与PMI的关系。方法 SD大鼠处死后,保存于25℃恒温条件下,于死后即刻(0d)、1d、2d、3d、4d、5d、6d和7d提取大鼠脑、肺、肝和骨骼肌,四种组织器官与去离子水按照一定比例制成浸渍液,测定各组织器官浸渍液EC值;分析其EC值与PMI的关系,建立与PMI关系的回归方程;比较大鼠死后四种组织器官EC变化规律,探讨不同组织器官腐败进程。结果死后1d内骨骼肌与脑组织EC无显著变化,2~7d快速增加;而肝、肺EC值在1d内已开始增加,且2~7d内均快速上涨。四种组织器官EC与PMI的关系用三次方程拟合较好,其中肝的相关系数最高,R~2=0.96,且四种组织器官的EC值在不同的PMI区段之间呈现出不同的增长规律。结论大鼠脑、肺、肝和骨骼肌EC与PMI相关性均较好,测定尸体组织器官EC有望成为法医实践中PMI推断的有效方法。     

Characterization and Differentiation of Geometric Isomers of 3‐methylfentanyl Analogs by Gas Chromatography/Mass Spectrometry,Liquid Chromatography/Mass Spectrometry,and Nuclear Magnetic Resonance Spectroscopy

The cis and trans isomers of 3‐methylfentanyl and its three analogs were chemically synthesized, and these compounds were characterized and differentiated by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), and nuclear magnetic resonance (NMR) spectroscopy. The cis and trans isomers of the 3‐methylfentanyl analogs were completely separated by GC/MS. Although the high temperature of the GC injection port caused thermal degradation of β‐hydroxy‐3‐methylfentanyl, the degradation was completely suppressed by trimethylsilyl derivatization. The isomers were also well separated by LC/MS on an octadecylsilyl column with 10 mM ammonium acetate and methanol as the mobile phase. The proton NMR signals were split when the hydrochloride salts of the 3‐methylfentanyl analogs were dissolved in deuterated chloroform because stereoisomers were formed by the coordination of the hydrochloride proton to the nitrogen of the piperidine ring of the 3‐methylfentanyl analogs.     

Photo‐ and Thermal‐Degradation Studies of Select Eccrine Fingerprint Constituents

Abstract: Photo‐ and thermal‐degradation studies on eccrine fingerprint components are presented herein. Dilute distinct solutions of urea, lactic acid, and seven amino acids were deposited on steel coupons and Teflon^® disks, exposed to artificial sunlight or heat, extracted, and analyzed. This aim of this study was to determine whether the investigated eccrine components, previously determined to be Raman active for a parallel study, experienced photo‐ or thermally induced degradation, and if so, to determine the rate and identify any detectable products. Neither the amino acids nor urea exhibited photo‐degradation; however, when heated for a period of three minutes, the onset of thermal‐degradation was initiated at 100°C for the amino acids and 100°C for urea. Lactic acid, the major polymerization initiator of superglue fuming, showed photochemical and thermal‐degradation. These results could be used for future development of new latent fingerprint visualization methods, especially when lactic acid is degraded.     

Citrate Content of Bone as a Measure of Postmortem Interval: An External Validation Study

The postmortem interval (PMI) of skeletal remains is a crucial piece of information that can help establish the time dimension in criminal cases. Unfortunately, the accurate and reliable determination of PMI from bone continues to evade forensic investigators despite concerted efforts over the past decades to develop suitable qualitative and quantitative methods. A relatively new PMI method based on the analysis of citrate content of bone was developed by Schwarcz et al. The main objective of our research was to determine whether this work could be externally validated. Thirty‐one bone samples were obtained from the Forensic Anthropology Center, University of Tennessee, Knoxville, and the Onondaga County Medical Examiner's Office. Results from analyzing samples with PMI greater than 2 years suggest that the hypothetical relationship between the citrate content of bone and PMI is much weaker than reported. It was also observed that the average absolute error between the PMI value estimated using the equation proposed by Schwarcz et al. and the actual (“true”) PMI of the sample was negative indicating an underestimation in PMI. These findings are identical to those reported by Kanz et al. Despite these results this method may still serve as a technique to sort ancient from more recent skeletal cases, after further, similar validation studies have been conducted.     

室外温度与室内恒温下EC随死后经历时间的变化

目的在室外环境和室内恒温条件下测定昼夜不同时间猪后腿肌肉电导率(electrical conductivity,EC)值,分析并比较两种环境条件下,EC值随死后经历时间(time since death, TSD)变化的规律。方法取5块即刻屠宰的猪后腿肌肉,均分为两份,随机分成两组,分别置于秋季室外环境和室内18℃恒温环境中。在死后10d内分别于早晚8时(每隔12h)取样,测定其浸渍液EC值。结果两种环境条件下,EC随TSD变化的趋势在整体上是一致的,二者相关性均较好(R2室外=0.971,P室外=0.004,R2室内=0.98,P室内=0.002)。室外环境温度下,肌肉的EC值在白天增长明显,夜间增长不明显,尤其环境温度低于13℃时,出现明显的平台现象,与室内恒温条件下肌肉EC值持续上升的变化趋势有显著的差异。结论无论室外环境温度还是室内恒温下,肌肉EC与TSD的相关性均较好,但在具体分析时,应考虑到夜间低温平台期造成的时间延搁。     

液相色谱一高分辨质谱联用技术在毒物筛选分析中的应用

毒物种类的广泛性、目标化合物的不确定性以及检材的多样性、特殊性,使得毒物筛选技术一直受到法医毒物分析工作者的重视.液相色谱-高分辨质谱联用技术凭借液相色谱强大的分离功能及高分辨质谱超高的质量分辨率和精确分子质量测定功能,结合一级、二级谱库匹配以及同位素离子丰度比,在化合物的筛选定性方面表现出强大的优势.本文综述了液相色...     

液相色谱-串联质谱法筛查鉴定203种毒品

目的建立203种毒品的液相色谱-串联质谱筛查鉴定方法。方法选用Accucore TM Phenyl/Hexyl苯基己基柱(100 mm×2.1 mm,2.6μm)为色谱柱,柱温50℃,以甲醇乙腈混合溶剂(体积比1:1,含0.1%甲酸和2 mmol/L甲酸铵)、水(含0.1%甲酸和2 mmol/L甲酸铵)作为流动相进行梯度洗脱,流速0.4 mL/min。质谱采用电喷雾正离子模式(ESI+)进行离子化,使用多反应监测(MRM)模式采集数据,总分析时间14 min。结果该方法实现了203种毒品的筛查鉴定分析,各目标物的方法检出限均为10 ng/mL。结论建立的筛查鉴定方法具有快速、准确、灵敏等优点,能够满足禁毒工作的日常需要。     

HPLC测定爽咽茶中绿原酸的含量

目的：建立爽咽茶中绿原酸含量的测定方法。方法：采用HPLC测定炎咽茶中绿原酸的含量，采用C18柱，乙腈-4．0g／L磷酸(10：90)为流动相，检测波长为327nm。结果：平均加样回收率为97．75％，RSD为1．40％。结论：本法操作简便、易行，具有实用性。