液液萃取-超高效液相色谱-串联质谱法测定常见食用植物油中5种鸦片生物碱

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。     

接触DNA在法医实践中的应用研究进展

人体在接触物体后,会在其表面留下少量接触DNA。对接触DNA的检验是目前法医DNA检验技术的热点和难点。接触DNA的检验成功率差异较大,受各环节多重因素影响。影响接触DNA检验成功率的主要因素有接触DNA检材的准确发现、接触DNA的提取与纯化以及扩增策略的选择和结果分析等。本文详述了接触DNA检验过程的进展及研究展望。     

Alternative direct-to-amplification cell lysis techniques for forensically relevant non-sperm cells

While efforts have been made to reduce the pervasive backlog of sexual assault evidence collection kits, the actual laboratory process remains very time-consuming due to the requirement of a differential lysis step before DNA purification, as well as intricate mixture analysis towards the end of the DNA workflow. Recently, an alternative, direct-to-amplification sperm lysis method (using 1 M NaOH) was identified. However, a direct cell lysis method for non-sperm cells has not been identified yet. Thus, the primary objective of this work was to find an alternative method that is quick, inexpensive, and does not require multiple purification steps for the lysis of non-sperm cells in sexual assault samples. In this study, vaginal swab samples were lysed with the control method, prepGEM™, as well as six alternative reagents: alkaline buffer with 25–200 mM NaOH, high-salt stain extraction buffer, modified radioimmunoprecipitation assay (RIPA) buffer, mammalian protein extraction reagent (M-PER™), digitonin buffer, and urea/thiourea buffer. Quantification using Quantifiler® Trio of vaginal and semen lysates revealed that the alkaline (25 mM NaOH) and M-PER™ methods were efficient for the lysis of vaginal epithelial cells without substantial sperm cell lysis. Following quantification, analysis of STR profiles from vaginal lysates revealed that the M-PER™ method showed promising results across all metrics examined, including the percentage of detected STR alleles, mean peak heights, peak height ratio, and interlocus balance. Thus, this method was recommended as an alternative to the traditional differential lysis method for non-sperm cells given its ability to produce amplification-ready lysates without any DNA purification step.     

固相萃取-气相色谱-质谱法检验人血浆中的右美托咪定

目的采用固相萃取结合气相色谱-质谱法(SPE-GC/MS)检验人血浆中盐酸右美托咪定。方法采用SPE提取血浆,用GC-MS/MS方法测定。结果盐酸右美托咪定在0.2μg/m L~5.0μg/m L范围内与峰面积呈现良好的线性关系(r2=0.999 1),检出限为20.0ng/m L,回收率为86.1%~91.5%,日内日间精密度均小于7.86%。结论本方法操作简单,结果准确,可以作为测定人血浆中右美托咪定的方法。     

尿液中DNA的提取与检验

尿液中DNA的STR分型检验有一定的应用价值:国外文献报道过应用于运动员兴奋剂控制^[1]中可疑尿检样品的个体识别,国内则偶有案发现场提取到尿液、尿冰、尿斑并成功进行个体识别的案例报道。与血液、精斑、唾液等检材相比,尿液STR分型的检出率较低,主要是与尿液中的成份有关。本文重点分析人类尿液成分,分类总结目前可用于提取尿液中DNA的多种方法,分析可能影响尿液STR分型检验结果的因素。     

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler? BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.     

Developmental Validation of the PrepFiler™ Forensic DNA Extraction Kit for Extraction of Genomic DNA from Biological Samples*

Abstract: The PrepFiler? Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples. The kit facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials: 0.1 and 40 μL of human blood (donor 2) provided 14 and 2883 ng of DNA, respectively. Following the revised SWGDAM guidelines, performance of the developed method was investigated using different sample types including saliva on swabs, semen stains on cotton fabric, samples exposed to environment, samples with polymerase chain reaction (PCR) inhibitors, blood stains (on denim, cotton cloth, and FTA^® paper), and touch evidence‐type samples. DNA yields for all samples tested were equal or better than those obtained by both phenol–chloroform extraction and commercial kits tested. DNA obtained from these samples was free of detectable PCR inhibitors. Short tandem repeat profiles were complete, conclusive, and devoid of PCR artifacts.     

The Stability of Collected Human Scent Under Various Environmental Conditions*,†

Abstract: Human scent evidence collected from objects at a crime scene is used for scent discrimination with specially trained canines. Storage of the scent evidence is usually required yet no optimized storage protocol has been determined. Storage containers including glass, polyethylene, and aluminized pouches were evaluated to determine the optimal medium for storing human scent evidence of which glass was determined to be the optimal storage matrix. Hand odor samples were collected on three different sorbent materials, sealed in glass vials and subjected to different storage environments including room temperature, ?80°C conditions, dark storage, and UVA/UVB light exposure over a 7‐week period. Volatile organic compounds (VOCs) in the headspace of the samples were extracted and identified using solid‐phase micro‐extraction–gas chromatography/mass spectrometry (SPME–GC/MS). Three‐dimensional covariance mapping showed that glass containers subjected to minimal UVA/UVB light exposure provide the most stable environment for stored human scent samples.     

静松灵的检验

本实验建立了用固相萃取(SPE)、薄层色谱和气—质联用法(GC-MS)分析血、尿、肝中静松灵的方法,在1g尿、血、肝中添加0.01mg药物、回收率分别为96.1%、90%、67%.该方法简单快速准确,经动物实验及案件鉴定验证,效果较好.     

埋葬4年的开棺腐败尸体中安定、氯丙嗪等6种安眠药物的检验

本文介绍用SPE提取、GC/MS检验埋葬4年的开棺腐败检材中安定、氯丙嗪等6种安眠药物的新方法.哦