Effect of pigmentation on the drug deposition in hair of grey-haired subjects

A meta-analysis highlighting the increasing relevance of the hair matrix in exposure assessment to organic pollutants

Owing to a wide range of advantages, such as stability, non-invasiveness, and ease of sampling, hair has been used progressively for comprehensive biomonitoring of organic pollutants for the last three decades. This has led to the development of new analytical and multi-class analysis methods for the assessment of a broad range of organic pollutants in various population groups, ranging from small-scale studies to advanced studies with a large number of participants based on different exposure settings. This meta-analysis summarizes the existing literature on the assessment of organic pollutants in hair in terms of residue levels, the correlation of hair residue levels with those of other biological matrices and socio-demographic factors, the reliability of hair versus other biomatrices for exposure assessment, the use of segmental hair analysis for chronic exposure evaluation and the effect of external contamination on hair residue levels. Significantly high concentrations of organic pollutants such as pesticides, flame retardants, polychlorinated biphenyls and polycyclic aromatic hydrocarbon were reported in human hair samples from different regions and under different exposure settings. Similarly, high concentrations of pesticides (from agricultural activities), flame retardants (E-waste dismantling activities), dioxins and furans were observed in various occupational settings. Moreover, significant correlations (p < 0.05) for hair and blood concentrations were observed in majority of studies featuring pesticides and flame retardants. While among sociodemographic factors, gender and age significantly affected the hair concentrations in females and children in general exposure settings, whereas adult workers in occupational settings. Furthermore, the assessment of the hair burden of persistent organic pollutants in domestic and wild animals showed high concentrations for pesticides such as HCHs and DDTs whereas the laboratory-based studies using animals demonstrated strong correlations between exposure dose, exposure duration, and measured organic pollutant levels, mainly for chlorpyrifos, diazinon, terbuthylazine, aldrin, dieldrin and pyrethroid metabolites. Considering the critical analysis of the results obtained from literature review, hair is regarded as a reliable matrix for organic pollutant assessment; however, some limitations, as discussed in this review, need to be overcome to reinforce the status of hair as a suitable matrix for exposure assessment.

Adsorption of Diclofenac and PFBS on a Hair Keratin Dimer

Environmental pollution by man-made toxic and persistent organic compounds, found throughout the world in surface and groundwater, has various negative effects on aquatic life systems and even humans. Therefore, it is important to develop and improve water treatment technologies capable of removing such substances from wastewater and purifying drinking water. The two substances investigated are the widely used painkiller diclofenac and a member of the class of "forever chemicals", perfluorobutanesulfonate. Both are known to have serious negative effects on living organisms, especially under long-term exposure, and are detectable in human hair, suggesting adsorption to a part of the hair fiber complex. In this study, a human hair keratin dimer is investigated for its ability to absorb diclofenac and perfluorobutanesulfonate. Initial predictions for binding sites are obtained via molecular docking and subjected to molecular dynamics simulations for more than 1 μs. The binding affinities obtained by the linear interaction energy method are high enough to motivate further research on human hair keratins as a sustainable, low-cost, and easily allocatable filtration material.

Concentrations of citalopram and escitalopram in postmortem hair segments

Hair analysis can provide information regarding previous drug intake and use patterns, as the drugs consumed are incorporated into the hair. Therefore, reference values for drugs in hair are valuable in forensic investigations, especially when evaluating drug intake and assessing drug tolerance. The aim of the study was to determine concentrations of citalopram, escitalopram, and their primary metabolites in hair segments from deceased individuals with mental illness. Concentrations in up to six months prior to death were evaluated and compared with the estimated daily doses. Hair samples collected from 47 deceased individuals, were segmented in one to six 1 cm segments, and extracted overnight in medium. The concentrations in hair were quantified via ultra-high-performance liquid chromatography-tandem mass spectrometry. Following this quantification, the extracts were reanalyzed qualitatively using a chiral method to distinguish between citalopram and escitalopram intake. We found hair concentrations (10-90 percentile (perc.)) of citalopram from 0.12 to 67 ng/mg with a median of 8.2 ng/mg (N = 40 individuals, n = 182 segments) and of escitalopram from 0.027 to 7.0 ng/mg with a median of 3.9 ng/mg (N = 4, n = 23). The metabolite-to-drug ratios in hair (10-90 perc.) of citalopram were 0.091-0.57 with a median of 0.30 (N = 39) and of escitalopram were 0.053-0.63 with a median of 0.41 (N = 3). No correlations were found between concentrations in the hair and the estimated daily dose. However, our results indicate higher concentrations in dark hair compared to light hair, given the estimated doses, and thus an influence of hair color on the results. A significant positive correlation was found between the concentration of citalopram in the proximal segment and the blood concentrations. The median R/S-ratio of citalopram in hair was 1.5 and was similar to previously reported ratios in blood. In the present study, we report concentrations of citalopram and escitalopram in postmortem hair and their relation to an estimated daily dose and thus contribute valuable information in forensic investigations.

