毛发中毒品分析

毛发分析在法庭毒品分析领域有其独特的优势,很多国家的法化学实验室,毛发分析已成为毒品检测的常规操作,并已得到了法庭的承认、采纳。本文对毒品进入毛发的机制、毛发的现场勘查、毛发中毒品分析程序、毛发中毒品分析结果的评判进行了综述。简单地介绍了毛发在现场勘查中采取、包装、送检的基本方法和技术人员在操作过程中的注意事项,以及针对毛发检验中的特殊技术处理;另外,介绍了毛发中毒品分析的特点,通过分析毛发毒品的药理机制,总结出了一些高效、便利、快速的毒品分析方法,并对各种方法进行了介绍,得出了毛发中毒品分析结果的一些特点。     

人毛发中吗啡类毒品的色谱检测方法文献分析

吗啡类毒品是我国滥用人数较多,也是危害性较大的毒品品种。与传统的人体体液检材(血液、尿液、唾液等)相比,毛发检材以其易获得性、易保存、易重复取样、长时间的检测窗口等优势逐渐应用于司法鉴定、毒驾检测、临床毒物分析等领域。本文整理归纳了近十年来(2007年~2017年)发表的测定人毛发中吗啡类毒品滥用物质相关文献,并从毛发样品的前处理方法、毛发样品的色谱检测方法、受试者毛发样本检测、毛发检测结果与毒品滥用关系判断等方面进行综述分析,为相关领域研究提供参考。     

运输毒品罪死刑裁量的影响因素研究——基于2018-2020年全国运输毒品罪死刑裁判文书的分析

在司法实践中,查获毒品种类、查获毒品数量、坦白、认罪认罚、再犯、运输方式、运输起点、案发地点等因素对毒品运输行为人是否被判处死刑具有影响能力;查获毒品种类、查获毒品数量、主体身份、毒品流通、国际贩毒、运输方式、运输次数等因素对毒品运输行为人的死刑执行方式具有影响能力。但是,查获毒品种类的因素影响能力被毒品折算过程稀释而只能间接体现,毒品因素的影响结构在事实上仍然是单一化的。另外,人身危险性因素的实际影响能力与理论预想之间存在差距,社会危害性因素对"死刑圈"和"死缓圈"入圈影响程度的倾向性也存在偏差。为优化运输毒品罪的死刑裁量,应从三方面进行。一是使查获毒品纯度具有影响能力,建构复合型毒品基础性情节考量模式;二是增加"利用公共交通工具随行运输毒品"为从重处罚情节,夯实多元化法定因素影响能力结构;三是提前进行逻辑层次设定,区分同一性裁量因素对两次入圈的影响程度。     

毒品代谢动力学在毒驾法庭判定标准中的应用和展望

毒驾成为影响我国交通安全的重要因素,而毒驾的法庭评定标准尚未建立,特别是毒品代谢物浓度对驾驶行为的影响尚不明确。随着法庭科学的发展,许多研究者对代谢动力学进行了研究,并取得了一定的成果。本文综述毒品代谢动力学研究及其在法庭科学中的应用状况,概要介绍毒品代谢动力学的研究现状、研究方法及研究成果,并提出结合驾驶行为能力和心理测验,开展临床的毒品代谢动力学、吸毒人员"代谢指纹图谱"及其与驾驶行为能力关系的研究,完善毒驾检测技术标准,构建合理阈值,进一步提出毒驾的法庭判定标准。     

萃取方式对海洛因滥用者毛发中代谢物分析的影响

目的比较液相萃取和固相萃取对毛发中海洛因毒品代谢物分析的影响。方法对海洛因吸食者毛发和空白添加标准品毛发经甲醇超声后的提取液分别进行液相萃取、固相萃取,然后进行衍生化和GC/MS-SIM检测。结果利用固相萃取法对添加6-单乙酰吗啡的毛发进行萃取和测试,6-单乙酰吗啡的回收率为32.0%,相对标准偏差(RSD)为2.4%;而液相萃取回收率为52.6%,相对标准偏差(RSD)为4.6%。结论固相萃取较之液液萃取,有更好的重复性,更少的杂质干扰和有机溶剂消耗等优势,但甲醇超声液需要挥干后才能进行固相萃取,而且6-单乙酰吗啡的水解率高。     

