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Hydroxycocaines in hair were investigated with many hundreds of head and body hair samples. All samples were washed by a published extensive aqueous method prior to confirmation by LC-MS/MS. Concentrations, percent of cocaine, and ratios of para- and meta-hydroxycocaines to ortho-hydroxycocaine are presented. Hydroxycocaines as percent of cocaine did not appear to be affected by cocaine concentrations, but were shown to increase with cocaethylene concentrations. Stability of hydroxycocaines over a year of ambient storage was demonstrated. Ortho-hydroxycocaine was shown to be formed by exposure of cocaine-positive hair to peroxide, while para- and meta-hydroxycocaines were not. Presence of para- or meta-hydroxycocaine at > 0.05% of cocaine is proposed as indicating ingestion of cocaine. This indicator prevents black hair from being more likely interpreted as positive for ingestion than lighter colored hair., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: Currently, hair straightening has become a regular hair treatment for women but likewise for men. Several studies have shown that thermal straightening has an influence on the concentration of ethyl glucuronide and of drugs of abuse content in hair. Heat treatment of hair may decrease concentrations of cocaine (COC) and of cocaethylene (CE) in hair and increase concentrations of benzoylecgonine (BZE). The goal of this study was to evaluate the influence of thermal straightening on anhydroecgonine methyl ester (AEME), a known cocaine smoking marker, in hair., Method: 42 positive COC hair samples were treated in vitro with iron plates heated to 200°C. During this treatment one lock of hair was put sequentially 30 times in contact with a hair straightener during 2s, the other lock was not treated. The hair samples were analyzed by a validated GC/MS method for AEME, COC and its metabolites BZE, norcocaine (NC), ecgonine methyl ester (EME) and CE., Results: After treatment, a median increase of concentrations was observed for AEME (110.3%) and BZE (27.6%) whereas a median decrease was found for COC (56.9%), NC (46.7%), EME (33.3%) and CE (41.7%). The median BZE/COC ratio of 0.6 in not treated hair increased to 1.5 in treated hair., Conclusion: Regarding our in vitro results, AEME may be produced by thermal hair straightening. Therefore, the presence of AEME in hair should not be used as an irrefutable prove of cocaine smoking. Our study shows that for the interpretation of AEME results in hair, potential heat treatment of hair should be considered. A ratio BZE/COC higher 1 appears to be a good marker to identify thermal treatment of hair before collection. Finally, thermal straightening should be documented during hair collection and should also be considered for the interpretation of COC results in hair., (Copyright © 2019. Published by Elsevier B.V.)

