Identification and quantitation of cocaine and its metabolites, benzoylecgonine and ecgonine methyl ester, in hair of Bolivian coca chewers by gas chromatography/mass spectrometry.

Twenty hair samples obtained from Bolivian mine workers who chewed 3-8 g of coca leaves daily for several years were analyzed for cocaine and its main metabolites, benzoylecgonine (BZE) and ecgonine methyl ester (EME). A new method was developed for the detection and quantitation of cocaine and its metabolites, BZE and EME, from hair in a single procedure. The hair samples were washed, cut into 56 segments (2-cm length), pulverized, and incubated with phosphate buffer and the enzyme beta-glucuronidase-arylsulfatase. After solid phase extraction and derivatization with pentafluoropropionic anhydride/pentafluoropropanol, the drugs were identified and measured by gas chromatography/mass spectrometry (GC/MS) using deuterated cocaine, BZE, and EME as internal standards. The method is reproducible (cocaine, CV = 8%; BZE, CV = 14%) and the detection limit for cocaine and BZE was 0.1 ng/mg, for EME 1 ng/mg. In the different hair segments, cocaine was found to be present in concentrations between 1.4 to 50.6 ng/mg, benzoylecgonine from 0.4 to 17.6 ng/mg, and ecgonine methyl ester traces below the calibration curve of approximately 12.9 ng/mg. In 95% of the cases cocaine exceeded BZE and EME in concentration.     

Hair analysis for pharmaceutical drugs. I. Effective extraction and determination of phenobarbital, phenytoin and their major metabolites in rat and human hair

In order to establish an analytical method for the determination of phenobarbital (PB), phenytoin (PPH) and their hydroxylated metabolites in hair, animal model experiments were performed. Five male dark-agouti pigmented rats, aged 5 weeks, were intraperitoneally and orally administered PB or PPH independently at 25 mg/kg once a day for 5 successive days. The growing back hair was collected 15d after the first administration. Four typical extraction methods, using NH4OH-methanol-acetone, TFA-methanol-acetone, 1M sodium hydroxide and proteinase K, were evaluated using the rat hair samples containing PB or PPH. Methanol-acetone-NH4OH (10: 10: 1) was the best extraction method from all aspects, such as high extraction efficiency and low noise. The analytes in the extract were methylated in acetonitrile with 20% tetramethylammonium hydroxide and methyliodide at 70 degrees C for 10 min. After purification with Bond Elut Certify, the methylated products were analyzed by GC-MS. From rat hair, PB, p-hydroxy PB, PPH and p-hydroxy PPH were detected at average concentrations of 26.9, trace, 4.2 and 0.4 ng/mg with an intraperitoneal (i.p.) injection, and at 30.9, trace, 4.0 and 0.4 ng/mg with oral administration, respectively. There was little difference in hair concentrations between i.p. injection and oral administration. This method was applied to the head hair of two patients who orally took toxic amounts of PB and two volunteers who orally took 100 mg of PPH daily for 5 d. The hair concentrations of PB in the two patients were 16.2 and 14.7 ng/mg, and those of PPH in the two volunteers were 3.3 and 0.1 ng/mg.     

Solid-phase microextraction for cannabinoids analysis in hair and its possible application to other drugs

This paper describes the application of solid-phase microextraction (SPME) to cannabis testing in hair. Fifty milligrams of hair was washed with petroleum ether, hydrolyzed with NaOH, neutralized, deuterated internal standard was added and directly submitted to SPME. The SPME was analyzed by GC-MS. The limit of detection was 0.1 ng/mg for cannabinol (CBN) and delta9-tetrahydrocannabinol (THC) and 0.2 ng/mg for cannabidiol (CBD). THC was detected in a range spanning from 0.1 to 0.7 ng/mg. CBD concentrations ranged from 0.7 to 14.1 ng/mg, and CBN concentrations ranged from 0.4 to 0.7 ng/mg. The effectiveness of different decontamination procedures was also studied on passively contaminated hair. The proposed method is also suitable for the analysis of methadone in hair; cocaine and cocaethylene can be detected in hair with SPME extraction after enzymatic hydrolysis.     