萃取方式对海洛因滥用者毛发中代谢物分析的影晌

目的比较液相萃取和同相萃取对毛发中海洛因毒品代谢物分析的影响。方法对海洛因吸食者毛发和空白添加标准品毛发经甲醇超声后的提取液分别进行液相萃取、同相萃取,然后进行衍生化和GC／MS—SIM检测。结果利用同相萃取法对添加6-单乙酰吗啡的毛发进行萃取和测试,6-单乙酰吗啡的回收率为32．O％,相对标准偏差（RSD）为2．4％;而液相萃取回收率为52．6％,相对标准偏差（RSD）为4．6％。结论固相萃取较之液液萃取,有更好的重复性,更少的杂质干扰和有机溶剂消耗等优势,但甲醇超声液需要挥干后才能进行同相萃取,而且6-单乙酰吗啡的水解率高。     

广东地区打击外国人涉毒犯罪中的难点问题研究

当前，国际上毒品供给能力持续增强，国内毒品需求不断上升，广东地区因其特殊的地理位置、国际化程度高、物流业发达等因素成为我国与国际贩毒集团斗争的桥头堡。影响广东地区外国人实施毒品犯罪的因素复杂，既有国际因素也有地方因素，既受我国外交政策影响也受外国人管理制度影响，同时也受办案程序、办案队伍素质、经费保障等多项因素干扰。探讨在打击外国人涉毒犯罪中存在的问题有利于找准原因，提出解决方法。     

安徽省毒品犯罪问题研究

安徽省已从开始私种罂粟发展为外流贩毒与消费并存的省份,毒品犯罪问题是影响安徽省社会治安的一大因素,本文在调研的基础上,从三个方面对安徽省毒品犯罪问题进行了研究:一是介绍了安徽省毒品犯罪的概况和规律特点,并预测了以后的毒品犯罪发展趋势;二是科学分析了安徽省毒品犯罪日趋严峻的主客观原因;三是有针对性地提出了安徽省毒品犯罪的对策。     

涉毒案件毒品定量鉴定是量刑的重要节点

涉毒案件中毒品的数量和含量是决定犯罪行为社会危害性大小的一个十分重要的因素,也是司法机关对犯罪分子课以刑罚的重要依据。毒品数量和含量认定的正确与否,关系到犯罪嫌疑人的犯罪的主观故意与案件量刑。当前,司法机关在办理的许多毒品犯罪（特别是可能判处15年以上刑罚）案件缺乏毒品定量鉴定结论,影响案件审理。笔者从法律和公平公正等方面探讨毒品含量分析的重要性。     

毒品犯罪中代购毒品行为的司法认定

代购毒品与居间介绍买卖毒品的区别主要在于行为人主观上是否具有帮助他人贩卖毒品的故意.可结合以下因素界定:一是行为人与吸毒人是否有亲密关系,仅为亲友代购少量毒品,一般不认定为居间介绍毒品;二是根据行为人是积极为吸毒人寻找购毒渠道或已知购毒渠道而为吸毒人购毒而奔走,还是无明显偏向性、仅据所知毒源偶然促成交易进行判断;三是结合用于代购毒品的资金流向界定,先予垫付毒资,交易后向吸毒人索要的行为更符合居间介绍买卖毒品特征.     

Evidence for bias in hair testing and procedures to correct bias

A number of in vitro experiments show that different hair samples incorporate differing amounts of drugs under identical conditions. Incorporation of cocaine and morphine tends to be correlated with race, in that the hair of African American females incorporates higher concentrations of cocaine than does the hair of Caucasian males or females. Extrapolation of these data into populations has been fraught with difficulties because the dosages of drugs and their use patterns are unknown. Cosmetic treatments and hygiene alter drug binding, which must be considered in comparing populations because cosmetic treatments are often group dependent. Four reasons are proposed that account for the uptake and retention of drugs by hair and that may differ among groups: (1) permeability and other characteristics of the hair due to genetic influences, (2) cosmetic hair treatments and hair care habits (which may be culturally influenced), (3) drug removal during personal hygiene, and (4) manner and route of drug administration which can affect passive exposure to residual drugs in the environment. The data supporting bias in hair testing are reviewed and methods are proposed that use either the uptake of dyes or the incorporation of drug homologs to reduce bias.     