Given that external contamination must be considered in hair analysis, there is still a demand for reliable tools to differentiate between incorporation of drugs into the hair as a result of drug consumption and of the hair shaft by external contamination. With the aim of establishing alternative discrimination parameters, some of the hydroxy metabolites of cocaine i.e., para- and meta-hydroxycocaine and para- and meta-hydroxybenzoylecgonine were measured together with cocaine, benzoylecgonine, cocaethylene, and norcocaine in five seized street cocaine samples and in hair samples from different cohorts: cohort 1 (in vivo external contamination study, n = 28), cohort 2 (individuals with self-reported cocaine use, n = 92), and cohort 3 (individuals with suspected cocaine use or contamination, n = 198). Statistical evaluation of the data of cohort 1 and 2 using ROC curves yielded metabolic ratios indicating cocaine use. Based on these results, a decision workflow was established for the discrimination between cocaine use and external contamination. The power of this approach was finally statistically validated across the different cohorts., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Over the last decade, hair analysis has become a routine procedure in most forensic laboratories and, complementary to blood and urine, hair is a unique biological matrix which gives the opportunity to establish a temporal consumption profile. Despite hair is widely used to identify drug use, environmental contamination continues to represent a challenging factor of this procedure, especially for cocaine (COC). In the last few years several strategies have been proposed in order to distinguish between actual use and external contamination, however the commonly detected COC metabolites probably are insufficient for demonstrating cocaine use through hair testing. Thus, the aim of this study is to develop an ultra high performance liquid cromatography - tandem mass spectrometry (UHPLC-MS/MS) method able to detect and quantify hydroxy-COC metabolites, as specific markers of COC abuse, in hair samples from COC consumers, thus enabling unambiguous evidence of COC consumption. At the beginning, since no commercial reference materials were available, COC-positive hair samples were tested using parent ion scan-based analysis to extract hydroxy COC metabolites target ions. Once identified, the reference materials were synthesized by our analytical laboratory allowing the development of the first UHPLC-MS/MS validated method to quantify p- and m-isomers of hydroxy COC, as well as hydroxy benzoylecgonine (BE) and hydroxy norcocaine (NCOC). The method was successfully applied to a large number of COC-positive hair samples and introduced into a routine procedure for testing drug ingestion in order to evaluate for the first-time hydroxy metabolites of COC ranges in hair and their correlation with COC and BE., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Hair analysis is a suitable way to discriminate between coca chewers and consumers of manufactured cocaine using the coca alkaloids hygrine (HYG) and cuscohygrine (CUS) as markers. In the present preliminary study it was examined whether CUS and HYG can be detected in hair of occasional and moderate coca chewers or coca tea drinkers, whether CUS and HYG appear in hair of PACO consumers (smoking coca paste waste), and whether anhydroecgonine methyl ester (AEME) is a useful cocaine smoking marker in this context., Method: Three groups were included: 10 volunteers from Buenos Aires with occasional or moderate chewing of coca leaves or drinking coca tea, 20 Argentinean PACO smokers and 8 German cocaine users. The hair samples (1-4 segments) were analyzed by a validated LC-MS/MS method for cocaine (COC), norcocaine (NC), benzoylecgonine (BE), ecgonine methyl ester (EME), cocaethylene (CE), cinnamoylcocaine (CIN), tropacocaine (TRO), AEME, CUS and HYG. For comparison, eight samples of coca leaves or coca tea were analyzed., Results: Only low concentrations of COC were found in hair of seven occasional users of coca leaves or coca tea (0.010-0.051 ng/mg). For three moderate chewers of coca leaves all compounds were detected including AEME but except TRO. The hair samples of PACO smokers contained much higher concentrations of COC (0.027-341 ng/mg, mean 37.4 ng/mg) and its metabolites. CUS was not found in these samples but traces of HYG were seen in 8 of 37 hair segments. AEME as a marker for coca smoking was detected in hair of 15 smokers. In comparison to COC, the concentrations of EME and CIN were higher for PACO smokers than for German cocaine consumers. AEME (56 ± 20 μg/g) was detected in all coca leave and coca tea samples which explains the detection of this substance in hair of coca chewers. Therefore, its use for differentiation between coca chewers and PACO smokers is limited., Conclusion: CUS remains to be the most suitable marker in hair for chewing coca leaves or drinking coca tea more frequently than two times per month since it does not appear in hair of Argentinean PACO smokers and German cocaine users. Contrary to a previous proposal, the ratios CIN/COC and EME/COC appeared not to be applicable as criteria for this purpose because of the higher concentration of these alkaloids in hair of PACO smokers. More research is needed to assess the value of AEME in hair of South American coca leave or cocaine users., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Drugs which are commonly smoked or sniffed (e.g. cocaine), can contaminate hair through smoke or dust; therefore testing for metabolites, especially hydroxy metabolites, is highly recommended. The presence of hydroxy metabolites in street-cocaine (COC) has been discussed. To check if detection of hydroxy metabolites definitely proves ingestion, the presence of these metabolites in street COC samples has to be checked. It is expected that the more hydrophilic hydroxy metabolites of COC are incorporated into the hair-matrix to a lesser extent. For this study 576 COC positive hair samples (≥0.1ng COC/mg hair) were analysed by LC-MS/MS for benzoylecgonine (BE), norcocaine (NC), cocaethylene (CE), ortho-, meta- and para-hydroxy COC (o-, m-, p-OH-COC), meta- and para-hydroxy BE (m-, p-OH-BE), and meta- and para-hydroxy NC (m-, p-OH-NC). The results were compared with the respective metabolite/COC concentration ratios in 146 street COC samples, confiscated by the Bavarian police. Peak areas were used to estimate BE/COC, NC/COC, CE/COC and hydroxy metabolites/COC. Similar metabolic ratios were found for o-OH-COC in 88% of the samples, but for p-OH-COC and m-OH-COC only in 5.1% and 6.8%, respectively. Notably, p- and m-OH-BE as well as p- and m-OH-NC could not be identified from seized samples. We propose that area ratios exceeding the ratios of street COC more than twice or identification of OH-BE and OH-NC enable to differentiate COC consumption from contamination. Using these criteria, consumption of the drug could be proven in 92% of COC positive samples. As detection of meta- and para-hydroxy metabolites using the above mentioned criteria is a reliable tool to distinguish between ingestion and external contamination, it is recommended to implement their measurement into daily routine work., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Despite having been extensively discussed over the last decade, the differentiation between systemic exposure and external contamination still continues to be one of the limitations of hair testing for drugs. For this reason, we consider it worthwhile to re-state some basic principles in this short review. Various studies investigating a diversity of wash protocols, most using artificially contaminated hair with cocaine, have been valuable in evaluating wash efficacy and in understanding the incorporation of drugs in hair. However, assessments of wash efficacy made with real hair samples, as opposed to artificially contaminated samples, provide a different perspective, and demonstrate how rarely external contamination affects the interpretation of results. Data from a large number of hair samples from crack cocaine users, confirmed the usefulness of our protocol to remove most of the externally deposited cocaine. The data showed that hair levels of cocaine and benzoylecgonine in crack cocaine users were overall high with ratio of benzoylecgonine to cocaine in all samples above 0.1. The wash residue concentrations of cocaine ranged from not detected to 21ng/mg with a median of 0.5ng/mg. Cocaine was detected in the wash residue in 105 out of 138 samples. The wash to hair cocaine ratio ranged from not detected to 0.36 with a median of 0.02. The wash to hair cocaine ratios were below 0.07 in 133 cases. The five cases that produced wash to hair ratios above 0.1, one sample was at 0.11, three at 0.13 and one at 0.36, possibly because these cases were at the lower end of cocaine levels, however, we could not rule out that the hair was contaminated. Whilst it is not possible to differentiate between the drug extracted from the hair and the drug attached to the outside of the hair, we can compare levels of drug in the wash residue with levels detected in the hair sample. In addition, further diagnostic criteria must be applied to minimise potential misdiagnosis of external contamination. When drugs are detected in hair, individuals have clearly been in an environment where drugs are present, but it is only on rare occasions that it is unclear whether this is the result of drug use or of external contamination, and, in those cases, the results of testing need to be interpreted in the light of corroborating evidence from clinical data or social context., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Hair testing is a recognized approach when it comes to accessing historical drug use. According to the World Drug Report of United Nations Office on Drugs and Crime (UNODC) 2015, Brazil is the largest cocaine (COC) market in South America. New analytical methodologies to detect crack/cocaine analytes in hair samples are highly desirable. Here, a method consisting of a liquid-phase microextraction (LPME) as a clean-up step, followed by gas chromatography-mass spectrometry (GC-MS) analysis has been proposed. The new validated method consisted of a washing step; an overnight incubation with methanol and a quick derivatization with butylchloroformate. Once derivatized, the samples were then submitted to the LPME procedure. Limits of detection (LoD) and quantitation (LoQ) obtained were of 0.1 and 0.5ng/mg for COC 0.4 and 0.5ng/mg for anhydroecgonine methyl ester (AEME); 0.03 and 0.05 for cocaethylene (CE), respectively and 0.05ng/mg for both LoD and LoQ for benzoylecgonine (BZE). All calibration curves were linear over the scope applied, from LoQ up to 20ng/mg, with a r 2 >0.99. Precision and accuracy assays showed acceptable %RSD values, according to international guidelines. Twelve postmortem head hair samples stemming from the Institute of Legal Medicine of Sao Paulo (IML-SP) have been analyzed, from which seven have shown to be positive for COC (0.75->20ng/mg) and BZE (0.1->20ng/mg). Apart from COC's main metabolite, four samples were also positive for CE (0.1-3.9ng/mg) and three samples for AEME (0.5-4.9ng/mg). To conclude, the LPME technique together with GC-MS analysis have shown promising results and were able to meet the demand of the laboratory of analyzing postmortem hair samples to look for all four analytes., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Even though hair analysis often seems to be the best choice for retrospective monitoring of cocaine intake, differentiating between incorporated cocaine and external contamination is widely debated. In this study we report results obtained in 90 hair samples from addicts. All samples were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, and tropococaine by gas chromatography-mass spectrometry (GC-MS) techniques coupled with direct immersion solid-phase micro-extraction. Cocaine concentrations were stratified into three classes of usage: light (0.5-3 ng/mg), moderate (3.1-10 ng/mg) and heavy (10.1-40 ng/mg). The Substance Abuse and Mental Health Services Administration cut-off criteria for establishing active cocaine use were applied to the results. For all samples criteria were cocaine levels above 0.5 ng/mg (ranging from 1.63 to 39.29 ng/mg, mean 9.49 ng/mg), benzoylecgonine concentrations ≥ 0.05 ng/mg (ranging from 0.19 to 5.77 ng/mg, mean 1.40), and benzoylecgonine to cocaine % ratio ≥5% (from 6.43 to 26.09%). Norcocaine was present in 58.9% of samples (concentration range: 0.22-3.14 ng/mg) and was strongly predictive only of heavy cocaine use (sensitivity 100% for cocaine concentrations above 9.58 ng/mg). Twenty hair samples from moderate and heavy users tested positive for cocaethylene (concentration range: 0.22-1.98 ng/mg, mean 0.73 ng/mg). This study on hair samples with no chance of false positive cases highlights the very limited applications of testing minor cocaine metabolites for definitive proof of active cocaine consumption. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd., (© 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd.)