Long-term monitoring of IOX4 in horse hair and its longitudinal distribution with segmental analysis using liquid chromatography/electrospray ionization Q Exactive high-resolution mass spectrometry for the purpose of doping control

IOX4, a hypoxia-inducible factor stabilizer, is classified as a banned substance for horses in both horse racing and equestrian sports. We recently reported the pharmacokinetic profiles of IOX4 in horse plasma and urine and also identified potential monitoring targets for the doping control purpose. In this study, a long-term longitudinal analysis of IOX4 in horse hair after a nasoesophageal administration of IOX4 (500 mg/day for three days) to three thoroughbred mares is presented for the first time for controlling the abuse/misuse of IOX4. Six bunches of mane hair were collected at 0 (pre), 1, 2, 3, and 6 month(s) post-administration. Our results showed that the presence of IOX4 was identified in all post-administration horse hair samples but no metabolite could be detected. The detection window for IOX4 could achieve up to 6-month post-administration (last sampling point) by monitoring IOX4 in hair. In order to evaluate the longitudinal distribution of IOX4 over six months, a validated quantification method of IOX4 in hair was developed for the analysis of the post-administration samples. Segmental analysis of 2-cm cut hair across the entire length of post-administration hair showed that IOX4 could be quantified up to the level of 1.84 pg/mg. In addition, it was found that the movement of the incorporated IOX4 band in the hair shaft over six months varied among the three horses due to individual variation and a significant diffusion of IOX4 band up to 10 cm width was also observed in the 6-month post-administration hair samples.

Concentrations of Antidepressants, Antipsychotics, and Benzodiazepines in Hair Samples from Postmortem Cases

Certain postmortem case constellations require intensive investigation of the pattern of drug use over a long period before death. Hair analysis of illicit drugs has been investigated intensively over past decades, but there is a lack of comprehensive data on hair concentrations for antidepressants, antipsychotics, and benzodiazepines. This study aimed to obtain data for these substances. A LC-MS/MS method was developed and validated for detection of 52 antidepressants, antipsychotics, benzodiazepines, and metabolites in hair. Hair samples from 442 postmortem cases at the Institute of Legal Medicine of the Charité-University Medicine Berlin were analyzed. Postmortem hair concentrations of 49 analytes were obtained in 420 of the cases. Hair sample segmentation was possible in 258 cases, and the segments were compared to see if the concentrations decreased or increased. Descriptive statistical data are presented for the segmented and non-segmented cases combined (n = 420) and only the segmented cases (n = 258). An overview of published data for the target substances in hair is given. Metabolite/parent drug ratios were investigated for 10 metabolite/parent drug pairs. Cases were identified that had positive findings in hair, blood, urine, and organ tissue. The comprehensive data on postmortem hair concentrations for antidepressants, antipsychotics, and benzodiazepines may help other investigators in their casework. Postmortem hair analysis results provide valuable information on the drug intake history before death. Pattern changes can indicate if drug intake stopped or increased before death. Results should be interpreted carefully and preferably include segmental analysis and metabolite/parent drug ratios to exclude possible contamination.

Endogenous steroid hormones in hair: Investigations on different hair types, pigmentation effects and correlation to nails

Steroid hormone analysis is widely used in health- and stress-related research to get insights into various diseases and the adaption to stress. Hair analysis has been used as a tool for the long-term monitoring of these steroid hormones. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous identification and quantification of seven steroid hormones (cortisone, cortisol, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, progesterone) in hair. Cortisol, cortisone, androstenedione, testosterone and progesterone were detected and quantified in authentic hair samples of different individuals. Significantly higher concentrations for body hair were found for cortisone and testosterone compared to scalp hair. Furthermore, weak correlations for the majority of steroids between scalp and body hair indicate that body hair is not really suitable as alternative when scalp hair is not available. The influence of hair pigmentation was analyzed by comparing pigmented to non-pigmented hair of grey-haired individuals. The results showed no differences for cortisol, cortisone, androstenedione, testosterone and progesterone concentrations (p > 0.05) implying that hair pigmentation has not a strong effect on steroid hormone concentrations. Correlations between hair and nail steroid levels were also studied. Higher concentrations of cortisol and cortisone in hair were found compared to nails (p < 0.0001). No significant correlation for cortisone, cortisol, androstenedione, testosterone and progesterone concentrations were found between hair and nails. These results demonstrate that matrix-dependent value ranges for hair and nail steroid levels should be established and applied for interpretation.

Distribution pattern of common drugs of abuse, ethyl glucuronide, and benzodiazepines in hair across the scalp

While hair analysis is important and accepted in forensic applications, fundamental knowledge gaps still exist, exacerbated by a lack of knowledge of the incorporation mechanisms of substances into hair. The influence of the hair sampling location on the head on ethyl glucuronide (EtG) and cocaine concentrations was investigated by measuring the complete scalp hair of 14 (2 EtG, 4 cocaine, 8 both EtG and cocaine) study participants in a grid pattern for EtG, drugs of abuse, and benzodiazepines. Head skin perfusion and sweating rates were investigated to rationalize the concentration differences. For EtG, ratios between maximum and minimum concentrations on the scalp ranged from 2.5 to 7.1 (mean 4.4). For cocaine, the ratios ranged from 2.8 to 105 (mean 17.6). EtG concentrations were often highest at the vertex, but the distribution was strongly participant dependent. Cocaine and its metabolites showed the lowest concentrations at the vertex and the highest on the periphery, especially at the forehead. These differences led to hair from some head parts being clearly above conventional cut-offs and others clearly below. In addition to EtG and cocaine, the distributions of 24 other drugs of abuse and benzodiazepines/z-substances and metabolites are described. No clear pattern was observed for the head skin perfusion. Sweating rate measurements revealed higher sweating rates on the periphery of the haircut. Therefore, sweat could be a main incorporation route for cocaine. Concentration differences can lead to different interpretations depending on the sampling site. Therefore, the results are highly relevant for routine forensic hair analysis.