Comparison of Cozart microplate ELISA and GC-MS detection of methadone and metabolites in human hair

The purpose of this study was to determine the performance characteristics of the Cozart Methadone Microplate ELISA assay for the detection of methadone and methadone metabolites in hair specimens. One hundred and ten hair specimens were collected from volunteers (n=46) with a history of drug use and from drug-related deaths (n=64). The hair samples (approximately 20 mg) were extracted by sonication in methanol followed by overnight extraction in methanol at 60 degrees C. The methanol extract was evaporated to dryness, reconstituted in ELISA negative calibrator, and then analyzed. For gas chromatography-mass spectrometry (GC-MS) analysis, deuterated internal standard mixture [methadone-d9 and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP)-d3] and 0.1M HCI were added to approximately 20 mg of specimen or spiked blank hair and sonicated for 1 h. The pH was adjusted to neutral, and methadone and its primary metabolite, EDDP, were analyzed by GC-MS following solid-phase extraction using Bond Elute Certify columns and pH 7.4 phosphate buffer (0.1M). Forty hair specimens were confirmed positive for methadone by GC-MS. Concentrations ranged from 0.10 to 8.3 ng/mg for methadone and 0.1 to 1.2 ng/mg for EDDP. The true positives, true negatives, false positives, and false negatives for different cutoffs with the ELISA were determined by comparison of the ELISA response (normalized to weight of hair extracted) to the GC-MS results with a cutoff of 0.1 ng/mg for both methadone and EDDP as the reference method. The optimum cutoff for the Cozart Methadone Microplate ELISA was determined to be between 200 and 300 pg methadone equivalents/mg hair using a 20 mg hair sample. The Cozart Methadone Microplate EIA for methadone and metabolites in hair using a cut-off of 200 pg/mg hair with a 20 mg hair sample had a sensitivity of 95 +/- 2% and a specificity of 100 +/- 3.5% (vs GC-MS) and an accuracy of 98.2 +/- 1.3%.     

Fully automated determination of cannabinoids in hair samples using headspace solid-phase microextraction and gas chromatography-mass spectrometry

This paper describes a fully automated procedure using alkaline hydrolysis and headspace solid-phase microextraction (HS-SPME) followed by on-fiber derivatization and gas chromatographic-mass spectrometric (GC-MS) detection of cannabinoids in human hair samples. Ten milligrams of hair was washed with deionized water, petroleum ether, and dichloromethane. After the addition of deuterated internal standards the sample was hydrolyzed with sodium hydroxide and directly submitted to HS-SPME. After absorption of analytes for an on-fiber derivatization procedure the fiber was directly placed into the headspace of a second vial containing N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) before GC-MS analysis. The limit of detection was 0.05 ng/mg for delta9-tetrahydrocannabinol (THC), 0.08 ng/mg for cannabidiol (CBD), and 0.14 ng/mg for cannabinol (CBN). Absolute recoveries were in the range between 0.3 and 7.5%. Linearity was proved over a range from 0.1 to 20 ng/mg with coefficients of correlation from 0.998 to 0.999. Validation of the whole procedure revealed excellent results. In comparison with conventional methods of hair analysis this automated HS-SPME-GC-MS procedure is substantially faster. It is easy to perform without use of solvents and with minimal sample quantities, but with the same degree of sensitivity and reproducibility. The applicability was demonstrated by the analysis of 25 hair samples from several forensic cases. The following concentration ranges were determined: THC 0.29-2.20 (mean 1.7) ng/mg, CBN 0.55-4.54 (mean 1.2) ng/mg, and CBD 0.53-18.36 (mean 1.3) ng/mg. 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid could not be detected with this method.     

Determination of buprenorphine and norbuprenorphine in urine and hair by gas chromatography-mass spectrometry.