Contrary to the illegal use of any form of manufactured cocaine, chewing of coca leaves and drinking of coca tea are allowed and are very common and socially integrated in several South American countries. Because of this different legal state, an analytical method for discrimination between use of coca leaves and abuse of processed cocaine preparations is required. In this study, the applicability of hair analysis for this purpose was examined. Hair samples from 26 Argentinean coca chewers and 22 German cocaine users were analysed for cocaine (COC), norcocaine (NC), benzoylecgonine (BE), ecgonine methyl ester (EME), cocaethylene (CE), cinnamoylcocaine (CIN), tropacocaine (TRO), cuscohygrine (CUS) and hygrine (HYG) by hydrophilic interaction liquid chromatography (HILIC) in combination with triplequad mass spectrometry (MS/MS) and hybrid quadrupole time-of-flight mass spectrometry (QTOF-MS). The following concentrations (range, median, ng/mg) were determined in hair of the coca chewers: COC 0.085-75.5, 17.0; NC 0.03-1.15, 0.12; BE 0.046-35.5, 6.1; EME 0.014-6.0, 0.66; CE 0.00-13.8, 0.38; CIN 0.005-16.8, 0.79; TRO 0.02-0.16, 0.023; CUS 0.026-26.7, 0.31. In lack of a reference substance, only qualitative data were obtained for HYG, and two metabolites of CUS were detected which were not found in hair of the cocaine users. For interpretation, the concentrations of the metabolites and of the coca alkaloids in relation to cocaine were statistically compared between coca chewers and cocaine users. By analysis of variance (ANOVA) significant differences were found for all analytes (α = 0.000 to 0.030) with the exception of TRO (α = 0.218). The ratios CUS/COC, CIN/COC and EME/COC appeared to be the most suitable criteria for discrimination between both groups with the means and medians 5-fold to 10-fold higher for coca chewers and a low overlap of the ranges between both groups. The same was qualitatively found for HYG. However, these criteria cannot exclude cocaine use in addition to coca chewing. In this regard screening for typical cutting agents can be helpful and led to the detection of levamisole (21×), lidocaine (6×) and paracetamol (3×) in the 22 samples from German cocaine users, whereas no levamisole, lidocaine (3×) and paracetamol (1×) were found in hair from the Argentinean coca chewers. These criteria have to be confirmed for South American cocaine consumers including smokers of coca paste and may be different because of different composition of the drug and other use habits.

Background: Because levamisole has been increasingly found as a component of illicit drugs, a robust method to detect its presence in hair samples is needed. However, no systematic research on the detection of levamisole in hair samples has been published. The method presented here uses direct immersion solid-phase microextraction coupled with gas chromatography and mass spectrometry (DI-SPME-GC/MS) to detect levamisole and minor cocaine congeners in hair samples using a single-extraction method., Methods: Fifty hair samples taken in the last 4 years were obtained from cocaine abusers, along with controls taken from drug-free volunteers. Sampling was performed using direct immersion with a 30-μm polydimethylsiloxane fused silica/stainless steel fiber. Calibration curves were prepared by adding known amounts of analytes and deuterated internal standards to the hair samples taken from drug-free volunteers. This study focused on the adulterant levamisole and some minor cocaine congeners (tropococaine, norcocaine, and cocaethylene)., Results: Levamisole was detected in 38% of the hair samples analyzed; its concentration ranged from 0.2 to 0.8 ng/mg. The limit of quantification and limit of detection for levamisole, tropococaine, norcocaine, and cocaine were 0.2 and 0.1 ng/mg, respectively., Conclusions: DI-SPME-GC/MS is a sensitive and specific method to detect the presence of levamisole and cocaine congeners in hair samples.

Samples from a self-proclaimed cocaine (COC) user, from 19 drug users (postmortem) and from 27 drug chemists were extensively washed and analyzed for COC, benzoylecgonine, norcocaine (NC), cocaethylene (CE) and aryl hydroxycocaines by liquid chromatography-tandem mass spectrometry. Published wash criteria and cutoffs were applied to the results. Additionally, the data were used to formulate new reporting criteria and interpretation guidelines for forensic casework. Applying the wash and reporting criteria, hair that was externally contaminated with COC was distinguished from hair collected from individuals known to have consumed COC. In addition, CE, NC and hydroxycocaine metabolites were only present in COC users' hair and not in drug chemists' hair. When properly applied, the use of an extended wash, along with the reporting criteria defined here, will exclude false-positive results from environmental contact with COC., (Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Today, forensic hair analysis is considered to be a standard method for identifying chronic drug users since information about drug use stored and located in hair can cover several months to even years. When interpreting these results, one should be aware of all kind of pitfalls. External factors such as bleaching might influence the analytical result. Although the effect of hydrogen peroxide on cocaine in a solution was described before, it was never investigated whether the described reaction products (ecgonine methylester, benzoylecgonine, hydroxynorcocaine and dihydroxycocaine) are indeed found on contaminated or user hair. Since it is of great importance in forensic hair analysis to know whether cocaine and/or reaction products are detectable in hair after bleaching, matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was used to study the effect of hydrogen peroxide treatment on incorporated cocaine in hairs. Cocaine oxidation products were identified in a solution based on MS/MS spectra and spatial distribution of these products in hair was explored using MALDI TOF-MS. All images were accomplished by spraying α-Cyano-4-hydroxycinnamic acid (CHCA) as a MALDI-matrix. Images revealed a loss of detectability of cocaine and its reaction products in hairs already after a short bleaching period. Since all compounds of interest are found in the hydrogen peroxide and wash solution, these findings indicate that all evidence of cocaine use might be lost after a hair bleaching treatment. Therefore, forensic toxicologists should take into consideration whether hair samples were bleached before making any conclusions from hair analysis results., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

