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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.)

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.)

The Scott test, widely used as the field test for cocaine, is performed in three steps. If a sample contains cocaine, blue precipitates appear in step 1, the precipitates are dissolved and the solution turns pink in step 2, and the lower layer turns blue in step 3. However, some pyrrolidine-type cathinones produce cocaine-like results when tested, necessitating modification of the test procedure. Filtration of the second-step mixture weakened the blue color in step 3; however, the blue color did not completely disappear. Adding the Chen-Kao reagent to the test procedure enhanced the differentiation: when the reagent was added to cocaine, the solution was initially turbid, but then became clear over time; its addition to cathinones resulted in turquoise or light sky-blue precipitation. These results indicated that the Chen-Kao test was useful for exclusion of cathinones. A combination of the modified Scott test and the Chen-Kao test was successfully applied to the forensic samples containing cocaine or pyrrolidine-type cathinones. In conclusion, a combination of these tests will be the useful field-test procedure for cocaine., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

The objectives of present work are twofold. First, we want to verify that hygrine and cuscohygrine are good markers to distinguish between chewing coca leaves and cocaine abuse. Secondly, we try to develop a quick and easy qualitative method to determine the two mentioned markers. We analyzed two kinds of urine samples: the first group consisted of twenty-four (24) subjects: urine samples were obtained from various types of workers (e.g. doctors, chemists, nurses, technicians, painters, contractors, employees and some retired persons) who admitted chewing coca leaves. Frequency of the habit of chewing coca leaves was variable. They practiced "coqueo" between two (2) and forty-four (44) years. Sixteen (16) of them used alkaline substances to enhance the extraction of cocaine from the leaves The second group of urine samples consisted on thirty-eight (38) cocaine abusers, from forensic cases from Spain and Argentina. A GC/MS qualitative method, performed after liquid-liquid extraction, was developed and validated (the parameters studied were selectivity/specificity, LOD and stability), and then applied to the urine samples. Hygrine and cuscohygrine are good markers to distinguish between chewing coca leaves and cocaine abuse, and the qualitative method presented can be used successfully in workplace drug testing and forensic cases., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

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.)

Cocaine abuse is widespread all over the world, and is performed generally by sniffing, injecting or smoking cocaine or crack. The distinction between the recreational use of cocaine from the practice of the so called "coqueo" is still an issue in those countries where this habit is diffused and where it is not considered an addiction, by this reason is necessary to develop a method for to distinguish the coca chewers and cocaine abusers. The use of an unique marker to distinguish between cocaine abuse and chewing of coca leaves is of fundamental importance in those countries where this habit is diffused. Certain alkaloids of the leaves of Erythroxylum coca are lost during the process of extraction/purification of cocaine and it is not possible to find them neither in seizures of chlorhidrate of cocaine nor urine samples of cocaine abusers. These markers are the hygrine and cuscohygrine that are present in the leaves of E. coca. A fast GC/MS method involving a liquid:liquid extraction procedure with tertbutylmethylether (TBME) is proposed for the determination of some alkaloids in cocaine leaves, cocaine seizures and biological samples. All specimens were alkalinized to pH 9 with a carbonate/bicarbonate buffer and then extracted with TBME. The analysis was carry out by GC/MS with electron impact at 70 eV and in full scan mode. The results demonstrate that hygrine and cuscohygrine are not found neither in the urine of cocaine abusers nor in cocaine seizures. For this reason this compounds could be considered as markers of coca chewing. This developed method permits to distinguish coca chewing from cocaine abuse in workplace drug testing through the analysis of urine samples., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

This study assesses the interpretive value of cocaine, benzoylecgonine (BZE) and cocaethylene (COET) in skeletal muscle (rectus femoris) in cocaine-using decedents. The distribution of these analytes in cardiac muscle (CM), vitreous humour (VH), femoral blood (FB) and cardiac blood (CB) is also reported. In rectus femoris muscle, the spatial distribution of the analytes was examined across the whole rectus femoris muscle collected from seven fatalities in which cocaine was detected. In six of these cases, death was attributed to trauma and in one case the cause of death was undetermined but suspected to be drug related. In two additional cases analytes were detected in the blood and/or VH but not in the muscle. The muscle was sectioned into 12-15 approximately equal segments, each of which was analysed after homogenisation. Tissue and bio-fluid samples were extracted by solid phase extraction with confirmation and quantification by GC-ion trap-MS/MS. No significant variation was observed in the concentration of any analyte throughout the muscle in the 7 cases analysed. The results reported here are in contrast to a previous study in which great variation in the concentration of some basic drugs (mainly tricyclic antidepressants and benzodiazepines) was observed throughout the thigh muscle bulk (Williams and Pounder, 1997). Analyte concentrations in skeletal muscle (SM) correlated well with those in FB (p<0.01). In general, the concentration of cocaine and COET followed the order VH > CM > SM > FB ≥ CB. Cocaine concentrations measured in VH were significantly higher than in blood and muscle. Inter-matrix variations in the concentrations of BZE and COET were less marked. The concentration of BZE exceeded that of cocaine in all matrices and in all cases except one where the time between death and drug intake was suspected to be short. In this case, the cocaine to BZE ratio measured in SM (2.66), CM (2.91) and VH (2.19) was higher than that measured in FB (0.97). Given that the concentrations of cocaine and its metabolites were uniformly distributed throughout the muscle and considering the good correlation observed between muscle and blood, muscle could be of interpretive value in cocaine related deaths. Further, since cocaine is known to have greater post-mortem stability in muscle than blood, concentrations measured in muscle may reflect more closely those at the time of death and might be of particular value in cases with an extended period between death and tissue sampling., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

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.)

