Detection of antidepressant and antipsychotic drugs in human hair

Chromatographic Methods for the Analysis of the Antipsychotic Drug Clozapine and Its Major Metabolites: A Review

Clozapine (CLZ), a second-generation antipsychotic, can effectively reduce schizophrenia, bipolar disorder and major depression symptoms. This review provides an overview of all reported chromatographic methods (62 references) for the quantification of CLZ and its two main metabolites, norclozapine and clozapine N-oxide in pharmaceutical formulations, biological matrices and environmental samples.

Determination of amphetamines, ketamine and their metabolites in hair with high-speed grinding and solid-phase microextraction followed by LC-MS

A novel hair sample pre-treatment method based on high-speed grinding and solid-phase microextraction (SPME) had been applied for the determination of amphetamines, ketamine and their metabolites in hair samples by liquid chromatography-mass spectrometry (LC-MS). A 20 mg sample of hair was ground with 2 mL of saturated sodium carbonate solution using a high-efficiency hair grinder with 70 Hz oscillation for 2 min at 4 °C. After centrifuging, 1.5 mL of the supernatant was transferred and treated with SPME by direct immersion (DI-SPME). The target analytes extracted by fibre were desorbed and analysed using LC-MS. Under the optimum conditions, a recovery of 90.2%–95.8% was obtained for all analytes. The analytical method was linear for all analytes in the range from 0.2 to 10 ng/mg with the correlation coefficient ranging from 0.9985 to 0.9993. The detection limits for all analytes were estimated to be 0.067 ng/mg. The accuracy (mean relative error) was within ±6.9% and the precision (relative standard error) was less than 6.8%. The combination of high-speed grinding of hair and SPME had the advantages of being easy to perform, environment-friendly and high in detection sensitivity. The proposed method offered an alternative analytical approach for the sensitive detection of drugs in hair samples for forensic purposes.

Key Points

The SPME was involved for the determination of drugs in hair with LC-MS.

The hair high-speed grinding combined with SPME was firstly developed.

Good linearity, sensitivity, recovery and precision were achieved.

Current status of hair analysis in forensic toxicology in China

Hair analysis has been mainly used to document drug use history in abusers, drug-facilitated crime cases, doping control analysis and postmortem toxicology in the fields of forensic toxicology, clinical toxicology, and doping control. Hair analysis has also gained more attention in the last 30 years in China. Relevant technology has been promoted as more research has appeared concerning hair analysis, and consensus has been sought among forensic toxicologists regarding aspects such as hair decontamination treatment, detection of abused substances in hair, segmental hair analysis and interpretation of analytical results. However, there are still some limitations in the estimation of drug intake time and frequency by segmental hair analysis due to the different growth cycles evident within a bundle of hairs, the drug incorporation mechanism and sampling errors. Microsampling and imaging mass spectrometry (IMS) technology based on a single hair may be a good choice to estimate drug intake time more accurately. Analysis of hair root samples may also be used to document acute poisoning in postmortem toxicology, and the analysis of the hair shaft can document long-term use of drugs depending on the length of the hair being evaluated.

Determination of antidepressants and benzodiazepines in paired hair and nail samples

Hair and nails are keratinized matrices that can be used in Toxicology as matrices for the long-term detection of substances. Whereas hair is an established matrix with decades of use in this field, nails have been less studied, especially including a comparison to hair samples. Specifically in the case of antidepressant and benzodiazepine drugs, very few publications analyzing these drugs in nail samples exist as of yet. For this reason, in the present study a method for the detection of 12 antidepressant and benzodiazepine drugs in hair and nail samples was developed. Samples were decontaminated with 3 washes of dichloromethane, and 25 or 30 mg of hair and nails, respectively, were pulverized. Then, the samples were incubated with 1.5 mL water:ACN (50:50, v/v) with horizontal agitation for 90 min. The supernatant was evaporated and reconstituted in 200 µL of methanol and 2 mL of 2% FA in water, submitted to solid phase extraction (SPE) using Oasis MCX cartridges and analyzed by LC-MS/MS. The method was satisfactorily validated in nail and hair samples for the following parameters: linearity, LOD (0.005-0.02 ng/mg), LOQ (0.01-0.02 ng/mg), selectivity, carryover, accuracy, imprecision, matrix effect, extraction efficiency, process efficiency and autosampler stability. Matched fingernail, toenail and hair samples were obtained from 21 patients under treatment with any of the studied drugs and analyzed with the developed method. The most frequently detected drugs were venlafaxine (n = 11), trazodone (n = 6), zolpidem (n = 5), alprazolam (n = 5) and nordiazepam (n = 5). Concentrations in hair, fingernails and toenails, respectively, were 44.31 ng/mg, 8.05-43.35 ng/mg and 7.02-22.69 ng/mg for venlafaxine; 5.40-19.08 ng/mg, 0.13-1.00 ng/mg and 0.42-1.04 ng/mg for trazodone; 13.86 ng/mg, 5.19 ng/mg and 9.11 ng/mg for fluoxetine; 7.42 ng/mg, 1.85 ng/mg and 0.03-2.81 ng/mg for sertraline; 0.40-1.42 ng/mg, 0.12 ng/mg and 0.16 ng/mg for zolpidem; and 0.02-0.11 ng/mg, 0.07-1.07 ng/mg and 0.05 ng/mg for alprazolam for the patients under active treatment. Hair concentrations were higher than nail concentrations for most drugs in patients under active treatment, with the exception of diazepam (n = 1; 0.12 ng/mg in hair and 0.41 ng/mg in fingernails). Fingernail concentrations were lower than toenail concentrations in patients under active treatment in most compared cases. Comparison of fingernails and toenails of a patient with antifungal treatment did not show an observable effect in concentrations.