In hair analysis, cocaine (COC) and its metabolites have been studied relatively extensively with a consistent focus of distinguishing active drug use and excluding external contamination. Although quantitative cut-offs using major metabolite, benzolecgonine (BE), in hair have been proposed to distinguish likely active use from passive exposure, exogenously formed BE may result in false positive tests. Hence, the presence of less commonly detected COC metabolite, norcocaine (NCOC), may be useful in increasing certainty of illicit COC use and evaluating likelihood of environmental contamination. The objective of the present study was to observe the pattern of NCOC detection in a clinical population of suspected users and evaluate the possible role of NCOC in distinguishing systemic exposure from external contamination to COC and assessing intensity of cocaine use. Hair samples collected between January 2011 and May 2013 from the Motherisk Laboratory were analyzed by GC-MS for the presence of COC, BE, and NCOC. NCOC positivity rates (%) for various COC concentration ranges as well as sensitivity, specificity, positive predictive value, and negative predictive values of NCOC as a biomarker of different COC use profiles was calculated. The rate of NCOC positivity (%) within COC concentration ranges (ng/mg) 0.13-0.4 (above LOD, below LOQ), 0.4-3, 3-6, 6-10, 10-14, >14 were 0.26, 4.15, 29.63, 55.85, 80.37, and 94.02, respectively; p<0.0001 for all positivity comparisons between ranges. These results were used to determine a COC cut-off concentration for differing levels of COC use. The presence of NCOC above the LOD of 0.13 ng/mg predicted COC concentrations exceeding 14.00 ng/mg, with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 94.0%, 87.9%, 41.5%, and 99.4%, respectively. The presence NCOC above the LOD of 0.13 ng/mg predicted COC concentrations exceeding the 75th percentile, with sensitivity, specificity, PPV, and NPV of 76.6%, 94.7%, 74.7%, and 95.2%, respectively. Despite an inability to definitively rule out external contamination, the presence of NCOC in hair is strongly associated with elevated COC levels and performs as a highly specific surrogate marker for frequent/intensive cocaine use and highly sensitive marker for intensive/daily use of cocaine., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: Toenails were assessed as an alternative matrix to hair for retrospective monitoring of cocaine consumption of recreational and dependent users. Results/methodology: Toenail clippings, scrapings and hair samples from recreational and dependent cocaine users were analyzed for cocaine and metabolites. Dependent users displayed significantly higher concentrations in hair and toenail samples compared to recreational users. Cocaine abstinence could be monitored in hair and toenail samples. One postmortem fingernail was analyzed in layers to investigate the cocaine and metabolite concentration profile. Highest concentrations were observed in the dorsal layer, being indicative of contamination., Conclusion: Having led to comparable results, toenails may be an alternative for retrospective monitoring of cocaine consumption/abstinence. Hair should remain the first choice for assessment of temporal evidence of drug intake.

In this study, a novel approach combining different techniques, including Fourier transform infrared (FT-IR) spectroscopy, photoacoustic spectroscopy (PAS) with an interferometric cantilever microphone, and principal component analysis (PCA) along with a proper data preprocessing procedure, have been used in the investigation of hair samples for cocaine abuse. Hair fibers from cocaine-overdose patients have been measured using a simple procedure involving cantilever-enhanced photoacoustic Fourier transform infrared spectroscopy. In addition, a reference group of hair samples from subjects with no cocaine abuse has been measured. We present a first approach to discriminate the cocaine users from the reference group with the photoacoustic method and PCA. With proper data preprocessing methods, the two groups were successfully separated according to their spectra. The results were confirmed with two different classification methods independent of the principal component data analysis.

Hair analysis is a useful tool in both clinical and forensic fields: it allows information about drugs of abuse (DOA) consumption to be obtained. However, in spite of analytical results, sometimes patients continue to deny using drugs or, on the contrary, insist on describing themselves as severe drug addicts; indeed there are often considerable difficulties in getting truthful statements about the real amount of drugs used. In this study we have tried to compare cocaine concentration in hair samples with self-reported drug intake. We enrolled 113 subjects (61 Africans, 52 Caucasians) who had been recently sent to jail. They were asked to tell about their use of illicit drugs during the last three months and then submitted to hair analysis. Hair segments (3 cm) were analyzed by GC-MS for amphetamines, cocaine and opiates. Useful data was obtained from 82 subjects, separated into two main groups on account of ethnic origin (African or Caucasian) and divided further into daily, weekly and monthly users. The results showed qualitative results and self-reported consumption to be in good agreement, although the correlation between frequency of consumption and concentration in hair revealed sometimes higher concentrations in contrast with the admission of low consumption. There was a definite separation between occasional and daily use (especially in Caucasian people), while concentrations found where weekly use was reported were more variable. Concentrations of cocaine measured in Africans' hair were much higher than in Caucasians'. Even if this study is exclusively based on self-report, it provides some interesting information in order to differentiate the frequency of consumption, and especially underlines the great importance of ethnic bias on hair analysis., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

A gas chromatography-mass spectrometry method for the determination of ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate in hair samples was developed, validated and applied to real samples. Ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate are fatty acid ethyl esters (FAEE) which are known to be direct biotransformation products of ethanol. Their presence in the body fluids and tissue is therefore indicative of alcohol intake and, in particular, FAEE concentration in hair higher than 0.5 ng/mg is indicative of excessive chronic alcohol consumption. The method was applied to 80 hair samples formerly found positive for cocaine and FAEE analytical results were compared with the presence of cocaethylene, a cocaine metabolite formed only when alcohol and cocaine are used together. According to our data the two biomarkers (FAEE and cocaethylene in hair) are tools of great value in the assessment of the diagnosis of use of cocaine and ethanol. In fact, discrepancies were noted and might be related to various factors including differences in consumption habits and thus permitting to distinguish the use of both substances non-concurrently or concurrently. Also, the determination of both markers may, in some cases, discriminate the use of moderate or heavy alcohol amounts when associated with cocaine. Finally, in a population of non-cocaine-users our results support FAEE as valuable means in the assessment of excessive alcohol chronic use., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Background: Preclinical and other research suggest that youth with prenatal cocaine exposure (PCE) may be at high risk for cocaine use due to both altered brain development and exposure to unhealthy environments., Methods: Participants are early adolescents who were prospectively enrolled in a longitudinal study of PCE prior to or at birth. Hair samples were collected from the youth at ages 10½ and 12½ (N=263). Samples were analyzed for cocaine and its metabolites using ELISA screening with gas chromatography/mass spectroscopy (GC/MS) confirmation of positive samples. Statistical analyses included comparisons between the hair-positive and hair-negative groups on risk and protective factors chosen a priori as well as hierarchical logistical regression analyses to predict membership in the hair-positive group., Results: Hair samples were positive for cocaine use for 14% (n=36) of the tested cohort. Exactly half of the hair-positive preteens had a history of PCE. Group comparisons revealed that hair-negative youth had significantly higher IQ scores at age 10½; the hair-positive youth had greater availability of cigarettes, alcohol, and other drugs in the home; caregivers with more alcohol problems and depressive symptoms; less nurturing home environments; and less positive attachment to their primary caregivers and peers. The caregivers of the hair-positive preteens reported that the youth displayed more externalizing and social problems, and the hair-positive youth endorsed more experimentation with cigarettes, alcohol, and/or other drugs. Mental health problems, peer drug use, exposure to violence, and neighborhood characteristics did not differ between the groups. Regression analyses showed that the availability of drugs in the home had the greatest predictive value for hair-positive group membership while higher IQ, more nurturing home environments, and positive attachment to caregivers or peers exerted some protective effect., Conclusion: The results do not support a direct relationship between PCE and early adolescent experimentation with cocaine. Proximal risk and protective factors-those associated with the home environment and preteens' caregivers-were more closely related to early cocaine use than more distal factors such as neighborhood characteristics. Consistent with theories of adolescent problem behavior, the data demonstrate the complexity of predicting pre-adolescent drug use and identify a number of individual and contextual factors that could serve as important foci for intervention., (Copyright © 2010 Elsevier Inc. All rights reserved.)

