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.     

Patterns in drug use in the United Kingdom as revealed through analysis of hair in a large population sample

This paper presents an overview of the most common sectioning patterns utilised in the analysis of hair for drug use; report on the major user groups (sectors) that currently make use of hair analysis in the United Kingdom (UK); present the results for the different drug groups analysed in samples of hair samples analysed at TrichoTech between 2001 and 2005.A total of 186,084 tests on 34,626 hair samples were performed for the commonly requested drug groups. There were 145,799 enzyme-linked Immunosorbent positive screening tests (ELISA), which were subsequently confirmed by gas chromatography equipped with mass spectrometry detection (GC–MS). The two major sectors were the Medico-Legal sector (65%) and Workplace (20%). Police (Forensics), Clinical Monitoring, Schools, Research and Insurance accounted together for the remaining 15% of the samples. Combinations of several sections patterns were requested covering periods from the most recent month up to 24 months. The most common sectioning pattern was one single section measuring 3 cm, to cover the most recent 3 months (44%), which in some cases was complemented by a further 3 cm to cover together 6 months (13%). The second most common sectioning pattern was the analysis of three sections of 1 cm each to cover the most recent 3 months (28%), when a more detailed evaluation of drug use pattern was relevant. Samples collected from other areas of the body such as axilla, pubic, chest, beard and leg, constituted 6% of the samples. The analysis of monthly sections plays an important role in the evaluation and interpretation of drug use, particularly in certain Medico-Legal cases. The sectors with the highest rates of positive results were Police (Forensics) (78%), Medico-Legal (62%) and Clinical (54%). The common drugs in each group were cannabinol (27%), cocaine (25%), morphine (17%), amphetamine (13%) and diazepam (15%). The positive rate for the Workplace sector was 10%. The most common drugs detected in the Workplace samples in each group were: THC (4%), codeine (2%), cocaine (2%), MDMA (0.5%) and diazepam (0.1%). The concentration levels of drugs found in samples from the workplace were lower than in the other sectors (95% of cases). The exceptions were for dihydrocodeine and MDMA, where levels were 170 and 143% higher, respectively. However, the maximum levels detected in the Workplace samples were lower. The Medico-Legal sector is the most prevalent sector using hair analysis in the UK but the rate of Workplace sector use of hair testing is increasing. One in 10 workplace hair tests detected the presence of at least one drug, which is twice the rate of detection using urine, which is a 1 in 20 urine sample. This means that the chances of identifying people on drugs in the workplace by testing hair samples are twice as likely than urine samples.     

Theoretical limits of the evaluation of drug concentrations in hair due to irregular hair growth

When examining concentration relationships of doses it must be taken into account that hair growth is irregular. Hair growing from the shaved skin after a single dose of a certain drug cannot possibly contain the same concentration as hair after the same dose that has not been cut over a long period. Concentrations can even change during the hair growth in cases where the hair had been cut a couple of months before the hair sample was taken. The variations in the expected concentrations can exceed 20%. On the other hand, the evaluation of a hair tuft which has grown after the last drug consumption may be important in forensic cases where the hair which has grown earlier is not available. This may lead to misinterpretations at low concentrations. Expected concentrations are calculated assuming a telogen part of 10%.     

Pesticide levels in head hair samples of Cretan population as an indicator of present and past exposure

In the present work we assessed chronic exposure of different working population groups of Messara and Sitia districts, Crete, Greece, to common currently used pesticides (diazinon, fenthion, methyl parathion and malathion) and two banned pesticides hexachlorocyclohexane (HCH) and DDT. The study population (211 persons, 110 females and 101 males) was divided to three groups; people working in greenhouses, animal breeders and people working in open cultivations. Methanolic extraction of pulverized hair was used for organophosphate pesticides extraction, followed by liquid-liquid extraction with water-ethyl acetate as a clean up step. The extraction of organochlorine pollutants was performed by acidic hydrolysis of the hair matrix followed by liquid-liquid and solid phase extraction. The levels of the aforementioned pesticides were measured by GC-ECD and gas chromatography-mass spectrometry (GC-MS). The median concentrations of a-HCH, HCB, lindane, opDDE, ppDDE, opDDD, ppDDD + opDDT and ppDDT were determined at 7.2, 2.2, 70.2, 2.7, 5.7, 3.1, 2.6 and 23.2 pg/mg. The median concentration of total HCHs and DDTs detected in the three working groups were: 95.0 and 8.9 pg/mg for the greenhouse workers, 38.2 and 3.3 pg/mg for the animal breeders and 24.1 and 5.2 pg/mg for the open cultivation group. Ten head hair samples were positive for diazinon at a mean concentration of 2.8 pg/mg. Fenthion, methyl parathion and malathion were not detected. Our results demonstrated the ability to assess chronic human past pesticides exposure, offering valuable information to epidemiological clinical studies.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29–316 ng/mg of hair for cocaine, 0.43–141 ng/mg of hair for benzoylecgonine and 0.93–1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