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

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

Segmental Analysis of Chlorprothixene and Desmethylchlorprothixene in Postmortem Hair

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

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

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

Post-mortem quetiapine concentrations in hair segments of psychiatric patients - Correlation between hair concentration, dose and concentration in blood

Drug analysis in hair is useful when seeking to establish drug intake over a period of months to years. Segmental hair analysis can also document whether psychiatric patients are receiving a stable intake of antipsychotics. This study describes segmental analysis of the antipsychotic drug quetiapine in post-mortem hair samples from long-term quetiapine users by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The aim was to obtain more knowledge on quetiapine concentrations in hair and to relate the concentration in hair to the administered dose and the post-mortem concentration in femoral blood. We analyzed hair samples from 22 deceased quetiapine-treated individuals, who were divided into two groups: natural hair colour and dyed/bleached hair. Two to six 1cm long segments were analyzed per individual, depending on the length of the hair, with 6cm corresponding to the last six months before death. The average daily quetiapine dose and average concentration in hair for the last six months prior to death were examined for potential correlation. Estimated doses ranged from 45 to 1040mg quetiapine daily over the period, and the average concentration in hair ranged from 0.18 to 13ng/mg. A significant positive correlation was observed between estimated daily dosage of quetiapine and average concentration in hair for individuals with natural hair colour (p=0.00005), but statistical significance was not reached for individuals with dyed/bleached hair (p=0.31). The individual coefficient of variation (CV) of the quetiapine concentrations between segments ranged from 3 to 34% for individuals with natural hair colour and 22-62% for individuals with dyed/bleached hair. Dose-adjusted concentrations in hair were significantly lower in females with dyed/bleached hair than in individuals with natural hair colour. The quetiapine concentrations in post-mortem femoral blood and in the proximal hair segment, segment 1 (S1), representing the last month before death were also investigated for correlation. A significant positive correlation was observed between quetiapine concentrations in blood at the time of death and concentrations in S1 for individuals with natural hair colour (p=0.003) but not for individuals with dyed/bleached hair (p=0.31). The blood concentrations of quetiapine ranged from 0.006 to 1.9mg/kg, and the quetiapine concentrations in S1 ranged from 0.22 to 24ng/mg. The results of this study suggest a positive correlation of quetiapine between both concentrations in hair and doses, and between proximal hair (S1) and blood concentrations, when conditions such as hair treatments are taken into consideration.

Hair as a Biological Indicator of Drug Use, Drug Abuse or Chronic Exposure to Environmental Toxicants

In recent years hair has become a fundamental biological specimen, alternative to the usual samples blood and urine, for drug testing in the fields of forensic toxicology, clinical toxicology and clinical chemistry. Moreover, hair-testing is now extensively used in workplace testing, as well as, on legal cases, historical research etc. This article reviews methodological and practical issues related to the application of hair as a biological indicator of drug use/abuse or of chronic exposure to environmental toxicants. Hair structure and the mechanisms of drug incorporation into it are commented. The usual preparation and extraction methods as well as the analytical techniques of hair samples are presented and commented on. The outcomes of hair analysis have been reviewed for the following categories: drugs of abuse (opiates, cocaine and related, amphetamines, cannabinoids), benzodiazepines, prescribed drugs, pesticides and organic pollutants, doping agents and other drugs or substances. Finally, the specific purpose of the hair testing is discussed along with the interpretation of hair analysis results regarding the limitations of the applied procedures.