In driver licence regranting, subjects with a history of cocaine use are requested to undergo laboratory testing to verify both current and past abstinence from the drug. Identification of cocaine use based only on urinalysis may miss some cases because of the short elimination half-life of the drug. Moreover, many abusers know how to time their cocaine consumption in such a way that they can "beat" the urinalysis, having a series of negative urine tests. We report on the use of hair testing to disclose sporadic cocaine consumption in seven subjects attending the Local Medical Commission to reobtain driver licence, with constant negative urinalysis. Even with one or two weekly negative urine screens along several months, all the subjects were positive using hair testing for cocaine and benzoylecgonine, above the internationally recommended limit of quantification: 0.5 ng/mg and 0.05 ng/mg for cocaine and benzoylecgonine, respectively (concentration range for cocaine: 0.51-2.23 ng/mg hair; concentration range for benzoylecgonine: 0.08-1.70 ng/mg hair). The obtained results support strongly the use of hair testing for cocaine in drug addicts and occasional abusers applying for regranting of driver licence in order to minimize social risk behaviours.

Cocaine is currently one of the most widespread abuse drugs in the world. Since hair cocaine concentrations are a reliable marker of exposition to the drug, an original liquid chromatographic method has been developed for the determination of cocaine in human hair. The chromatographic analysis was carried out on a Hydro-RP C18 column, using a mobile phase containing a phosphate buffer (pH 3.0)-acetonitrile-methanol (75:15:10, v/v/v). Native cocaine fluorescence was monitored at 315nm while exciting at 230nm. Mirtazapine was used as the internal standard. Sample pre-treatment was carried out by incubative extraction with 0.1M HCl followed by solid-phase extraction with C2 cartridges. Good linearity was obtained over a working range of 0.3-100.0ng/mg. Both extraction yield (>89%) and precision values (R.S.D.<6.2%) were highly satisfactory. The method was successfully applied to hair samples collected from cocaine users. Thus, the method is suitable for the long-term monitoring of cocaine use by means of hair testing.

Despite extensive evidence of fetal and neonatal risk, a large number of pregnant women are involved in excessive alcohol and drug abuse, such as with cocaine, methamphetamine, opioids, and cannabinoids.

Cocaine use during pregnancy is difficult to ascertain, and maternal reports are likely to be inaccurate. Presently, the dose-response characteristics between maternal cocaine use and fetal exposure and adverse effects are unknown. Clinically, some babies are harmed, whereas others are not adversely affected. Taking advantage of the fact that cocaine and its metabolite benzoylecgonine (BE) accumulate and can be detected months after exposure in maternal and neonatal hair, an analytical test for cocaine and BE was developed by the authors. The aim of this study was to describe the characteristics of maternal and neonatal hair cocaine as biomarkers of fetal exposure. Of nearly 10,000 cases, all mother-child pairs in whom at least one had cocaine and/or BE detected in hair were identified. The relationship between maternal and neonatal levels was studied. When available, these data were also compared with meconium levels of cocaine. Median cocaine concentration was 10-fold higher in hair of the mothers compared with the neonates (3.56 ng/mg vs 0.31 ng/mg of hair). Infants' cocaine in hair was positively correlated with maternal cocaine and BE in hair (r2 = 0.41 and r2 = 0.22, respectively, P < 0.001 for both correlations). Infants' BE was also correlated with maternal cocaine and BE concentrations in hair (r2 = 0.50 and r2 = 0.27, P < 0.001 for both correlations). Thirty-nine (40%) babies had negative cocaine and BE results despite their mothers being positive. Mothers whose infants were cocaine-positive had a median hair cocaine concentration of 7.34 ng/mg, significantly higher than those whose infants were negative (1.25 ng/mg). Maternal cocaine levels below 0.24 ng/mg may serve as a relative threshold for detectable fetal exposure during the third trimester of pregnancy. Fetal hair grows in the last trimester. Hence, a positive neonatal hair indicates maternal use after pregnancy became known, a strong indicator of maternal addiction. Transplacental exposure to cocaine of babies of addicted mothers is highly variable. The dose-response relationship of both cocaine and BE between maternal and neonatal hair suggests that the placenta protects some fetuses but not others. More research is needed to understand the mechanisms leading to placental defense against cocaine.

The National Laboratory Certification Program undertook an evaluation of the dynamics of external contamination of hair with cocaine (COC) while developing performance testing materials for Federal Drug-Free Workplace Programs. This characterization was necessary to develop performance materials that could evaluate the efficacy of hair testing industry's decontamination procedures. Hair locks (blonde to dark brown/black) from five different individuals were contaminated with cocaine HCl. Hair locks were then treated with a synthetic sweat solution and hygienic treatments to model real-life conditions. Hair locks were shampooed daily (Monday through Friday) for 10 weeks, and samples of the hair locks were analyzed for COC, benzoylecgonine (BE), cocaethylene (CE), and norcocaine (NCOC). Three commercial analytical laboratories analyzed samples under three protocols: no decontamination procedure, individual laboratory decontamination, or decontamination by an extended buffer procedure at RTI International. Results indicated substantial and persistent association of all four compounds with all hair types. Hair that was not decontaminated had significantly greater quantities of COC and BE than did hair that was decontaminated. The only hair samples below detection limits for all four compounds were those decontaminated 1 h after contamination. Additionally, BE/COC ratios increased significantly over the 10-week study (regardless of decontamination treatment). From 21 days postcontamination until the end of the study, the mean BE/COC ratio for all hair types exceeded 0.05, the proposed Federal Mandatory Guidelines requirement. The largest variability in results was observed for samples decontaminated by participant laboratories. This suggests that current laboratory decontamination strategies will increase variability of performance testing sample results. None of the decontamination strategies used in the study were effective at removing all contamination, and some of the contaminated hair in this study would have been reported as positive for cocaine use based on the proposed Federal Mandatory Guidelines.

