Routine forensic use of the mitochondrial 12S ribosomal RNA gene for species identification

Since July 2004, Mitotyping Technologies has been amplifying and sequencing a approximately 150 base pair fragment of mitochondrial DNA (mtDNA) that codes for 12S ribosomal RNA, to identify the species origin of nonhuman casework samples. The approximately 100 base pair sequence product is searched at http://www.ncbi.nlm.nih.gov/BLAST and the species match is reported. The use of this assay has halved the number of samples for which no mtDNA results are obtained and is especially useful on hairs and degraded samples. The availability of species determination may aid forensic investigators in opening or closing off lines of inquiry where a highly probative but challenging sample has been collected.     

Quantitative Analysis of Gamma‐Hydroxybutyrate at Endogenous Concentrations in Hair using Liquid Chromatography Tandem Mass Spectrometry

Abstract: A method capable of quantifying endogenous concentrations of gamma‐hydroxybutyrate (GHB) in human head hair was developed and validated using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). Hair was digested under alkaline conditions, and GHB was isolated using liquid–liquid extraction. LC/MS/MS was performed using atmospheric pressure chemical ionization in the negative mode, multiple reaction monitoring, and deuterated internal standard (GHB‐D₆). Linearity was observed between 0.1 and 100 ng/mg GHB (R² = 1.000). The limits of detection and quantitation in human hair were 0.2 and 0.4 ng/mg, respectively. Accuracy at 2 ng/mg and 10 ng/mg was determined to be 97% and 94%, and intra‐assay CVs at these concentrations were 5.2% and 7.4% (n = 4). Beta‐hydroxybutyrate (BHB), alpha‐hydroxybutyrate, gamma‐butyrolactone, and 1,4‐butanediol did not produce an interference, and there was negligible ion suppression or enhancement from the matrix.     

Segmental hair analysis for flunitrazepam and 7-aminoflunitrazepam in users: a comparison to existing literature

The availability of more quantitative data on flunitrazepam (FLU) and 7-aminoflunitrazepam (7AF) would aid in obtaining a better understanding of the interpretation of FLU concentrations in human hair. The purpose of this study was to provide concentrations of FLU and 7AF in hair segments of 22 FLU users. Quantitative data regarding hair concentrations of FLU and 7AF from various types of cases were also reviewed to give a comprehensive overview of the comparability of different studies. Three to six 1 cm segments of scalp hair from 22 FLU users were analyzed by a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. FLU and its metabolite were confirmed in the hair segments from all cases. Concentrations of FLU and 7AF in the segments ranged from 0.01–0.16 ng/mg (median of 0.03) and 0.01–0.34 ng/mg (median of 0.09), respectively. Most cases had FLU and 7AF distributions along the hair segments that were suggestive of repeated drug use. A summary of the published concentrations gives valuable data and can assist forensic investigators in their estimations of drug use history and patterns.

Key points

• A method using LC–MS/MS to quantify flunitrazepam and its metabolite was described.
• Segmental analysis of flunitrazepam and its metabolite in human hair was reported.
• A comprehensive overview of quantitative data was given.

     

Testing human hair for cannabis

To validate information on cannabis use, we investigated human hair and pubic hair for cannabinoids (THC and THC-COOH) by gas chromatography/mass spectrometry. Samples (100 mg approximately) were decontaminated with methylene chloride, then pulverized and dissolved in 1 ml 1 N NaOH for 10 min at 95 °C in the presence of 200 ng of deuterated standards. After cooling, samples were extracted by n-hexane/ethyl acetate after acidification with acetic acid. After derivatization of the dry extract by PFPA/PFP-OH, the drugs were separated on a 30-m capillary column and detected using selected-ion monitoring (m/z 377 and 459 for THC and THC-COOH, respectively). Forty-three hair samples were obtained from fatal heroin overdose cases. Among them, 35% tested positive for cannabinoids. Hair concentrations ranged from 0.26 to 2.17 ng/mg (mean, 0.74 ng/mg) and 0.07 to 0.33 ng/mg (mean, 0.16 ng/mg) of THC and THC-COOH, respectively. As is generally the case for other drugs detected in hair, metabolite concentration was always lower when compared to the parent drug concentration. In pubic hair, THC concentrations ranged from 0.34 to 3.91 ng/mg (mean, 1.35 ng/mg) and THC-COOH concentrations from 0.07 to 0.83 ng/mg (mean, 0.28 ng/mg). In most cases, the highest cannabinoid concentration was found in pubic hair, suggesting that this sample may be the more suitable for cannabis testing.     