Buprenorphine, which is used in France as a substitution drug for opioid addiction, is widely abused, and several fatal cases have been reported. In order to confirm a recent intoxication or to establish retrospectively chronic abuse, a simple and reliable gas chromatographic-mass spectrometric method was developed and validated for quantitation of buprenorphine and its active metabolite norbuprenorphine in urine and hair. Two milliliters of urine or 50 mg of pulverized hair was submitted to a pretreatment (enzymatic hydrolysis for urine and decontamination with dichloromethane followed by incubation in 0.1 M HCI for hair). Buprenorphine-d4 was chosen as the internal standard. Selective solid-phase extraction with Bond Elut Certify columns provided recoveries higher than 85% for urine and 43% for hair. By using a mixture of MSTFA/TMSIM/TMCS (100:2:5), buprenorphine and norbuprenorphine produced stable silylated derivatives. The detection was carried out with a quadrupole mass detector working in El selected ion monitoring mode. Ions at m/z 450 and 468 were chosen for the quantitation of buprenorphine and norbuprenorphine, respectively (m/z 454 was used for the internal standard). Limits of quantitation were 0.25 and 0.20 ng/mL, respectively, for buprenorphine and norbuprenorphine in urine and 0.005 ng/mg for the two compounds in hair. Calibration curves were linear from 0 to 50 ng/mL in urine and from 0 to 0.4 ng/mg in hair. Between-day and within-day precisions were less than 8.4% in hair and 6.1% in urine for both molecules in all cases. This method was applied to urine and hair samples collected from patients in a withdrawal treatment program and demonstrated its good applicability in routine analysis and its benefit for clinicians. This technique, which requires instruments already available to many toxicology laboratories, offers an attractive alternative to more sophisticated techniques.     

Reference values for hair cotinine as a biomarker of active and passive smoking in women of reproductive age, pregnant women, children, and neonates: systematic review and meta-analysis

Exposure to environmental tobacco smoke (ETS) is most often estimated using questionnaires, but they are unreliable. Biomarkers can provide valid information on ETS exposure, the preferred biomarker being cotinine. However, no reference range of hair cotinine exists to distinguish among active, passive, and unexposed nonsmokers. This study identifies cutoffs to validate cotinine as a marker for exposure to ETS. Data were obtained from six databases (four US, one Canada, one France). Active smoking and exposure to ETS were measured in the hair of women of reproductive age, pregnant women, their children, and neonates. Subjects were classified into active smokers, passively exposed to ETS, and unexposed nonsmokers. A total of 1746 cases were available for analysis. For active smokers, mean hair cotinine concentrations (95% confidence interval) were 2.3 to 3.1 ng/mg for nonpregnant women and 1.5 to 1.9 ng/mg for pregnant women. In the group of passive smokers, mean hair cotinine concentrations were 0.5 to 0.7 ng/mg for nonpregnant women, 0.04 to 0.09 ng/mg for pregnant women, 0.9 to 1.1 for children, and 1.2 to 1.7 for neonates. Among unexposed nonsmokers, mean hair cotinine was 0.2 to 0.4 ng/mg in nonpregnant women, 0.06 to 0.09 ng/mg in pregnant women, and 0.3 to 0.4 ng/mg in children. Cutoff values for hair cotinine were established to distinguish active smokers from passive or unexposed (0.8 ng/mg for nonpregnant women and 0.2 ng/mg for pregnant women). A cutoff value of 0.2 ng/mg was accurate in discriminating between exposed children and unexposed. These new values should facilitate clinical diagnosis of active and passive exposure to tobacco smoke. Such diagnosis is critical in pregnancy and in a large number of tobacco-induced medical conditions.     

Distribution of concentrations of cocaine and its metabolites in hair collected postmortem from cases with diverse causes/circumstances of death

The concentrations and ratios of cocaine, benzoylecgonine (BE), and ecgoninemethylester (EME) in 360 head hair segments and 34 pubic hair samples collected at coroner's postmortem examinations were reviewed. The cases included diverse histories and causes/circumstances of death. The hair was analyzed using a validated method published previously; hair was shampoo washed, solvent washed, followed by extraction using 0.1 M hydrochloric acid and SPE clean-up, and quantitative analysis by gas chromatography-mass spectrometry in selected ion monitoring mode. A statistical evaluation demonstrated that, in head hair, the respective lower, middle, and upper concentration (ng/mg) ranges were < 10 ng total-0.8, > 0.8-18.9, and > 18.9-384.7 cocaine; < 10 ng total-0.6, > 0.6-7.9, and > 7.9-142.2 BE; and < 10 ng total-0.3, > 0.3-0.9, and > 0.9-39.5 EME. In pubic hair, the concentrations (ng/mg) detected were 0.2-236.2 cocaine, < 10 ng total-74.0 BE, and < 10 ng total-3.2 EME. The BE/cocaine ratio range in head hair was 0.01-43.00 (mean 1.39, median 0.28), and in pubic hair it was 0.31-2.67 (mean 0.59, median 0.31). The EME/cocaine ratio in head hair ranged from < 0.01 to 0.46 (mean 0.04, median 0.02), and in pubic hair, it ranged from < 0.01 to 0.32 (mean 0.07, median 0.04). Results reported as < 10 ng total were above the limit of detection and below the limit of quantitation (LOQ) (LOQ = 0.2 ng/mg for 50 mg of hair).     