Lack of disclosure of substance use is common in research and treatment settings and is frequently higher at follow-up than at baseline interviews. The aim of this study was to determine predictors of cocaine use disclosure at follow-up among 525 individuals who reported and tested positive for baseline use. Measurements included self-reported quantity and frequency of use, and hair analysis by radioimmune assay. Forty-two percent of individuals with biochemical evidence of continued cocaine use denied this use. In adjusted analyses, self-reported substance abuse treatment contact after enrollment was associated with lower disclosure (OR 0.63, 95% CI 0.43, 0.93). Other predictors were race, hair cocaine level, and opiates in hair. Failure to stop use after seeking treatment may result in reduced disclosure of continued use, possibly because of unwillingness to admit failure.

It has been proposed that issues of external contamination of hair can be resolved by the presence of metabolites. This is true for some drugs in some circumstances. However, even if some metabolites such as cocaethylene are sufficiently definitive to indicate certainty of use, others such as benzoylecgonine can occur as contaminants. In addition, for phencyclidine, only the parent compound is determined. Therefore, effective washing procedures are needed to rule out contamination as the source of the parent or metabolite. The protection provided by cutoffs is also dependent on washing to remove surface contamination, which can range from very little to greater than 20 times the amount in the hair. In cocaine-positive head hair samples from 67 subjects with cocaine-positive urine tests, contamination of positive hair samples ranged from 0.7 to 8009 ng/10 mg hair, demonstrating that analyses of such samples to determine use is meaningless without removal of contamination. Wash procedures have been a focus of this laboratory for many years. In this paper, the effectiveness of our wash procedure was further challenged by application to negative hair (blonde, auburn, brown, and black) contaminated by soaking for 1 h in 1000, 10,000, and 50,000 ng cocaine/mL water. The uptake of the cocaine was approximately linear with increasing concentrations of cocaine in the soaking solutions. By application of the wash criterion, all samples were clearly identified as contaminated (i.e., negative). The effects of hair porosity on uptake of cocaine were also studied with 10 hair samples of all colors. Permed and unpermed samples were soaked in 10,000 ng cocaine/mL for 1 hour. All hair responded to the perm with increased uptake, and all were decontaminated or identified as contaminated (i.e., negative for cocaine use). Porosity, not hair color, determined the rate of penetration of hair by cocaine in solution, and, likewise, washing characteristics were unrelated to hair color.

Because of its peculiar characteristics, hair analysis provides a way of obtaining information that cannot be acquired by other commonly used forensic medical analyses, such as blood or urine analysis. In the keratin matrix many xenobiotics are incorporated permanently, in contrast to the situation with blood or urine where they are generally only detectable for a few hours or days. Therefore hair analysis should be the method of choice in the clinical and forensic toxicology field when the assessment of repeated or chronic exposure to a drug is required, e.g. in the case of criminal responsibility, revocation/restoration of a driving licence or in workplace testing. Some factors that can affect the concentrations of drugs in hair, such as passive contamination, age, ethnicity and cosmetic treatment, must be considered. Analytical methodology is also very important: GC/MS/MS has proved to be a highly sensitive and specific technique for the detection of very low concentrations of such drugs in hair. In this study five cases of the application of hair analyses using this technique for the determination of abused drugs (opiates, cocaine, amphetamine, anabolic steroids) are described., (Copyright 2005 John Wiley & Sons, Ltd)

We report a case of a 6-year-old boy who had been living with his parents, both cocaine smokers, and who was urgently admitted to hospital for general distress. Upon examination, cocaine and cocaine metabolites were detected in hair and urine samples. These toxicological findings most likely indicate that the child had passively consumed the drug when living in a heavily contaminated environment.

Aim: Failure to disclose cocaine use can have a negative impact on medical care and research validity. This study was performed to identify predictors of cocaine non-disclosure among individuals who self-reported heroin use during a medical care encounter., Design: A prospective comparison of self-report of cocaine use among heroin users and hair analysis for cocaine., Setting: Four health-care clinics at an academic, inner-city hospital., Participants: Patients presenting for a health-care visit who were willing to self-report use of heroin and were not engaged in any form of drug treatment., Measurements: (1) Self-report using standardized instruments: the Drug Addiction Severity Test (DAST), the Addiction Severity Index (ASI) and quantity/frequency questions for heroin and cocaine use. (2) Biochemical evidence: analysis of hair by radioimmunoassay (RIA) for cocaine and opiate levels., Findings: Among 336 heroin users who tested positive for cocaine in hair, 34.2% did not report their recent cocaine use. The mean cocaine level for discordant individuals was significantly lower than for concordant individuals (109.6 ng/10 mg versus 470.57 ng/10 mg; P < 0.0001). Multivariate predictors of disclosure included opiate and cocaine levels in hair and the ASI drug severity subscore., Conclusions: Although self-report has been validated for treatment system patients, almost a third of the out-of-treatment heroin users in this medical clinic study failed to disclose concomitant cocaine use. The likelihood of non-disclosure was greatest for heavy users of heroin and light users of cocaine. Confirmation of self-report with biochemical analysis in the medical setting may be necessary to improve both clinical care and research validity.

In order to evaluate the effectiveness of a wash procedure using isopropanol followed by multiple extended phosphate buffer washes as compared with a methanol wash procedure previously reported, a contamination experiment was designed involving the soaking of human head hair in cocaine-contaminated aqueous solutions. Fourteen negative human head hair samples were soaked in a solution of cocaine HCl (1000 ng/mL) at room temperature for 1 h, then rinsed with distilled water and dried at room temperature. Using the extensive wash procedures (15-min isopropanol wash, followed by three 30-min phosphate buffer washes and then two 60-min washes), in no case would any of the samples be reported out as positive at a cut-off of 5 ng cocaine/ 10 mg hair. With the methanol procedure, 8 of the 14 methanol-washed samples exceeded a cut-off of 5 ng/10 mg hair. Extensive washing was shown to be far more effective for removal of external contamination than the methanol wash procedure reported. In all cases, the extensive aqueous wash protocol would allow the differentiation of ingestion versus external contamination, as defined by this soaking experiment. All samples underwent solid-phase extraction and derivatization followed by liquid chromatographic-tandem mass spectrometric analysis. Analysis was performed on a triple quadrupole API 2000 PerkinElmer Sciex mass spectrometer (MS) equipped with an atmospheric pressure ionization source via an ion spray interface. The MS operated in the positive Cl multiple reaction mode.