Hair analysis by immunological methods from the beginning to 2000

Immunoassays for hair testing must satisfy three requirements: (1) They must have cross-reactivity with parent drug and lipophilic metabolites actually found in hair (2) they must not experience interference from the dissolved hair matrix and (3) they must be titered for cutoffs appropriate to the drug concentrations found in hair. Because the analytes found in hair after drug use are generally the parent drug or its lipophilic metabolites, immunoassays developed and intended for urine testing are not suitable for hair. Immunoassays whose antibodies are bound to a solid support, such as coated-tube radioimmunoassay or coated-plate ELISA tests, experience less matrix interference than those which use other means of separation of bound and free fractions. Homogenous assays are not suitable for hair testing because the hair matrix frequently interferes in the detection of the signal. Historically radioimmunoassays for drugs of abuse were first used for detecting drugs in hair. Currently ELISAs and coated-plate 96 well microplate EIAs are employed for screening hair digests or extracts for drugs. The optimum cutoffs for immunoassays for drugs in hair should be chosen based on the analyte concentration which produces the fewest false positive or false negative results when applied to tests of hair from known users and non-users of drugs. A hair immunoassay test at these cutoffs should have a sensitivity and specificity of better than 90%. The predictive value of the test will depend on the prevalence of drug use in the tested population. Cutoffs or decision thresholds for immunoassays used for screening for drugs should not be at the limit of detection of the assay because that produces a very large incidence of false positives. Because immunoassays are ligand-binding assays, they have a short range of linearity with low precision at both ends of the range. In the future, immunoassays will continue to be used for screening hair and other matrices for drugs of abuse because they provide rapid, inexpensive automated procedures for separating negative specimens from those which are suspected of containing drugs. For forensic purposes, all positive results must be confirmed by an independent analysis using a procedure based on a different property of the analyte. An immunoassay test should not be confirmed by a second immunoassay test but by a chromatographic test performed on a different dissolved or extracted aliquot of the original specimen.     

Comparative investigations on the uptake of basic substances into the human keratinocyte cell line HaCaT--a model for the uptake of xenobiotics into the keratinocytes of the hair follicle

The human cell line HaCaT was used to study drug uptake by keratinocytes as an in-vitro model to elucidate drug incorporation into anagen hair follicle. The basic drugs under investigation were taken up very rapidly resulting in a concentration plateau in the keratinocytes which was dependent on the drug concentration in the cell culture medium. The results obtained for HaCaT clearly demonstrated the existence of a partition-equilibrium between the extracellular and intracellular drug concentrations. Only small amounts of the offered drugs were taken up and remarkable differences were observed showing a decreasing uptake for imipramine > haloperidol > cocaine/benzoylecgonine. Total protein content in the culture medium was 3.5 +/- 0.3 mg/mL and the protein binding of the drugs to the foetal serum proteins was found to be negligible in the experiments. Overall, the in vitro findings were consistent with previous observations for in vivo drug incorporation into hair. In particular, an explanation was found for the correlation between the AUC-value and hair concentration observed in animal studies as well as for the generally low drug concentrations in non-pigmented hair.     

Effect of murine retroviral infection on hair and serum levels of cocaine and morphine.

LP-BM5 retrovirally infected female C57BL/6J mice were administered cocaine, morphine or both by daily intraperitoneal injection for 9 weeks. Drug concentrations were measured by radioimmunoassay in serum and in hair extracts. Hair samples obtained from all drug-treated mice were positive for the drug injected, while none of the saline-treated mice had detectable drug levels in hair or serum. The average morphine concentration obtained from non-infected mice was 11 ng/mg hair whereas the amount found in the LP-BM5-infected mice was significantly higher (20 ng/mg hair). Mice injected with both morphine and cocaine were given 50% of the regular dose of each drug and drug levels in the hair of these animals were approximately half that of mice injected with the full dose of the single drug. Non-infected mice treated with both drugs had a mean value of 7 ng morphine/mg hair and 374 ng cocaine/mg hair while retrovirus-infected mice had significantly higher concentrations, 10 ng morphine/mg hair and 1160 ng cocaine/mg hair (P less than 0.001). Serum concentrations of cocaine and morphine were significantly higher (P less than 0.01) in the retrovirus-infected animals from 40 min to 1.5 h. The increased concentrations of cocaine and morphine in serum during retrovirus infection are accompanied by a significant increase in the amount of drug incorporated into the hair matrix. This change indicates that retroviral infection may influence the disposition of these drugs in the systemic circulation.     