Opiate concentrations in hair from subjects in a controlled heroin-maintenance program and from opiate-associated fatalities

One month before (T-1) and 12 months after (T12) controlled intravenous administration of pharmaceutical heroin-HCl (10-1000 mg/d) in the context of a heroin-maintenance program, concentrations of opiates in head hair were determined (n = 46), using a validated gas chromatography-mass spectrometry method with limits of detection (LOD) between 0.02 and 0.04 ng/mg. In addition, a collective of opiate-associated fatalities was examined (n = 24). The obtained concentrations in the proximal segment (1 cm) of the patients were between 0.04 and 1.16 ng/mg (mean 0.13 ng/mg) for heroin (HER), between 0.02 and 32.41 ng/mg (mean 1.48 ng/mg) for 6-monoacetylmorphine (MAM) and between 0.03 and 11.79 ng/mg (mean 1.19 ng/mg) for morphine (MOR). With the exception of the analyte HER, there was no other statistically significant difference in the concentrations in comparison to the opiate fatalities [HER 1.55-5.20 ng/mg mean 3.38 ng/mg), MAM 0.04-30.01 ng/mg (mean 2.14 ng/mg), and MOR 0.03-11.87 ng/mg (mean 1.15 ng/mg) in the proximal segments]. After controlled HER administration, a correlation between the dose and the total opiate concentration in the hair was found (r = 0.66). These results disagree with the observations of authors who found only limited dose-concentration relationships after heroin abuse in hair. When considering a single analyte, the coefficient of correlation increased in correspondence to the respective plasma half-life (r = 0.42, r = 0.58, and r = 0.69 for HER, MAM, and MOR). The latter findings are in agreement with the report that states that this correlation is influenced by the plasma half-lifes of analytes. Codeine and acetylcodeine (AC) were detected in 50% and 43.5% (T-1) and 13% and 10.9% (T12) of the samples of the HER-maintenance program, as well as in 33.3% and 16.7% in opiate-associated fatalities, respectively. The lack of differences between obtained opiate concentrations in the hair of participants in a controlled heroin maintenance program and of opiate-associated fatalities does not support the hypothesis that an absence of tolerance can be regarded as a potential cause of death. In addition, the lack of AC, which was also observed in the majority of the deaths, questions its applicability as a characteristic marker of the consumption of illicit heroin.     

Hair analysis for drugs of abuse

The reliable analytical method for total morphine in hair was established by GC/MS-SIM. The calibration curve for morphine in hair showed linear over 0.5–100 ng/mg hair. Though the limit of detection was 0.1 ng/mg hair with an S/N >3 of the base ion(m/z 429) for morphine, the limit of confirmation by detection of three major ions was 0.5 ng/mg. The hydrolytic extraction of the morphine analogs in hair with 10% HCl for 1 h at 100° C gave quantitative recovery of morphine. The reproducibility of recovery of morphine spiked to the control hair was 2.9–7.3% in a concentration range between 2 and 50 ng/mg hair. The three monkeys were administered once a day with morphine at 10 mg/kg and heroin at 2.5 mg/kg, respectively, for 10 days and their back hair newly grown for 10 weeks was cut for analysis. The levels of total morphine in monkey hair intoxicated with morphine and heroin were 3.4 and 5.2 ng/mg, respectively. Taking their doses into account, it is concluded that the morphine level in hair from monkeys administered with heroin was 6 times higher than that with morphine. In hair from monkeys and humans intoxicated with heroin, 6-acetylmorphine was detected at the level of 0.7–7.2 ng/mg as a major component in hair together with morphine and no heroin. Drug concentrations of sectional hair shaft cut 2 cm each from the root side were compared with the self-reported drug histories of three cases. The results of sectional analysis of heroin abuser's hair suggested that the relationship between the distribution of morphine along hair shaft and the drug use history showed a good correlation, though the accumulation of heroin metabolites in body could result from chronic use of heroin.     