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.

Objective: To compare the sensitivity and specificity of maternal interview, maternal hair analysis, and meconium analysis in detecting perinatal exposure to cocaine, opiate, and cannabinoid., Design/methods: The use of cocaine, opiate, and cannabinoid during pregnancy was determined prospectively in 58 women by 3 methods: structured maternal interview, maternal hair analysis, and meconium analyses. The results of the 3 methods were compared with one another., Results: The maternal interview showed the lowest sensitivity in detecting cocaine and opiate exposures (65% and 67%, respectively), but it had the highest sensitivity in detecting cannabinoid exposure (58%). Both hair and meconium analyses had high sensitivity for detecting cocaine or opiate exposures. Hair analysis had a sensitivity of 100% for cocaine and 80% for opiate detection. However, it had a false-positive rate of 13% for cocaine and 20% for opiate, probably as a result of passive exposure. Meconium analysis had a sensitivity of 87% for cocaine and 77% for opiate detection, but unlike hair analysis, it had no false-positive test results for cocaine. Both hair and meconium analyses had low sensitivity in detecting cannabinoid exposure (21%-22.7%), most probably because of the sporadic use of cannabinoid., Conclusion: Meconium and hair analyses had the highest sensitivities for detecting perinatal use of cocaine and opiate, but not for cannabinoid. The principal drawback of hair analysis is its potential for false-positive test results associated with passive exposure to drugs. Maternal interview is a time-consuming test of low sensitivity. The high sensitivity of meconium analysis and the ease of collection make this test ideal for perinatal drug screening.

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.

Detection of current (past 30 days) drug use by analysis of hair was examined along with self-reports of current use in a 1994 treatment needs assessment survey; the sample was 179 homeless/transient adults in New York state. Results of radioimmunoassay of hair (RIAH) were used to evaluate the veracity of self-reports of current cocaine use. Only 26% of those persons whose hair tested positive for cocaine (n=115) admitted to having used cocaine in the past 30 days. Subjects eligible for treatment, as indicated by a DSM-III-R diagnosis of cocaine dependency, were nearly four times as likely to admit current cocaine use than those who were not dependent. These results are consistent with other studies of populations at high risk for substance use.

A total of 30 human head-hair samples were analyzed for cocaine (COC), cocaethylene (CE), benzoylecgonine (BE), methylecgonine (EME), and norcocaine (NCOC) using a sensitive positive ion chemical ionization gas chromatography-tandem mass spectrometry (GC-MS-MS) method. All 30 hair samples had been previously submitted to the laboratory and had confirmed positive for cocaine. Hair samples (20 mg each) were cut into small segments (2-5 mm) and incubated overnight at 45 degrees C in 0.1 N HCl after the addition of 50 microL of an internal standard mix of COC-d3 (1.0 ng/mg), BE-d3 (0.5 ng/mg), EME-d3 (0.25 ng/mg), and NCOC-d3 (0.25 ng/mg). The samples were then extracted with Clean Screen extraction columns from United Chemical Technologies, Inc. The final extract was evaporated to dryness and derivatized with 50 microL of 1,1,1,3,3,3-hexafluoro-2-propanol and 50 microL of trifluoroacetic anhydride at 90 degrees C for 15 min. The derivatized samples were allowed to cool to room temperature, evaporated to dryness, and then reconstituted in 50 microL of ethyl acetate. Parent set masses (unbolded ions) and product ions were m/z 304 and m/z 182 and 82 (COC), m/z 307 and m/z 185 and 85 (COC-d3), m/z 318 and m/z 196 and 82 (CE), m/z 440 and m/z 318 and 105 (BE), m/z 443 and m/z 321 and 105 (BE-d3), m/z 296 and m/z 182, and 82 (EME), m/z 299 and m/z 185 and 85 (EME-d3), m/z 403 and m/z 386 and 105 (NCOC), m/z 406 and m/z 389 and 105 (NCOC-d3). Quantitation was accomplished by calculating the area ratio of the higher mass product ion (underlined ions) of analyte to the respective internal standard based on multilevel calibrations from 0.01 to 10.0 ng/mg. The GC-MS-MS method had a limit of detection of 0.01 ng/mg and a limit of quantitation of 0.05 ng/mg for all five analytes. COC, BE, and EME were detected in all 30 samples, and CE and NCOC were found in 19 and 29 samples, respectively. The average relative percentages of each metabolite normalized to the cocaine concentrations were 12.8%, 15.4%, 1.8%, and 2.5% for BE, CE, EME, and NCOC, respectively.

Prenatal cocaine use is more accurately measured by maternal hair assay than by urine toxicology screening or self-report. To investigate the consequences of improved measurement, the authors ascertained cocaine use during pregnancy by maternal hair test, urine test, and self-report in a sample of 691 patients recruited from one New York City hospital in 1990-1992. Associations with intrauterine growth retardation, head circumference, and length of gestation were investigated. A positive hair test at delivery was not more strongly associated with birth weight (-38.1 g; 95% CI: -164, 88.3) or head circumference (-1.73 mm; 95% CI: -5.91, 2.44) than a positive urine test at delivery (-182 g (95% CI: -295, -69.8) and -6.11 mm (95% CI: -9.99, -2.24), respectively). Cocaine concentration in hair (which was higher if urine tests were positive) had a dose-response relationship with birth weight: a 27-g decrease (95% CI: -51.9, -1.04) with each log-unit increase in concentration. Birth weights were similar among infants of never users and infants of users who stopped using cocaine before delivery. Heavier use of cocaine, but not lighter use, was associated with intrauterine growth retardation, and exposure in late pregnancy was necessary to the association. Although maternal hair tests were instrumental in clarifying these relations, their clinical use is probably not warranted.

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.

Diagnosis of drug exposure is strongly supported by analysis of hair samples. In the province of Brescia, Italy, for regranting driving license to drug addicts or occasional abusers, a control programme was adopted including analysis of illicit drugs in two hair segments (0-3 and 3-6 cm) and in urine. From January 1998 to April 1999, upon request of the Local Medical Commission, 697 hair samples were tested in our laboratory. One hundred and eighty subjects resulted positive in hair for one or two of the controlled drug classes (73.3% for cocaine, 10% for opiates, 16.7% for both). Positive subjects were classified by residence, age, sex and license category. Seventy-two subjects were called back after 6-12 months and submitted to a second hair and urine analysis: in 34 cases the result of the first analysis was confirmed (19 negatives, 15 positives for one or both drug classes). Another 37 cases tested positive at the first control and negative at the second, suggesting the hypothesis that a strict control may have a significant deterrent function. The high percentage of negative results at the second control may be explained by the prevalence of cocaine users in the examined population. Our results allow us to conclude that the strict application of control rules lead to a decrease of social risk behaviours.