Segmental Analysis of Chlorprothixene and Desmethylchlorprothixene in Postmortem Hair

Analysis of drugs in hair differs from their analysis in other tissues due to the extended detection window, as well as the opportunity that segmental hair analysis offers for the detection of changes in drug intake over time. The antipsychotic drug chlorprothixene is widely used, but few reports exist on chlorprothixene concentrations in hair. In this study, we analyzed hair segments from 20 deceased psychiatric patients who had undergone chronic chlorprothixene treatment, and we report hair concentrations of chlorprothixene and its metabolite desmethylchlorprothixene. Three to six 1-cm long segments were analyzed per individual, corresponding to ~3-6 months of hair growth before death, depending on the length of the hair. We used a previously published and fully validated liquid chromatography-tandem mass spectrometry method for the hair analysis. The 10th-90th percentiles of chlorprothixene and desmethylchlorprothixene concentrations in all hair segments were 0.05-0.84 ng/mg and 0.06-0.89 ng/mg, respectively, with medians of 0.21 and 0.24 ng/mg, and means of 0.38 and 0.43 ng/mg. The estimated daily dosages ranged from 28 mg/day to 417 mg/day. We found a significant positive correlation between the concentration in hair and the estimated daily doses for both chlorprothixene (P = 0.0016, slope = 0.0044 [ng/mg hair]/[mg/day]) and the metabolite desmethylchlorprothixene (P = 0.0074). Concentrations generally decreased throughout the hair shaft from proximal to distal segments, with an average reduction in concentration from segment 1 to segment 3 of 24% for all cases, indicating that most of the individuals had been compliant with their treatment. We have provided some guidance regarding reference levels for chlorprothixene and desmethylchlorprothixene concentrations in hair from patients undergoing long-term chlorprothixene treatment.

Development and validation of an LC-MS/MS assay for the quantification of dolutegravir extracted from human hair

Measurement of drug concentrations in hair provides a non-invasive approach to assess drug adherence. Here, we report on the development and validation of a method for the quantification of the antiretroviral dolutegravir (DTG) extracted from human hair. DTG is extracted from hair samples by sonication and incubation in 50:50 methanol:acetonitrile with 2% formic acid overnight at 40 °C. Following extraction, samples are analyzed by reverse-phase chromatography on a Waters Atlantis T3 (50 × 2.1 mm, 3-μm particle size) column with subsequent detection by electrospray ionization in positive ion mode on an AB Sciex API-5000 triple quadrupole mass spectrometer. The stable, isotopically labeled ¹³C,d₅-DTG is used as an internal standard in the assay. The calibration range is 5-10,000 pg DTG/mL of extraction solvent with the ability to extract between 1 and 10 mg of hair/mL of extraction solvent. The assay was linear, accurate (inter-assay %bias within ± 6.5%), and precise (inter-assay %CV ≤ 10.3%). The assay was successfully used to analyze clinical samples from subjects on DTG regimens. Analysis of clinical samples suggested the potential presence of a degradation product, which was subsequently confirmed to occur with exposure to sunlight. The degradation of DTG could complicate absolute interpretation of clinical results, but the presence of this degradation product is easily evaluated with this assay to aid in data interpretation.

Hair analysis in toxicological investigation of drug-facilitated crimes in Denmark over a 8-year period

Hair can serve as a specimen for identifying past drug exposure. Segmental hair analysis may differentiate a single exposure from chronic use. Consequently, segmental hair analysis is useful for disclosing a single drug ingestion, as well as for determining repeated exposures in drug-facilitated crimes (DFCs). This paper presents an overview of toxicological investigations that have used hair analysis in DFC cases from 2009 to 2016 in Denmark. Hair concentrations were determined for 24 DFC-related drugs and metabolites, including benzodiazepines and other hypnotics, antihistamines, opioid analgesics, antipsychotics, barbiturates, and illicit drugs from DFC cases. Drug detection in hair in DFC cases following a single or few intakes of chlorprothixene, codeine, diphenhydramine, oxazepam, oxycodone, promethazine, and phenobarbital is reported for the first time in forensic toxicology. A literature review on concentrations in the published DFC-related hair cases and on concentrations in hair of these substances after single and multiple doses is included. These cases demonstrate the value of segmental hair analysis in DFCs and facilitate future interpretations of results.