Detection and diagnostic interpretation of amphetamines in hair

A review with 22 references on detection and incorporation of amphetamines in hair is presented. This review deals with the detection, incorporation into hair, behavior in the hair shaft, confirmation of past drug use and diagnosis of dependence mainly regarding amphetamine and methamphetamine, along with methoxyphenamine, methylenedioxymethamphetamine, bromomethamphetamine, deprenyl, benzphetamine, fenproporex and mefenorex. First, pretreatment, extraction and analytical methods for amphetamines in hair using immunoassay, HPLC and GC/MS are discussed. This is followed by sections describing the animal experiments, incorporation rates of amphetamines from blood to hair and relationship between drug history and drug distribution in hair. Finally, the diagnosis of amphetamine dependence and confirmation of methamphetamine baby by hair analysis is discussed. The paper concludes with a brief outlook.     

Interlaboratory comparison of quantitative determinations of drug in hair samples

Testing human hair for drugs of abuse is a relatively new technique which requires control before being fully accepted in Justice applications. A consensus procedure was recently proposed to the four French Laboratories performing hair analysis for opiates and cocaine. Results of two independent controls have shown that the laboratories have performed very well quantitatively, using the recommended method. In order to compare these results with those obtained by other procedures, one sample was sent to 15 laboratories concerned with the analysis of human hair for drugs of abuse in Germany, Italy, Spain, and United States. Results from this study have indicated that the French recommended method is in accordance with the general procedures.     

Application of discriminant analysis to differentiate between incorporation of cocaine and its congeners into hair and contamination

The requirement to differentiate between incorporation and external contamination of drugs into hair is undisputed, in particular when dealing with compounds which are administered by sniffing or inhalation (e.g. cocaine). With the aim of making this discrimination, hair samples from cocaine (COC) users (group IN) and seized cocaine samples (group OUT) were compared regarding the parameters benzoylecgonine (BZE), ecgonine methyl ester (EME), ecgonine (ECG), anhydroecgonine methyl ester (AEME), cocaethylene (CE) and norcocaine (NCOC). Since most of these compounds may be minor by-products of COC or be formed by biotransformation or chemical degradation, the stability of each substance was carefully examined. COC was found to be converted into significant amounts of BZE, EME and ECG even under mild extraction conditions, while traces of NCOC proved to be a ubiquitous by-product of COC. Cocaine positive hairs and seized cocaine samples (diluted to relevant concentrations) were equally preprocessed and analyzed by LC-MS-MS. Out of the metabolites listed above, NCOC, CE and AEME (each normalised to COC) were significantly increased in the incorporation group (i.e. hair samples from cocaine users). Based on this approach, a statistical discriminant analysis enabled us to make a prediction (and estimation of uncertainty) for each cocaine positive hair sample as to its likelihood of belonging to the group of cocaine users or of being contaminated.     

Distribution of methamphetamine and amphetamine in drug abusers’ head hair

In order to aid the interpretation of hair results from methamphetamine (MA) abusers the MA and amphetamine (AP) concentrations in 2070 hair samples were statistically evaluated. The MA and AP concentrations in hair were put into three groups arbitrarily representing low, medium and high ranges and the metabolite-to-parent drug ratios of each group were examined. The concentration ranges proposed here were also applied to the interpretation of five authentic cases. The low, medium and high ranges of MA were 0.5–4.2, 4.2–24.5 and 24.5–608.9 ng/mg and those of AP were 0.1–0.4, 0.4–1.7 and 1.7–41.4 ng/mg. The AP-to-MA ratios showed large variation but a tendency that it decreased as the MA ranges increased. This evaluation was very useful to presume the severity of individuals’ MA abuse and to provide law enforcement agencies more understandable information. It could also facilitate the court's decision regarding specific circumstances surrounding the drug-related crimes.     