The present paper describes an integrated diagnostic strategy to check the physical fitness of subjects, formerly users of illicit drugs, to obtain a driving license, after having quit their addiction. According to the Italian law, applicants for a driving license with a history of drug abuse must give evidence to have quit this behaviour and to show no risk of relapse in the future. To prove this, at our institute, they undergo medical examination, hair analysis and a urinalysis program on eight seriate samples, collected over about 40 days. About 700 subjects per year are investigated with this strategy. The hair samples are screened for opiates (morphine), cocaine and ecstasy, the most abused illicit substances in our region, by using commercial radioimmunoassays adopting cut-off levels of 0.1 ng/mg. All positive samples and about 10% of negatives are confirmed by high-performance liquid chromatography. Further confirmation of results can be carried out by capillary electrophoresis (and/or GC/MS or MS/MS). In 1998, the prevalence of positives for morphine, cocaine and ecstasy was 4.8, 11.3 and 2.6%, respectively. In this year, for the first time, the percentage of hair samples positive for cocaine was greater than that for opiates. The results of this integrated diagnostic strategy are presented and discussed, with particular emphasis on the comparison between hair analysis on a single sample and seriate urinalyses (on eight samples).

Hair specimens were collected from 322 subjects and analyzed as part of an experimental study administering household surveys during 1997 to a high-risk community sample of adults from Chicago, Illinois. Toxicologic results were compared with survey responses about recent and lifetime drug use. About 35% of the sample tested positive for cocaine, and 4% tested positive for heroin. Sample prevalence estimates of cocaine use based on toxicologic results were nearly five times the survey-based estimates of past month use and nearly four times the survey-based estimates of past year use. With the hair test results as the standard, cocaine and heroin use were considerably underreported in the survey. Underreporting was more of a problem for cocaine than for heroin. Among those who tested positive, survey disclosure of cocaine use was associated with higher levels of cocaine detected in hair. In general, when recent drug use was reported, it was usually detected in hair. When a drug was detected in hair, use was usually not reported in the survey. When heroin was detected in hair, cocaine was almost always detected as well.

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 pigmentation is a critical factor in the interpretation of the concentration of certain compounds and their metabolites incorporated into hair. Melanin is responsible for the pigmentation. The color and the melanin content of human hair samples differs over a wide range. Once deposited into hair, drug may remain detectable for a period of months to years. However, if drug disposition into hair is influenced by those properties attributed to hair color, then certain persons may test positive more frequently than other persons. Removal of the melanin from hair digests prior to drug analysis may reduce the effect of melanin on the total drug concentration by excluding the drug bound to the pigment. In this study, the effect of melanin removal by centrifugation of hair digests on cocaine concentrations was investigated. Two sets of hair samples from five cocaine users were analyzed for cocaine and metabolites. A solution consisting of 10 mL of 0.5M Tris buffer (pH 6.4) to which is added 60 mg D,L-dithiothreitol, 200 mg SDS, and 200 U Proteinase K, was used to digest the hair. Two milliliters of this solution was added to 20 mg of hair and incubated at 37 degrees in a shaking water bath (90 oscillations/min) overnight. The samples were removed from the water bath and mixed. One set was centrifuged at 2000 rpm and divided into supernatant and melanin pellet. The other set was not centrifuged. Internal standards were added to all tubes. The samples were further extracted, derivatized, and analyzed by gas chromatography-mass spectrometry. A mean of 8.8% (standard deviation [SD] 7.0%) of the total cocaine concentration (supernatant and pellet) was left behind in the pellet. The same experiment was repeated except that the melanin pellet was redigested with 0.1 N HCl. After redigestion of the melanin pellet, the mean cocaine concentration in the pellet was 3.8% +/- 4.0% (mean +/- SD) of the total cocaine concentration in hair. These data demonstrate that removal of melanin from hair digests by centrifugation does not eliminate hair color bias when interpreting cocaine concentrations.

Intrauterine exposure to cocaine results in a variety of perinatal and long-term neurobehavioral sequlae. Maternal history and neonatal urinalysis miss most instances of exposure. After establishing the high sensitivity, specificity, and predictive value of neonatal hair testing for cocaine, the authors embarked on a study to evaluate the clinical use of the test. Between October 1991 and September 1997, they assessed the presence of cocaine in 509 hair samples; 422 were from neonates and were based on clinical suspicion of intrauterine exposure, although history and urine test results were negative. Thirty-two percent were positive, a rate fivefold higher than the incidence found by the authors in population-based studies. Neonates referred by children's aid workers had significantly higher percentages of positivity (60%). Because neonatal hair grows only during the last 4 months of pregnancy, positive neonatal hair test results reflect maternal addiction, and this warrants close follow-up of the baby after release because of the high rate of postnatal risks secondary to suboptimal parental care and because of the proven perinatal risks inflicted by the drug itself.

Background: There has been a steady increase in the number of newborns affected by maternal drug use. Cocaine and its metabolites cross the placenta and have been routinely measured in neonatal urine; however, due to the short half-life of the drug many exposed fetuses have negative urine tests. We have developed a neonatal hair test for measuring cocaine and its metabolites by radioimmunoassay. Since the validation of this test we prospectively evaluated its clinical utility by physicians, hospital nurseries and social welfare agencies who requested neonatal hair analysis to verify clinical suspicion of maternal cocaine use during pregnancy., Objective: The objective of the present research was to establish the sensitivity of the hair test in validating clinical suspicion of in utero exposure to cocaine in the presence of negative urine test., Hypothesis: We hypothesized that the use of the hair test in cases of clinical suspicion but negative urine test will yield a substantially higher rate of positivity than expected in the general population., Design: Between October 1991 and April 1995 we prospectively analyzed a total of 192 neonatal hair samples to confirm clinical suspicions of intrauterine exposure to cocaine. Of these, 10 did not have sufficient hair to analyze for cocaine metabolites., Results and Discussion: Fifty-five (30%) of the remaining 182 were positive for cocaine metabolite. This rate was 5.5-fold higher than the 5.5% found by us in a population-based research study in three nurseries in Toronto (p < 0.001), thus documenting the efficiency of this test in confirming clinical suspicions of fetal exposure to cocaine. Benzoylecgonine concentrations in this cohort were 2-fold higher than among positive cases in a previous population-based screening study (p = 0.0001) indicating that when clinical suspicions prompted physicians to test neonatal hair, they identify a subgroup of heavy cocaine users, who are probably at higher perinatal risks.