Human Hair, Baltic Grey Seal (Halichoerus grypus) Fur and Herring Gull (Larus argentatus) Feathers as Accumulators of Bisphenol A and Alkylphenols

The purpose of the study was to determine the concentration of bisphenol A (BPA), 4-tert-octylphenol (OP), and 4-nonylphenol (NP), in human hair, the fur of Baltic grey seals and the feathers of herring gulls. Hair was collected from 42 volunteers, while grey seal fur (n = 17) came from the seal centre in Hel (Marine Station of Institute of Oceanography, University of Gdansk) and gull covert feathers (n = 26) were collected from dead herring gulls along the Southern Baltic coast. Assays of phenol derivatives were conducted using the high performance liquid chromatography with fluorescence detection technique. In human hair, the mean BPA concentration amounted to 411.2 ng g^-1 dw, OP 131.2 ng g^-1 dw, NP 4478.4 ng g^-1 dw, in seal fur BPA 67.5 ng g^-1 dw, OP 62.8 ng g^-1 dw, NP 39.1 ng g^-1 dw, and in feathers BPA 145.1 ng g^-1 dw, OP 162.0 ng g^-1 dw, NP 37.7 ng g^-1 dw. The increase of the analysed EDCs in hair was significantly influenced by diet rich in products of marine origin, as well as hair colouring, heating up food in plastic containers, using home cleaning products without protective gloves and wearing newly purchased clothes without washing them first. The concentration of phenol derivatives in seal fur was influenced solely by the uniform diet rich in fish. In birds, the feeding area during molting significantly influenced the concentration of BPA, OP and NP found in covert feathers.

Relationship between methamphetamine use history and segmental hair analysis findings of MA users

The aim of this study was to investigate the relationship between methamphetamine (MA) use history and segmental hair analysis (1 and 3cm sections) and whole hair analysis results in Korean MA users in rehabilitation programs. Hair samples were collected from 26 Korean MA users. Eleven of the 26 subjects used cannabis with MA and two used cocaine, opiates, and MDMA with MA. Self-reported single dose of MA from the 26 subjects ranged from 0.03 to 0.5g/one time. Concentrations of MA and its metabolite amphetamine (AP) in hair were determined by gas chromatography mass spectrometry (GC/MS) after derivatization. The method used was well validated. Qualitative analysis from all 1cm sections (n=154) revealed a good correlation between positive or negative results for MA in hair and self-reported MA use (69.48%, n=107). In detail, MA results were positive in 66 hair specimens of MA users who reported administering MA, and MA results were negative in 41 hair specimens of MA users who denied MA administration in the corresponding month. Test results were false-negative in 10.39% (n=16) of hair specimens and false-positive in 20.13% (n=31) of hair specimens. In false positive cases, it is considered that after MA cessation it continued to be accumulated in hair still, while in false negative cases, self-reported histories showed a small amount of MA use or MA use 5-7 months previously. In terms of quantitative analysis, the concentrations of MA in 1 and 3cm long hair segments and in whole hair samples ranged from 1.03 to 184.98 (mean 22.01), 2.26 to 89.33 (mean 18.71), and 0.91 to 124.49 (mean 15.24)ng/mg, respectively. Ten subjects showed a good correlation between MA use and MA concentration in hair. Correlation coefficient (r) of 7 among 10 subjects ranged from 0.71 to 0.98 (mean 0.85). Four subjects showed a low correlation between MA use and MA concentration in hair. Correlation coefficient (r) of 4 subjects ranged from 0.36 to 0.55. Eleven subjects showed a poor correlation between MA use and MA concentration in hair. Correlation between MA use and MA concentration in hair of remaining one subject could not be determined or calculated. In this study, the correlation between accurate MA use histories obtained by psychiatrists and well-trained counselors and MA concentrations in hair was shown. This report provides objective scientific findings that should considerably aid the interpretation of forensic results and of the results of trials related to MA use.

Hair as an alternative matrix in bioanalysis

Alternative matrices are steadily gaining recognition as biological samples for toxicological analyses. Hair presents many advantages over traditional matrices, such as urine and blood, since it provides retrospective information regarding drug exposure, can distinguish between chronic and acute or recent drug use by segmental analysis, is easy to obtain, and has considerable stability for long periods of time. For this reason, it has been employed in a wide variety of contexts, namely to evaluate workplace drug exposure, drug-facilitated sexual assault, pre-natal drug exposure, anti-doping control, pharmacological monitoring and alcohol abuse. In this article, issues concerning hair structure, collection, storage and analysis are reviewed. The mechanisms of drug incorporation into hair are briefly discussed. Analytical techniques for simultaneous drug quantification in hair are addressed. Finally, representative examples of drug quantification using hair are summarized, emphasizing its potentialities and limitations as an alternative biological matrix for toxicological analyses.