Simultaneous quantification of opiates, cocaine and cannabinoids in hair

The present paper describes a sensitive method developed in our laboratory for the simultaneous analysis of opiates (morphine, codeine and monoacetylmorphine), cocainics (cocaine and benzoylecgonine) and cannabinoids (Δ⁹-tetrahydrocannabinol and 11-nor-Δ⁹-tetrahydrocannabinol-9-carboxylic acid) in hair samples. After decontaminating the sample with dichloromethane, two consecutive hydrolyses were performed in order to achieve the best conditions for extracting the three kinds of drugs from the protein matrix. First the opiate and cocainic compounds were extracted by means of a soft acidic hydrolysis with 0.1 N HCl at 50 °C overnight and organic solvent extraction at pH 9.2. The cannabinoids need a stronger basic hydrolysis with 11.8 N KOH for 10 min at laboratory temperature. After adding maleic acid, the cannabinoids were extracted with an organic solvent. The derivatization was carried out with heptafluorobutyric anhydride and hexafluoropropanol. Calibration curves were linear between 0.5–100 ng/mg of hair. Recovery and reproducibility were assured. The quantification limits ranged between 0.04–0.26 ng/mg of hair. Seventy hair samples from known drug abusers were cut into 1-cm segments and analyzed by this method. The ranges of measured concentrations (ng/mg) were 0.31–89 for cocaine, 0.1–5.76 for benzoylecgonine, 0.34–45.79 for morphine, 0.45–39.59 for codeine, 0.09–48.18 for monoacetylmorphine, 0.06–7.63 for THC and 0.06–3.87 for THC---COOH. The results of sectional analyses agreed with the self reported drug histories. The usefulness of this method is in assessing earlier drug consumption, and also at the same time obtaining a chronological profile of the consumption of these three types of drugs.     

Analytical procedures for determination of opiates in hair: a review

This article reviews the analysis of opiates in hair. Hair matrix pretreatment, hydrolysis, extraction and detection procedures are presented amongst a study of over 70 bibliographic data. In addition, a new method for the extraction of opiates from hair, in which a powdered sample of hair is extracted directly by subcritical fluid, is presented.     

Segmental hair analysis for cocaine and heroin abuse determination

Segmental hair analysis was performed to obtain information about the history of drug abuse of subjects in a rehabilitation programme. The analytical data from hair samples were correlated, when possible, with urine analysis and to toxicological anamnesis. Toxicological analysis of hair seems to be a valid tool in this specific field.     

Hair analysis for cocaine: Factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Hair samples were contaminated by rubbing with cocaine (COC) followed by sweat application, multiple shampoo treatments and storage. The samples were then washed with isopropanol for 15 min, followed by sequential aqueous washes totaling 3.5 h. The amount of drug in the last wash was used to calculate a wash criterion to determine whether samples were positive due to use or contamination. Analyses of cocaine and metabolites were done by LC/MS/MS. These procedures were applied to samples produced by a U.S. government-sponsored cooperative study, in which this laboratory participated, and to samples in a parallel in-house study. All contaminated samples in both studies were correctly identified as contaminated by cutoff, benzoylecgonine (BE) presence, BE ratio, and/or the wash criterion. A method for determining hair porosity was applied to samples in both studies, and porosity characteristics of hair are discussed as they relate to experimental and real-world contamination of hair, preparation of proficiency survey samples, and analysis of unknown hair samples.     

Deposition of cannabinoids in hair after long-term use of cannabis

Hair analysis has shown great potential in the detection and control of drug use. Whether an assay is of quantitative value roughly corresponding to the amount of drug consumed, is still a matter of debate. The present investigation was aimed at a possible relationship between the cannabinoid concentration in hair and the cumulative dose in regular users of cannabis. Hair samples from the vertex region of the scalp were obtained from 12 male regular users of cannabis, and 10 male subjects with no experience of cannabis served as controls. None of the subjects had his hair permed, bleached or colored. Cannabis users provided information on drug use such as the current cannabis dose per day, the cumulative cannabis dose of the last 3 months, as well as the frequency of cannabis use during the last year. The concentration of delta-9-tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD) in hair was determined using gas chromatography-mass spectrometry. Cannabinoids were present in any hair sample of cannabis users, but were not detectable in control specimens. An increase in the amount of cannabinoids in hair with increasing dose was evident. The concentration of major cannabinoids (sum of THC, CBD and CBN) was significantly correlated to either the reported cumulative cannabis dose during the last 3 months or to the cannabis use during the last 3 months estimated from the daily dose and the frequency per year (r=0.68 or 0.71, p=0.023 or 0.014). A significant relationship between THC and the amount of cannabis used could not be established. As a conclusion, the sum of major cannabinoids in hair of regular users may provide a better measure of drug use than THC.     