Norcocaine and cocaethylene distribution patterns in hair samples from light,moderate, and heavy cocaine users

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.     

Accumulation of β-agonists clenbuterol and salbutamol in black and white mouse hair

Hair has been shown to be an excellent site for the accumulation of different drugs including β-agonists, and therefore, it would be an appropriate matrix for surveillance for the presence of drug residues. The aim of this study was to determine concentrations and to compare accumulation of two different β-agonists in black and white mice hair by use of ELISA as a screening quantitative method. The study included 200 8-week-old white and black mice. One group of black mice and one group of white mice were treated with clenbuterol in a dose of 2.5 mg/kg body mass per os for 28 days. Other animals were treated in the same way with salbutamol. The highest (±SD) clenbuterol concentration of 631.4 ± 23.5 ng/g in black hair and 228.5 ± 156.2 ng/g in white hair was determined on day 1 of treatment withdrawal. Study results revealed the black-to-white hair ratio of clenbuterol accumulation to be 1:2-1:4 and of salbutamol accumulation 1:1.4. The mean (±SD) salbutamol concentrations determined on day 1 of treatment withdrawal was 23.9 ± 0.9 ng/g and 16.4 ± 1.1 ng/g in black and white hair samples, respectively. The study demonstrated that residues could be determined in hair samples even after a 30-day withdrawal period.     

Simultaneous detection and quantitation of morphine, 6-acetylmorphine, and cocaine in toenails: comparison with hair analysis

This study describes the results of the simultaneous detection and quantitation of morphine, 6-acetylmorphine, and cocaine in toenail and hair samples obtained from 18 forensic autopsies of drug abusers who had died in various manners. After external decontamination, each specimen was submitted to hot acid hydrolysis (1 mL of HCl 37%) in the presence of internal standards, followed by liquid-liquid and solid-phase extraction techniques. The extracts were then derivatized with propionic anhydride and analyzed by gas chromatography-mass spectrometry, operating in the selected ion monitoring mode. The limit of quantitation for all analytes was 0.5 ng on column. Results showed that both cocaine and morphine are more concentrated in toenails than in hair. Mean concentrations were 0.99 ng/mg (toenails) versus 0.48 ng/mg (hair) for cocaine and 1.27 ng/mg (toenails) versus 0.79 ng/mg (hair) for morphine. Distribution of 6-acetylmorphine showed no significant variations between the two (mean concentrations 0.46 ng/mg vs. 0.50 ng/mg in hair).     

LC-MS-MS analysis of the neuroleptics clozapine,flupentixol, haloperidol,penfluridol, thioridazine,and zuclopenthixol in hair obtained from psychiatric patients

Hair samples of psychiatric patients were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS-MS) for the neuroleptics clozapine, flupentixol, haloperidol, penfluridol, thioridazine, and zuclopenthixol. In the study, these neuroleptics were administered to the patients regularly for a minimum of six months. Sample preparation was performed by washing, powdering with a ball mill, extraction of drugs from hair by ultrasonication with methanol, cleanup by solid-phase extraction and subsequent LC-MS-MS analysis using multiple reaction monitoring (MRM). Calibration was performed for all drugs in the range of 0.05 to 10 ng/mg using spiked hair powder and doxepin-d3 as internal standard. Twenty to 50 mg of hair powder was used and the detection limits of LC-MS-MS were below 0.05 ng/mg for all drugs tested. Therapeutic dosage, number of subjects, hair color, and detected amounts of drugs were as follows: clozapine (150400 mg/day; n = 3, light brown, medium brown, black; 0.47-0.92 ng/mg), haloperidol (150 mg/3 weeks; n = 1, black/gray; 12.2 ng/mg), penfluridol (20-30 mg/week; n = 2, medium brown, black; 0.08 ng/mg; not detected in one case), thioridazine (100-400 mg/day; n = 4, light brown, medium brown, black; 0.33-9.91 ng/mg, not detected in one case). Besides the active drugs also the desmethyl-metabolites of clozapine and thioridazine were detected by LC-MS-MS. However, flupentixol (5 mg/day; light brown hair) and zuclopenthixol (350 mg/3 weeks; light brown hair) were not detected by these methods in one case each, although the drugs were administered regularly to these patients. The comparison of dosage and hair color in two cases with thioridazine and penfluridol suggests that other interindividual factors may have an influence on drug concentration in hair.     