The assessment of cortisol in human hair: associations with sociodemographic variables and potential confounders

To inform the future use of hair cortisol measurement, we have investigated influences of potential confounding variables (natural hair colour, frequency of hair washes, age, sex, oral contraceptive (OC) use and smoking status) on hair cortisol levels. The main study sample comprised 360 participants (172 women) covering a wide range of ages (1-91 years; mean = 25.95). In addition, to more closely examine influences of natural hair colour and young age on hair cortisol levels, two additional samples comprising 69 participants with natural blond or dark brown hair (hair colour sample) as well as 28 young children and 34 adults (young age sample) were recruited. Results revealed a lack of an effect for natural hair colour, OC use, and smoking status on hair cortisol levels (all p's >0.10). No influence of frequency of hair washes was seen for proximal hair segments (p = 0.335) but for the third hair segment indicating lower cortisol content (p = 0.008). We found elevated hair cortisol levels in young children and older adults (p < 0.001). Finally, men showed higher hair cortisol levels than women (p = 0.002). The present data indicate that hair cortisol measurement provides a useful tool in stress-related psychobiological research when applied with the consideration of possible confounders including age and sex.

Hair cortisol: a parameter of chronic stress? Insights from a radiometabolism study in guinea pigs

Measurement of hair cortisol has become popular in the evaluation of chronic stress in various species. However, a sound validation is still missing. Therefore, deposition of radioactivity in hair and excretion into feces and urine after repeated injection of (3)H-cortisol was studied in guinea pigs (n = 8). Each animal was given intraperitoneally 243.6 kBq (3)H-cortisol/day on 3 successive days. After the first injection, all voided excreta were collected for 3 days. After the second injection, hair was shaved off the animals' back and newly grown hair was obtained on day 7. Following methanol extraction, radiolabeled and unlabeled glucocorticoid metabolites (GCM) in fecal and hair samples were characterized by high-performance liquid chromatography (HPLC) and enzyme immunoassays (EIA). In feces, maximum radioactivity was reached 8 h (median) post each injection, whereas maxima in urine were detected in the first samples (median 2.5 h). Metabolites excreted into feces (13.3% ± 3.7) or urine (86.7%) returned nearly to background levels. HPLC of fecal extracts showed minor variation between individuals and sexes. In hair, small amounts of radioactivity were present. However, two EIAs detected large amounts of unlabeled GCM, including high levels at the position of the cortisol standard; radioactivity was absent in this fraction, demonstrating that (3)H-cortisol was metabolized. Furthermore, large amounts of immunoreactivity coinciding with a radioactive peak at the elution position of cortisone were found. These results show for the first time that only small amounts of systemically administered radioactive glucocorticoids are deposited in hair of guinea pigs, while measurement of large amounts of unlabeled GCM strongly suggests local production of glucocorticoids in hair follicles.

Bioanalytical issues in patient-friendly sampling methods for therapeutic drug monitoring: focus on antiretroviral drugs

Therapeutic drug monitoring is a way to pharmacokinetically guide drug therapy to assure a certain exposure to a drug when this exposure is related to treatment effectiveness or toxicity. Routinely, drug concentrations are measured in plasma obtained by venipuncture. However, venous sampling is difficult in some populations, such as neonates and patients suffering from phlebitis, and there may be logistical challenges, for example when nonhospital-based sampling is warranted (e.g., resource-limited settings). A proper bioanalytical method is crucial for measurements of drug level matrices suitable for patient-friendly drug monitoring. Special attention must be paid to bioanalytical methods in these patient-friendly matrices, since specific matrix-associated issues may have important implications. In this review, we will discuss these issues and give an overview of published bioanalytical methods with a focus on patient-friendly drug monitoring of antiretroviral drugs, where dried blood spots, hair and saliva have been the most important matrices for patient-friendly therapeutic drug monitoring. Furthermore, we will point out considerations for proper assay development and validation.

Hair cortisol concentration as a noninvasive measure of long-term stress in free-ranging grizzly bears (Ursus arctos): considerations with implications for other wildlife

Human-caused landscape change negatively affects the sustainability of many wildlife populations. In Alberta, Canada, grizzly bears ( Ursus arctos L., 1758) live in one of the most populated and heavily exploited landscapes in which the species survives. Long-term physiological stress in individual animals may be the predominant mechanism linking landscape change with impaired wildlife population health. Hair cortisol concentration has been validated as a biomarker of long-term stress in humans and domestic animals; however, limited work has examined factors that may affect its measurement or interpretation. We have measured cortisol in as few as five guard hairs of a grizzly bear and have identified factors influencing hair cortisol concentration in this species. Hair cortisol varies with hair type, body region, and capture method. It is not influenced by colour, age, sex, environmental exposure (18 days), or prolonged laboratory storage (>1 year) and does not vary along the length of the hair shaft. Recommendations for prudent use of hair cortisol analysis in grizzly bears are discussed with implications for the development of hair cortisol concentration as a tool to monitor long-term stress in other wildlife.

New trends in hair analysis and scientific demands on validation and technical notes

This review focuses on basic aspects of method development and validation of hair testing procedures. Quality assurance is a major issue in drug testing in hair resulting in new recommendations, validation procedures and inter-laboratory comparisons. Furthermore recent trends in research concerning hair analysis are discussed, namely mechanisms of drug incorporation and retention, novel analytical procedures (especially ones using liquid chromatography-mass spectrometry (LC-MS) and alternative sample preparation techniques like solid-phase microextraction (SPME)), the determination of THC-COOH in hair samples, hair testing in drug-facilitated crimes, enantioselective hair testing procedures and the importance of hair analysis in clinical trials. Hair testing in analytical toxicology is still an area in need of further research.