A research note: the outcome of GC/MS/MS confirmation of hair assays on 93 cannabinoid (+) cases

This article reports the outcome of gas chromatography/tandem mass spectrometry confirmations for THC and carboxy-THC on 93 hair samples screened by RIA for cannabinoids. The samples were taken from probationers in Pinellas County, FL, who voluntarily provided the research staff with six hair and six urine specimens, collected at 1-month intervals. There were 40 samples that were RIA (+), urinalysis (−). Samples were selected which had cannabinoid (+) outcomes for hair, urine, or both. The THC and/or the carboxy-THC was (+) on confirmation. Of these 40 samples, 22 were (+) for both THC and carboxy-THC, 15 were (+) for THC but not carboxy-THC, and three were carboxy THC (+), but THC (−). Only one sample had a (+) RIA, but was (−) for both THC and carboxy-THC on confirmation. RIA detection of cannabinoids was confirmed in nearly all cases. Most cases that were RIA (−) but urine (+) were cannabinoid (+) when analyzed by GC/MS/MS.     

测定单根毛发中吗啡含量的放射免疫方法

目的 建立测定单根毛发中吗啡含量的放免方法。方法 用卵清蛋白-琥珀酰吗啡作免疫原,免疫新西兰白兔获得高品质抗血清;HPLC纯化~(125)Ⅰ-吗啡,建立放射免疫方法,测定正常人和吸毒人员单根毛发。结果 抗体亲和常数为3.25×10~(11)L/M,放化纯度为95％,比放射性112μCi/μg;方法的灵敏度为0.01ng/ml。对5例正常人及5例戒毒所吸毒人员的单根毛发进行了检测。单根毛发长度9～24cm,重量为0.7～2.1mg,5例正常人测值为1.75±0.37ng/mg(x±s);5例吸毒人员测值为471±204ng/mg(x±s)。结论 所建方法可准确定量单根毛发中吗啡的含量。     

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。     

Ethyl glucuronide: unusual distribution between head hair and pubic hair

Ethyl glucuronide (EtG) is a minor metabolite of ethanol that can be detected in hair. In some specific situations, head hair can be missing, and therefore, alternative anatomical locations of hair are of interest. In this study, paired hair specimens (head hair and pubic hair) from eight social drinkers were analyzed for EtG. Each sample was decontaminated by two dichloromethane bathes (5 ml) for 2 min. After cutting into small pieces, about 50 mg of hair was incubated in 2 ml water in the presence of 10 ng of EtG-d5, used as internal standard and submitted to ultra-sonication for 2 h. The aqueous phase was extracted by SPE using Oasis MAX columns. The hair extract was separated on an ACQUITY BEH HILIC column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 221-85 and 75 and m/z 226-75 for EtG and the IS, respectively. This laboratory is using a positive cut-off at 50 pg/mg. All eight head hair specimens were negative for EtG at a limit of quantitation fixed at 10 pg/mg. Surprisingly, EtG was identified at high concentrations in pubic hair, in the range 12-1370 pg/mg. It appears, therefore, that it is not possible to document the drinking status of a subject by simply switching from head hair to pubic hair.     

Investigating the morphology and genetics of scalp and facial hair characteristics for phenotype prediction

Microscopic traits and ultrastructure of hair such as cross-sectional shape, pigmentation, curvature, and internal structure help determine the level of variations between and across human populations. Apart from cosmetics and anthropological applications, such as determining species, somatic origin (body area), and biogeographic ancestry, the evidential value of hair has increased with rapid progression in the area of forensic DNA phenotyping (FDP). Individuals differ in the features of their scalp hair (greying, shape, colour, balding, thickness, and density) and facial hair (eyebrow thickness, monobrow, and beard thickness) features. Scalp and facial hair characteristics are genetically controlled and lead to visible inter-individual variations within and among populations of various ethnic origins. Hence, these characteristics can be exploited and made more inclusive in FDP, thereby leading to more comprehensive, accurate, and robust prediction models for forensic purposes. The present article focuses on understanding the genetics of scalp and facial hair characteristics with the goal to develop a more inclusive approach to better understand hair biology by integrating hair microscopy with genetics for genotype-phenotype correlation research.     

Influence of bleaching on the enantiomeric disposition of amphetamine-type stimulants in hair

The aim of this work was to study the influence of hair bleaching on the enantiomeric ratios of amphetamine-type stimulants (ATS), including amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyethylamphetamine. Hair specimens from 14 STA users were treated with a commercial bleaching product during 40 min. After alkaline digestion and solid-phase extraction of bleached and non-bleached hair, the STA enantiomers were derivatised with an in-house synthesised chiral reagent, the (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride. The diastereoisomers were quantified by GC/MS-NCI. The results showed that the concentrations of all enantiomers decreased in bleached hair in comparison with the non-treated hair (median values between 20 and 39%). The enantiomeric ratios of the STA in bleached hair were not significantly different from those determined in non-treated hair. Our findings pointed out that bleaching treatments decrease concentrations of STA in hair without influencing their enantiomeric ratios.