Due to an in vitro decomposition of cocaine (COC), usually an analytical detection in unstabilized blood taking systems is impossible and for this reason the main metabolite benzoylecgonine (BZE) is determined. In a few regions in Germany the local authorities use systems containing sodium fluoride for taking a blood sample. Caused by inhibition of esterases in the taken sample COC is still detectable in blood samples. Cases of driving under the influence (DUI) with positive findings for COC and/or BZE were evaluated and substance concentrations in plasma were correlated with documented deficiencies in the psycho-physical performance. In 51.5% of all cases positive for cocaine-like substances besides BZE a positive result was also given for COC. If both substances were found (mean COC concentration 0.836 mg/L) the concentration of BZE was significantly higher (mean 0.669 mg/L) compared to cases with a single detection of BE (mean 0.209 mg/L) (p=0.001). In 72 cases without any detection of further drugs cocaine users seemed rather excited and stimulated towards intervening police officers, in particular when COC was present in the blood (17.8%). Also in the medical investigation reports a rather stimulative effect (25% vs. 3.6% sedated) was to be registered. Whereas with a sole determination of BZE, a stimulated (19%) as well as a sedated impression (14.9%) was described. Definite concentration-effect relations could not be recognized. Indeed, more peculiarities were to be registered with the simultaneous detection of COC than with a sole BZE determination. The determination of COC and the differences in the BZE concentration can be explained by the fact that the simultaneous detection of both substances is indicative for of a consumption shortly before the blood sampling. A sole detection of BZE is more likely indicative for a consumption already some time ago. Therefore, in the first case one would rather suggest an acute intoxication phase. A determination of BZE without COC is more likely indicative for a transition to the drug-induced exhaustion phase which is also to be expected after the consumption of COC. The absence of COC can be seen within the scope of a validity check as an indication of a possible exhaustion reaction. A use of fluoride stabilized blood sampling systems is advised. This makes it easier to investigate the state of intoxication or to appraise the temporal connection between COC consumption and incident or blood sampling., ((c) 2010 Elsevier Ireland Ltd. 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 and its major metabolite benzoylecgonine (BZE) were determined in blood samples from people arrested in Sweden for driving under the influence of drugs (DUID) over a 5-year period (2000-2004). Venous blood or urine if available, was subjected to a broad toxicological screening analysis for cannabis, cocaine metabolite, amphetamines, opiates and the major benzodiazepines. Verification and quantitative analysis of cocaine and BZE in blood was done by gas chromatography-mass spectrometry (GC-MS) at limits of quantitation (LOQ) of 0.02mg/L for both substances. Over the study period 26,567 blood samples were analyzed and cocaine and/or BZE were verified in 795 cases (3%). The motorists using cocaine were predominantly men (>96%) with an average age of 28.3+/-7.1 years (+/-standard deviation, S.D.). The concentration of cocaine was below LOQ in 574 cases although BZE was determined at mean, median and highest concentrations of 0.19mg/L, 0.12mg/L and 1.3mg/L, respectively. In 221 cases, cocaine and BZE were together in the blood samples at mean and (median) concentrations of 0.076mg/L (0.05mg/L) and 0.859mg/L (0.70mg/L), respectively. The concentrations of BZE were always higher than the parent drug; mean BZE/cocaine ratio 14.2 (median 10.9) range 1-55. Cocaine and BZE were the only psychoactive substances reported in N=61 cases at mean (median) and highest concentrations of 0.095 (0.07) and 0.5mg/L for cocaine and 1.01 (0.70) and 3.1mg/L for BZE. Typical signs of drug influence noted by the arresting police officers included bloodshot and glossy eyes, agitation, difficulty in sitting still and incoherent speech.

In a study of subjects in drug rehabilitation programs, cocaine and cocaine metabolite levels were determined in the hair of 75 subjects who had produced cocaine-positive urine results. The hair was analyzed after being washed with the 3.75 h wash procedure developed by this laboratory. In addition, results of testing 73 non-users are presented, as well as levels of cocaine, benzoylecgonine (BE), cocaethylene, and norcocaine from workplace population samples. The data support a recommendation of reporting as positive a sample with cocaine of 500 pg/mg hair and either a 5% ratio of benzoylecgonine (BE) to cocaine in samples, or the presence of cocaethylene at 50 pg/mg hair, or norcocaine at 50 pg/mg hair for samples < or =2000 pg cocaine/mg hair. For samples with cocaine present at >2000 pg/mg hair, the data indicate that a ratio of 5% BE may be an overly conservative approach. In appropriately washed hair samples, cocaine users can produce hair levels of <5% BE and thus a minimum BE cutoff in lieu of a ratio could be considered.

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.

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.

In a series of licit and illicit drug-related deaths, qualitative and quantitative analyses on extracts of adipose tissue and skin were performed by GC/MS. In all cases, the adipose tissue was found to contain drugs at concentrations lower than, approximately equal to, or even greater than the concentrations of the same analytes found in the blood, which may reflect a consequence of long-term chronic exposure, or acute intoxication, or some combination of both. Approximately one cubic inch of skin with adipose tissue was removed from the mid to lower abdominal region adjacent to the midline incision during autopsy. The drugs were recovered from the specimens following incubation and alkaline, acidic, and alkaline chloroform back extraction of one to three grams of tissue. Deuterated analogs of the analytes were added to the matrix at the beginning of the incubation period. Cocaine and free morphine (from heroin) were readily identified in several cases. The presence of these illicit drugs in adipose tissue raises significant forensic questions, especially the use of 'sweat patches' to monitor recent cocaine or heroin use in chronic drug users.

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).