State of the art in hair analysis for detection of drug and alcohol abuse

Hair differs from other materials used for toxicological analysis because of its unique ability to serve as a long-term storage of foreign substances with respect to the temporal appearance in blood. Over the last 20 years, hair testing has gained increasing attention and recognition for the retrospective investigation of chronic drug abuse as well as intentional or unintentional poisoning. In this paper, we review the physiological basics of hair growth, mechanisms of substance incorporation, analytical methods, result interpretation and practical applications of hair analysis for drugs and other organic substances. Improved chromatographic-mass spectrometric techniques with increased selectivity and sensitivity and new methods of sample preparation have improved detection limits from the ng/mg range to below pg/mg. These technical advances have substantially enhanced the ability to detect numerous drugs and other poisons in hair. For example, it was possible to detect previous administration of a single very low dose in drug-facilitated crimes. In addition to its potential application in large scale workplace drug testing and driving ability examination, hair analysis is also used for detection of gestational drug exposure, cases of criminal liability of drug addicts, diagnosis of chronic intoxication and in postmortem toxicology. Hair has only limited relevance in therapy compliance control. Fatty acid ethyl esters and ethyl glucuronide in hair have proven to be suitable markers for alcohol abuse. Hair analysis for drugs is, however, not a simple routine procedure and needs substantial guidelines throughout the testing process, i.e., from sample collection to results interpretation.

Hair analysis for opiates: evaluation of washing and incubation procedures

Hair analysis of drugs of abuse has been a subject of interest from a clinical, social and forensic perspective for years because of the broad time detection window after intake in comparison to urine or blood. However, the correct and reliable interpretation of opiates findings in an authentic hair sample requires optimalisation and standardisation of decontamination and incubation procedures. Comparing various published methods, we have found some variability in them and no unequivocal recommended procedure for starting with a method directly. Therefore, various combinations of solvents, of various polarity, as washing solvents were tested for removing opiates from the external surface of real hair samples. The yields of opiates from these washings were compared with the yields from the interior of the hair matrix after digestion with various procedures. The opiates after digestion were cleaned up from resulting solution on extraction columns with mixed solid-phase and analysed by GC-MS in standard EI mode after silylation. The efficiencies of neutral (Söerensen buffer, pH 7.4), acid (0.1 M HCl) and basic (1 M NaOH) digestion of the hair matrix were evaluated and the relative recoveries for morphine, codeine, dihydrocodeine and hydrocodone were compared. As it is very problematic to imitate the reference hair sample with a specific amount of analytes incorporated inside, which can be used for calibration to get a close estimate of the quantities of analytes inside the solid authentic sample, the total digestion of a hair sample in basic medium was considered to be a very important reference basis for quantitative determinations. The ratios of hydrolysis of labile 6-acetylmorphine or acetylcodeine were tested and evaluated in practical routine conditions of acid or neutral digestion of hair. Comparing the three methods of incubation of authentic hair samples, the methods using 1 M NaOH or 0.1 M HCl yielded higher recoveries of total equivalents of morphine or codeine, whereas the incubation in Söerensen buffer allowed the reflection of real ratios of labile metabolites and/or parent compounds in an original sample. This method has been shown to be capable of detecting hydrocodone in hair with other opiates concomitantly and to indicate the drug abuse pattern of a person at various time intervals in the past.

Determination of ethyl glucuronide in human hair by SPE and LC-MS/MS

A method for the sensitive and selective determination of ethyl glucuronide (EtG) in hair has been developed using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Washed and cut hair segments were extracted by ultrasonication (3h, 50 degrees C) and the extracts were cleaned-up with aminopropyl SPE columns. LC-MS/MS analysis was performed using a polar-endcapped phenyl-hexyl-RP-phase with negative mode electrospray ionisation (ESI) using a triple quadrupole mass spectrometer (Sciex API 365) with a turboionspray source and post-column addition of acetonitrile for enhanced sensitivity. The MS/MS transitions monitored were m/z 221 -->75 for EtG and 226 -->75 for D(5)-EtG as an internal standard. The method was selective and sensitive, with a detection limit of 51 pg/mg hair at a signal-to-noise ratio of 3:1. The mean recovery was 96%, with an intra- and inter-day precision of less than 11.7% at a concentration of 200 pg/mg. The linearity was assessed in the range of 25-2000 pg/mg hair, with a correlation coefficient of 0.997. The method was successfully applied to 97 human hair samples which were taken at autopsies from persons with known alcoholism or were obtained from alcoholics who were hospitalized for ethanol withdrawal, from social drinkers and from children having not consumed any alcohol. Although, approximately two-third of the alcoholics showed EtG concentrations in hair of higher than 51 pg/mg (up to >4000 pg/mg), in one-third the EtG concentration was below the detection limit. However, only in one of five hair samples of "social drinkers", the EtG concentration was above the detection limit (51 pg/mg). No EtG has been detected in the hair of children. These investigations demonstrate that heavy alcohol consumption may be but not necessarily has to be detectable by EtG analysis in hair.