Compatibility of aminophylline and verapamil in intravenous admixtures

The chemical and visual compatibility of aminophylline and verapamil hydrochloride in intravenous admixtures was evaluated. Verapamil hydrochloride injection was added to a solution of aminophylline 1.0 mg/mL in 5% dextrose injection (D5W) to yield final verapamil hydrochloride concentrations of 0.1 and 0.4 mg/mL. Each solution type was prepared in triplicate. An aliquot from each of these solutions was assayed in duplicate for theophylline and verapamil by high-performance liquid chromatography at 0, 4, 8, 12, and 24 hours after mixing. All aliquots were filtered with a 0.22-micron filter immediately before assay. At each time interval, samples were assessed for pH and inspected visually and microscopically for evidence of incompatibility. Theophylline concentrations showed less than 10% change over 24 hours in the two-drug admixtures. Less than 1% of the original verapamil concentrations remained immediately after mixing with aminophylline injection in D5W. Turbidity was readily apparent in the admixture containing verapamil hydrochloride 0.4 mg/mL; however, microscopic evaluation revealed precipitate in both solutions. Solution pH was determined to be a primary cause of precipitation. The mean pH values for the verapamil hydrochloride 0.1 and 0.4 mg/mL control solutions were 4.09 and 4.36, respectively. The mean pH of the aminophylline 1.0 mg/mL control solution was 8.35. The mean pH of the aminophylline-verapamil admixtures at verapamil hydrochloride concentrations of 0.1 and 0.4 mg/mL was 8.14 and 8.06, respectively. Verapamil hydrochloride injection in final concentrations of 0.1 and 0.4 mg/mL is incompatible with aminophylline 1.0 mg/mL in D5W.     

Interindividual dose/concentration relationship for methadone in hair

Hair samples were collected from 60 patients receiving long-term methadone maintenance: 50 were taking the drug orally and 10 were receiving the drug by intravenous injection. The amount of methadone present in the hair samples was measured using methanolic extraction, derivatization of the extracts with MTBSTFA, followed by electron impact gas chromatography-mass spectrometry operating in selected ion monitoring mode. The limit of quantitation for the assay was 0.4 ng/mg hair. The dose/concentration relationship for methadone in hair was investigated. No interindividual correlation between prescribed dose and concentration of methadone in hair was observed.     

Determination of endogenous levels of GHB in human hair. Are there possibilities for the identification of GHB administration through hair analysis in cases of drug-facilitated sexual assault?