GC/MS研究海洛因代谢物在吸毒者体内的分布

应用GC／MS－SIM测定了海洛因代谢物吗啡在两例海洛因延缓死亡者的体内分布,并分析了收集到的7例案子的毛发（头发、腋毛和阴毛）中6-单乙酰吗啡和吗啡含量。生物检材和毛发经酸水解、提取、醋酸酐或双（三甲基硅基）三氟乙酰胺（BSTFA）衍生化,然后进行GC／MS-SIM分析。结果表明尿、胆汁和肝脏是判定死者是否曾使用海洛因的最佳检材;毛发分析与生物检材相比有其独特的优点,可提供数月甚至数年的用药情况。为公安司法机关打击吸毒、惩治犯罪提供更可靠、有效的证据。     

Accumulation of explosives in hair--part II: factors affecting sorption

This study examines the sorption of eight explosives (2,4,6-trinitrotoluene [TNT]; pentaerythritol tetranitrate [PETN]; hexahydro-1,3,5-trinitro-s-triazine [RDX]; diacetone diperoxide [DADP]; triacetone triperoxide [TATP]; ethylene glycol [EGDN], nitroglycerin [NG]; and 2,4-dinitrotoluene [DNT]) to human hair. The study uses only cut hair, which is exposed to explosive vapor. The vapor transfer studies reported herein indicated that hair did not reach saturation even after 2.5 years of exposure to TNT. While previous studies showed black hair sorbed more explosive than blond or brown, this study reports that red hair sorption is similar to black, while grey hairs, exposed along with black hair from the same individual, sorbed significantly less explosive than the same individual's black hairs. In a study using only black hair, a slight racial bias was observed with sorption greater for Mongoloid hair as compared to Caucasian or Negroid. Only for Mongoloid hairs were enough samples studied to examine for a gender bias, but one was not observed. There was much variability in results in all categories (hair color, race, and gender) that trends were established only in general terms. Hair at different ages was tested for a few individuals. Detailed studies focused on the sorption of TATP and TNT as these appear to be sorbed most differently-TATP mainly on the hair surface and TNT both on the surface and in the cortex. The uptake of high vapor pressure explosives (e.g., TATP) and moderate vapor pressure explosives (e.g., TNT) by hair was rapid and could be detected within about 1 h of exposure. Both explosives were readily sorbed by pure melanin.     

Necrophagous Caterpillars Provide Human mtDNA Evidence*

Abstract: Decomposition of large mammalian carcasses is greatly accelerated through the action of insects. Specialized feeders capable of digesting keratin and collagen found in skin, hair, and tendons and ligaments are attracted to corpses in late stages of dry decomposition and include Tinea pellionella, the casemaking clothes moth, and Tineola bisselliella, the webbing clothes moth (Lepidoptera; Tineidae). Until now, details of the caterpillar behavior as necrophagous insects were vague. Here, we detail the behavior of each species and document the incorporation of human hair into the portable larval shelters constructed by the caterpillars of T. pellionella. Hair of the decedent used as building material for caterpillar shelters provided enough starting template to amplify and sequence the HVI and HVII sections of the control region (mtDNA) of the decedent.     

水溶性壳聚糖的制备及其在化妆品中的应用

用一氯乙酸对壳聚糖进行了化学改性,将酸溶性壳聚糖转变为水溶性羧甲基壳聚糖,并对其理化性质(如取代度、特性粘度、吸湿性和保湿性等)进行了测定。结果表明,羧甲基壳聚糖具有良好的水溶性,应用在啫喱水方面具有良好的吸湿性、保湿性以及定型、护发作用。     

氯胺酮滥用的毛发分析研究

目的建立毛发中氯胺酮及其代谢物的分析方法并探索氯胺酮进入毛发的机理。方法通过建立豚鼠连续给药(不同剂量)实验模型获取阳性头发和采集氯胺酮滥用者头发,经处理后用GC/MSscan和SIM法分析,以鉴别、确认毛发中氯胺酮及其代谢物。结果豚鼠毛发中氯胺酮的质量分数与给药剂量存在明显的正相关性。毛发中氯胺酮质量分数依白色、棕色、黑色毛发顺序随毛发中黑色素的质量分数增加而增加。豚鼠毛发中氯胺酮与代谢物NK质量分数之比为2.33～12.94,仅在高剂量组的豚鼠毛发中才检测到DHNK,其质量分数与NK接近。15名氯胺酮滥用者黑色头发中均检出原体和代谢物NK,但DHNK少见。豚鼠毛发中代谢物相对质量分数明显高于人。结论本实验结果很好地反映了药物进入毛发代谢过程与药物和黑色素亲和力以及药物的亲脂性密切相关这一规律,但人和动物在药物代谢及进入毛发的难易程度上存在差异。本方法可以用于法庭毒物分析领域头发中氯胺酮的检测。     

脱落毛发及毛干DNA的STR分型研究

目的探讨脱落毛发及毛干细胞核DNA提取、含量和STR分型问题。方法对脱落毛发或毛干进行DNA提取和定量,使用低扩增体系、增加循环次数和多次平行扩增等方法扩增DNA样本,采用叠加比较的方法分析STR分型。结果15cm脱落毛发样品DNA含量大于0．3ng的样品占52．8％,STR分型成功率为55．6％;15cm毛干样品DNA含量大于0．3ng的样品占30．6％,STR分型成功率为25％。结论采用增加循环次数、多次平行扩增等LCN—STR分型方法和Mini—STR试剂盒有助于脱落毛发及毛千的STR基因座分型获得。