Eumelanin is a major determinant for 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) incorporation into hair of mice

Mice with different hair pigmentation were studied to evaluate the role of melanin in the incorporation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) into hair. Mice C57BL/6J-c2j/+ (white), C57BL/6J-Ay (yellow), C57L/J (grey), C57BR/cdJ (brown) and C57BL/6J (black) were dosed with PhIP: 7-9 days old (total amount: 0.006 or 0.58 mg/kg b.wt., for 4 days) and adults (total amount 50 mg/kg b.wt. during 8 weeks). Hair was collected either 30 days after the last PhIP administration (new-born mice) or 8 weeks after the first administration (adult mice). PhIP was incorporated into black hair to a greater extent than into brown, grey, yellow and non-pigmented hair. The concentration of PhIP in the hair of new-born mice exposed to 0.58 mg PhIP/kg b.wt. were (mean+/-S.D.): 328+/-135 (black), 134+/-41 (brown), 9.1+/-1.2 (yellow) and 5.2+/-1.4 (white) ng/g hair. The PhIP concentrations in the hair of adult mice exposed to 50 mg/kg b.wt. were: 4750+/-1449 (black), 810+/-235 (brown), 541+/-119 (grey), 35.5+/-4.6 (yellow) and 21.6+/-8.8 (white) ng/g, and the eumelanin hair concentration in the same animals decreased in a similar pattern. A linear relationship (r2= 1.00, P<0.0001) between the relative PhIP incorporation and the eumelanin concentration in hair was found.

Hair testing for drugs of abuse: evaluation of external cocaine contamination and risk of false positives

In some laboratories hair testing may be the main method for the evaluation of individual's drug history, however, compelling evidence supports the possibility that the presence of a small amount of drug in hair can derive from external contamination. The aim of the present study is to verify if a single external contamination with a small amount of cocaine will last sufficiently long to make a contaminated subject indistinguishable from active users, and if normal washing practices together with the decontamination procedures are sufficient to completely remove the external contamination. The results obtained using the decontamination methods suggested in literature demonstrate that significant concentrations of cocaine (>1 ng/mg) and moderate quantities of benzoylecgonine (generally <0.5 ng/mg) are still detectable up to 10 weeks after contamination. These results question the reliability of hair testing. In fact, even using the most sophisticated decontamination procedures it is not possible to distinguish a drug-contaminated subject from an active user. Thus, while a negative result excludes both chronic use and "contact" with drugs, a positive result cannot and must not be interpreted as a sure sign of drug addiction, but should be further confirmed by urine analysis.

Use of hair analysis for confirmation of self-reported cocaine use in users with negative urine tests

INTRODUCTION

Identification of cocaine use based on a urine test may miss many cases because of the short elimination half-life of the drug. Our objective was to verify the sensitivity of the cocaine hair test in admitted users.

PATIENTS AND METHODS

Admitted cocaine users (38), that were 18-70 years of age and reported to have refrained from using cocaine in the few days to months prior to the test, were compared to 10 controls who claimed never to have used cocaine. All had negative urine tests for cocaine and benzoylecgonine by thin-layer chromatography. Cocaine and benzoylecgonine were extracted from unwashed hair and tested by established immunoassays.

RESULTS

The hair test was positive in 37/38 cases (97%) and in none of the controls. There was significantly more cocaine in black hair than in brown or blonde hair per mg of cocaine dose reported to have been consumed, highlighting a potential bias when interpreting test results in individuals with dark hair. There was a statistically significant correlation between reported dose used and hair concentrations of cocaine.

DISCUSSION

The cocaine hair test appears to be highly sensitive and specific in identifying past cocaine use in the setting of a negative urine test.

Hair analysis for drugs of abuse XXI. Effect of para-substituents on benzene ring of methamphetamine on drug incorporation into rat hair

In order to study the effect of para-substituents on the benzene ring of methamphetamine on drug incorporation into hair from blood, the plasma AUCs and hair concentrations of 7 methamphetamines [methamphetamine(MA), p-hydroxymethamphetamine(OHMA), p-bromomethamphetamine (BMA), p-aminomethamphetamine (AMA), p-nitromethamphetamine (NMA), p-methoxymethamphetamine (MOMA) and 3,4-methylenedioxymethamphetamine (MDMA)] plus propylhexedrine(PHX) in DA rats was determined after intraperitoneal injection at 5 mg/kg, with single dose for the plasma AUC and 10 doses for the hair concentration. Drug incorporation rates into hair (ICRs) were calculated by dividing each hair concentration by each plasma AUC. Comparing the highest value (NMA) to the lowest one (OHMA), the ICR of NMA was 31.7 times larger than that of OHMA. Using the ICR of MA which has no substitute on the benzene ring as a base point, nitro, bromo, methylenedioxy, methoxy and amino groups raised the drug incorporation into rat hair in this order. On the other hand, hydroxy substitution showed a negative effect on the ICR. In comparison between the ICRs of MA and PHX, it was found that the benzene ring shows higher affinity to melanin and less lipophilicity than the cyclohexyl ring. Our results showed that there is a relatively strong effect of the functional groups on drug incorporation into hair. The combination of melanin affinity and lipophilicity are clearly correlated with their ICR.