We have developed a GC-MS-MS assay for GHB in human hair. Five milligrams of washed hair were hydrolyzed by 1M or 0.01M NaOH before a liquid-liquid extraction with ethyl acetate under acidic conditions. GHB-d(6) was used as the internal standard. TMS derivatives were formed before injection. TBDMS derivatives were used in cases of strong chromatographic interferences or in a confirmatory procedure. Analysis of basal levels of GHB in 61 drug-free donors gave the following results: the mean measured concentration for blond hair was 0.60 ng/mg (n = 12), SD = 0.19 ng/mg, and extreme figures were in the range 0.35-0.95 ng/mg. For brown hair, the mean measured concentration was 0.90 ng/mg (n = 30), SD = 0.42 ng/mg, and extreme figures 0.41-1.86 ng/mg. For black hair, the mean measured concentration was 0.90 ng/mg (n = 19), SD = 0.37 ng/mg, and extreme figures 0.32-1.54 ng/mg, showing no significant differences depending on hair color. Analysis of basal levels of GHB of 12 or more specimens in segmented hair showed a mean concentration of 1.22 ng/mg (0.31-8.4 ng/mg) and a relative standard deviation for each individual ranging from 6.75% to 37.98%. GHB was administered to a healthy 53-year-old white male (light brown hair) at oral dosages of 30, 45, and 60 mg/kg. Beard hair was collected just before administration and 24 h after (and each day for one week for the last dose), and a 7.5-cm scalp hair lock was collected 7 days after the last dose. A rise in GHB concentration was observed in beard hair for the 45 and 60 mg/kg dosages with a maximum at 24 h, whereas no change was observed for the 30 mg/kg dosage. Scalp hair was segmented into 3-mm long segments. The three proximal last segments showed significantly (0.0005 < p < 0.005) different concentrations of GHB (1.22, 1.27, and 1.66 ng/mg, respectively) when compared with the basal physiological level of GHB in this same person (mean = 0.62 ng/mg, SD = 0.15 ng/mg). A case of daily GHB abuse during bodybuilding allowed us to determine a concentration of GHB of 14 ng/mg, in a 2-cm long segment (black hair). A case of rape under the influence of GHB was documented through hair analysis (black hair) and positive analysis of the glass she used. Sampled 7 days after the sexual assault, the three last 3-mm long proximal segments tested for GHB exhibited concentrations of 3.1-5.3 and 4.3 ng/mg, respectively, whereas the mean physiological level determined in this woman was 0.71 ng/mg, SD = 0.17 ng/mg. The authors advise a two-step hair sampling as evidence of GHB consumption: the first sample at the time of exposure to show the contamination by sweat of the proximal segment in case of recent administration with a significant rise of hair level at the root, and the second after at least 3 or 4 weeks to avoid this contamination and determine the levels incorporated in the hair matrix before, during, and after the exposure.     

Hair nicotine/cotinine concentrations as a method of monitoring exposure to tobacco smoke among infants and adults

In this pilot study, we examined the validity and usefulness of hair nicotine-cotinine evaluation as a biomarker of monitoring exposure to tobacco. Head hair samples were collected from 22 infants (<2 years of age) and 44 adults with different exposures to tobacco (through either active or passive smoking) and analyzed by liquid chromatography-mass spectrometry (LC-MS) for nicotine and cotinine. Hair samples were divided into three groups, infants, passive smoker adults and active smoker adults, and into eight subgroups according to the degree of exposure. The limit of quantification (LOQ) was 0.1 ng/mg for nicotine and 0.05 ng/mg for cotinine. Mean recovery was 69.15% for nicotine and 72.08% for cotinine. The within- and between-day precision for cotinine and nicotine was calculated at different concentrations. Moreover, hair nicotine and cotinine concentrations were highly correlated among adult active smokers (R (2) = 0.710, p < 0.001), among adult nonsmokers exposed to secondhand smoke (SHS; R (2) = 0.729, p < 0.001) and among infants (R (2) = 0.538, p = 0.01). Among the infants exposed to SHS from both parents the noted correlations were even stronger (R (2) = 0.835, p = 0.02). The above results identify the use of hair samples as an effective method for assessing exposure to tobacco, with a high association between nicotine and cotinine especially among infants heavily exposed to SHS.     

Amphetamine and N-acetylamphetamine incorporation into hair: an investigation of the potential role of drug basicity in hair color bias

To elucidate the role of drug basicity in the preferential incorporation of certain drugs into dark hair rather than light hair, Long-Evans rats were dosed with amphetamine or its non-basic analogue N-acetylamphetamine (N-AcAp) and their hair evaluated for drug content. Rats were shaved prior to dosing. On the 14th day after dosing, hair from the same area that was shaved prior to dosing was shaved and collected. After the addition of amphetamine-d3 or N-AcAp-d3 as an internal standard, hair samples (20 mg) were digested in 1M NaOH at 37 degrees C. Digested solutions were then extracted with n-butyl chloride/chloroform (4:1, v/v). After drying and reconstituting, samples were injected onto a ThermoQuest TSQ liquid chromatography-tandem mass spectrometry instrument for analysis. Black hair from rats dosed with amphetamine (n = 8) was found to contain 6.44 +/- 1.31 (SD) ng amphetamine/mg hair. White hair from the same rats contained 2.04 +/- 0.58 ng amphetamine/mg hair. In contrast, no difference in N-AcAp content was found between black hair (0.87 +/- 0.08 ng N-AcAp/mg hair) and white hair (0.83 +/- 0.15 ng N-AcAp/mg hair) from rats dosed with N-AcAp (n = 8).