Value of the concept of minimal detectable dosage in human hair

The influence on drug incorporation of melanin affinity, lipophilicity, and membrane permeability is of paramount importance. Despite their high lipophilicity, some drugs have quite low incorporation rate into hair, suggesting that the higher incorporation rates of basic drugs (cocaine, amphetamines.) than neutral (steroids, benzodiazepines, cannabinoids…) or acidic ones are strongly related to the penetrating ability of the drug to break through the membrane based on the pH gradient between blood and the acidic hair matrix. When using hair analysis as a matrix during investigative analysis, e.g. workplace drug testing, doping, driving under the influence, drug-facilitated crime, the question of importance is to know whether the analytical procedure was sensitive enough to identify traces of drugs; this is particularly important when the urine sample(s) of the subject was positive and the hair sample(s) was negative. It has been accepted in the forensic community that a negative hair result cannot exclude the administration of a particular drug, or one of its precursors and the negative findings should not overrule a positive urine result. Nevertheless, the negative hair findings can, on occasion, cast doubt on the positive urine analysis, resulting in substantial legal debate and various consequences for the subject. The concept of minimal detectable dosage in hair is of interest to document the negative findings, but limited data is currently available in the scientific literature. Such data includes cocaine, codeine, ketamine, some benzodiazepines and some unusual compounds. Until laboratories will have sensitive enough methodologies to detect a single use of drug, care should be taken to compare urine and hair findings.     

Detection of antidepressant and antipsychotic drugs in human hair

The presence of therapeutic drugs and their metabolites in the hair of psychiatric patients was investigated using gas chromatography (GC)-mass spectroscopy (MS)-electron ionization (EI) and GC-MS-chemical ionization (CI). In hair samples tested from 35 subjects, carbamazepine, amitriptyline, doxepin, trihexyphenidyl, chlorpromazine, chlorprothixene, trifluoperazine, clozapine and haloperidol were detected, with maximal concentrations of 22.5, 57.7, 183.3, 15.6, 68.2, 30.0, 36.8, 59.2 and 20.1 ng/mg of hair sample, respectively. Chlorpromazine and clozapine concentrations in the hair were found to be dependent on the dosage used and their correlation coefficients were 0.8047 (P<0.001, n=16) and 0.7097 (P<0.001, n=16), respectively. Segmental analysis demonstrated that there was a correlation between the history of subject's drug exposure and the distribution of drug along the hair shaft. Our results also show that drug analysis in hair may provide useful information about drug treatment and the history of usage, and that drugs can be detected in normally kept hair for at least 16 months after intake.     

Differentiation between drug use and environmental contamination when testing for drugs in hair

The differentiation between systemic exposure and external contamination for certain drug groups has been frequently referred to as one of the limitations of in drug testing in hair. When hair samples are used, three steps are usually employed in order to minimise the possibility of external contamination causing a misinterpretation. The first consists of decontaminating hair samples by washing the hair before analysis, the second is the detection of the relevant metabolites in the hair samples and the third is the use of cut-off levels. Difficulty in the interpretation arises when metabolites are not detected either due to external contamination of the hair or low doses of the drugs used. A wash protocol needs to be practical and ideally remove any drug deposited on the external portion of the hair.     

Potential problems with the interpretation of hair analysis results

Due to differences in hair growth rate depending on anatomical region, age, gender, ethnicity and interindividual variability, interpretation of parent drug or/and metabolite concentrations in hair is not easy. Furthermore, as drug incorporation mechanisms into hair matrix is not yet fully understood, it is rather difficult to extrapolate details on time and dose from hair segment analysis. If incorporation sources other than from bloodstream (skin secretions and/or external/environmental contamination) are considered, interpretation becomes even more complicated. For evaluating possible passive contamination, it is essential to consider specific identification of metabolites, use of metabolite-to-parent drug ratios, assays of decontamination washes and analysis of specimens collected from other body parts. Cosmetic hair treatment, natural and artificial hair colour, differences in hair structure and specificity of analytical methodology may represent other bias sources affecting concentrations of drugs in hair. A suitable cut-off level related to the LOD will allow correct identification of drugs or metabolites in hair. Regarding the performance of different hair testing laboratories, little information is available at this time to what extent test results are comparable and their interpretation is consistent. Frequency of drug consumption and time intervals between multiple consumption or lag time between consumption and appearance in the hair has not been fully investigated and needs further research.     

Opiate levels in hair

By means of radioimmunoassay-technique, hair samples of users, drug related fatalities, carcinoma patients receiving morphine and of experimental guinea pigs receiving codeine were investigated for opiates. The RIA-investigations require a minimum of material; our routine procedures need only 50 mg of hair. No correlation existed between administered doses of opiates and their concentrations in hair of both human and experimental animals. By sectioning the hair, the approximate period of drug use in man could be detected. However, these findings could not be confirmed by the animal experiments. The growth rate of the hair, diffusion and adhesion processes may influence the transport of drugs along the hair. External contaminations and washing procedures were shown to increase or diminish the drug concentration of the samples.