Statistical examination of hair color as a potential biasing factor in hair analysis

We review eight different data sets in this paper for the purposes of assessing the possibility that reported color of hair can produce a systematic bias in the interpretation of hair assays. We review studies or data sets that include heroin and its metabolites, cocaine and its metabolites, MDMA and its analogs, and amphetamine and methamphetamine. The studies have utilized a variety of different degrees of color categorization, ranging from the simple dichotomy of brown and black, to a high of 12 categories. The mean number of categories reported approaches 6 (mean = 5.875). There are a total of 2791 data points in this analysis. We utilize two major statistical techniques for assessing significance; one-way analysis of variance, and Tukey's Honestly Significant Difference procedure. In circumstances were only dichotomous contrasts are possible, one-way analysis of variance is used. In contrasts involving three or more categorical groups, Tukey's procedure is used. In circumstances where the homogeneity of group variances is not sustained by the Levene statistic, we use the Tamahane procedure, allowing an assessment that assumes unequal variances. The analysis of this data fails to discern a significant color effect. We speculate that it may be that variance is large in many domains affecting analyte recovery from hair. In large groups these variations tend to regress towards a typical or mean value. Thus the data here show that while there are group or aggregate differences in these 'typical' values, they are not great when considered in relation to the within-group variations which exist for those values. It is our view that color may play a role in the accumulation of drugs in hair, however it is likely to account for only a very small part of the complex process of drug accumulation.

Fast analysis of drugs in a single hair

A new method for the fast screening of cocaine and 6-monoacetylmorphine (6-MAM) in a single hair, using gas chromatography/mass spectrometry (GC/MS), is described. The analyses are conducted in less than 10 min with minimal sample preparation. The novel method combines the ChromatoProbe direct sample introduction device for intrainjector thermal extraction, fast GC separation, a supersonic molecular beam GC/MS interface and hyperthermal surface ionization (HSI). The technique has been successfully employed for the detection of cocaine in as little as a 1-mm section of hair using selected ion monitoring (SIM). Unambiguous full scan mass spectra of cocaine and 6-MAM were obtained on a single hair for cocaine and heroin users, respectively. HSI was found to be almost 3 orders of magnitude more selective than electron impact ionization for cocaine compared with the major hair constituents, with a minimum detected concentration of approximately 10 ppb in the SIM mode. Results obtained for 12 drugs users showed full qualitative agreement with similar results using rigorous solvent extraction followed by electrospray-liquid chromatography/mass spectrometry analysis. However, quantitative studies showed only partial agreement. No false positives were observed for 10 drugs free subjects. This method enables fast drug monitoring along the hair length which permits time correlation studies.

Hair concentrations and self-reported abuse history of 20 amphetamine and ecstasy users

Hair samples of 20 volunteers of the techno-music scene, who more or less regularly consumed ecstasy tablets and speed and anonymously reported their abuse history, were analyzed in one to seven 3 cm segments for amphetamine (A), methamphetamine (MA), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethamphetamine (MDE) and N-methyl-1-(1,3-benzodioxol-5-yl)-2-butylamine (MBDB) by digestion in 1 M NaOH, subsequent extraction with C18 Bond Elut columns, derivatization with pentafluoropropionyl anhydride and GC/MS-SIM measurements using deuterated standards of A, MA, MDA and MDMA. The concentrations were in the regions 0.1 to 4.8 ng/mg for A (17 samples), 0.05 to 0.89 ng/mg for MDA (16 samples), 0.1 to 8.3 ng/mg for MDMA (16 samples), 0.12 to 15 ng/mg for MDE (13 samples) and 0.21 to 1.3 ng/mg for MBDB (2 samples). MA was not detected. For comparison the frequency and the concentration of these drugs in 124 different ecstasy tablets were determined by HPLC. The drug concentration in the hair segments were compared with the volunteers' reports. Despite the enormous interindividual differences qualitatively an increase of the total concentration of MDA, MDMA and MDE in the proximate 3 cm segments with increasing ecstasy abuse frequency during the last three month before sampling is recognized. In the individual comparison with the chronological consumer reports in most cases a longer interruption or a change of the abuse intensity is not clearly seen at the segment concentrations. As a reason the incorporation of the drugs from sweat into elder hair regions and the slow removal by washing are discussed.

Structural and concentration effects on the deposition of tricyclic antidepressants in human hair

In order to elucidate the possibility of a long-term compliance analysis the hair samples of 56 patients, who were under a permanent treatment with tricyclic antidepressants, were analyzed for amitriptyline, clomipramine, doxepine, imipramine and maprotiline as well as their nor-metabolites. The hair concentrations varied between 0.4 and 40 ng/mg with no strong difference between the five drugs. In comparison to the therapeutic plasma levels described in literature the nor-metabolites always accumulate less in hair than drugs. No correlation was found between the hair concentration and the daily dose. The investigation of the full hair length in 3-cm sections for several examples of all five drugs shows that they can be detected in normally kept hair at least 1 year after intake.