Current advances in biosampling for therapeutic drug monitoring of psychiatric CNS drugs

Many CNS drugs are effective for the treatment of psychiatric disorders. Psychotropic drugs work differently, thus clinical outcomes for many patients may be insufficient. For this reason it could be useful the measurement of drug levels for clinical decision-making. Analytical goals in therapeutic drug monitoring (TDM) should be established by selecting the appropriate biological matrix. The aim of this review is to highlight the usefulness of TDM for antiepileptics, antidepressants and antipsychotics, with a focus on current advances in biosampling. The literature on TDM was reviewed up to March 2015. An overview on the use of alternative biological matrices is provided to address the current issues and advances in the field of biosampling for psychiatric CNS drug TDM.

Screening and quantification of antipsychotic drugs in human brain tissue by liquid chromatography-tandem mass spectrometry: application to postmortem diagnostics of forensic interest

A quantitative LC-MS/MS method has been developed for the simultaneous determination of 17 antipsychotic drugs in human postmortem brain tissue. Sample preparation was performed using Hybrid Solid Phase Extraction-Precipitation technology for the removal of endogenous protein and phospholipid interferences. The chromatographic separation was performed for 16 min on a C8 column, which used a gradient elution of formate ammonium and acetonitrile, and a flow rate gradient. Triple quadrupole mass spectrometry was employed to generate tandem mass spectrometric (MS/MS) data of the target analytes to select the ion m/z signals. Quantitation of the analytes was performed by operating in the dynamic multiple reaction monitoring (dMRM) mode using an electrospray ionization interface. Calibration curves prepared in the spiked brain tissue were linear in the range 20-8000 ng/g (r(2)>0.993) for all drugs (except olanzapine). Within- and between-day coefficients of variation were lower than 25% for all drugs at the LOQ. The LOQ in the matrix ranged between 2 ng/g and 80 ng/g. The method was successfully applied to the unequivocal identification and accurate quantification of antipsychotic drugs in human postmortem brain tissues: therefore, this method can be used in forensic investigations.

Development of a method of clozapine dosage by selective electrode to the iodides

Clozapine (Leponex(®)), the main neuroleptic indicated in the treatment of resistant schizophrenia, requires therapeutic monitoring because of its side effects and the individual variability in metabolism. In addition, several cases of intoxication by this drug were described in the literature. In this work, we studied the indirect dosage of clozapine by selective electrode to the iodides for the optimization of an analytical protocol allowing therapeutic monitoring and the diagnosis of intoxication and/or overdose. Our results showed that the developed method is linear between 0.05 and 12.5 µg/mL (r = 0.980), with a limit of detection of 0.645.10(-3) µg/mL. It presents good precision (coefficient of variation less than 4%) and accuracy (coefficient less than 10%) for all the studied concentrations. With a domain of linearity covering a wide margin of concentrations, this method can be applicable to the dosage of clozapine in tablets and in different biological matrices, such as plasma, urines, and postmortem samples.

Bio-sample preparation and analytical methods for the determination of tricyclic antidepressants

An extended and comprehensive review is presented herein, focusing on sample preparation (pretreatment and extraction) and different analytical methods applied for the quantification of tricyclic antidepressants. These procedures are relevant tools in clinical and forensic toxicology. It is revealed that SPE, for sample preparation, and HPLC, using reversed-phase alkyl (C18) or cyanopropyl-bonded silica columns for the analytes separation, are effective and versatile methods for assay of tricyclic antidepressants. These methods enable achievable detection limits using UV/diode array detection, readily available in most laboratories, down to 1–8 ng ml-1, and using electron capture detection better than 1 ng ml-1, which is lower than that for nitrogen–phosphorus detector. MS interfaced with electrospray ionization offered similar sensitivity, whilst sonic spray ionization provided detection down to 0.03 ng ml-1. A brief discussion on chemical structures, metabolism and mechanism of action of this group of drugs is also presented.

Microwave-assisted hydrolysis and extraction of tricyclic antidepressants from human hair

The objective of this research was to develop, optimize, and validate a modern, rapid method of preparation of human hair samples, using microwave irradiation, for analysis of eight tricyclic antidepressants (TCADs): nordoxepin, nortriptyline, imipramine, amitriptyline, doxepin, desipramine, clomipramine, and norclomipramine. It was based on simultaneous alkaline hair microwave-assisted hydrolysis and microwave-assisted extraction (MAH–MAE). Extracts were analyzed by high-performance liquid chromatography with diode-array detection (HPLC–DAD). A mixture of n-hexane and isoamyl alcohol (99:1, v/v) was used as extraction solvent and the process was performed at 60°C. Application of 1.0 mol L⁻¹ NaOH and microwave irradiation for 40 min were found to be optimum for hair samples. Limits of detection ranged from 0.3 to 1.2 μg g⁻¹ and LOQ from 0.9 to 4.0 μg g⁻¹ for the different drugs. This enabled us to quantify them in hair samples within average therapeutic concentration ranges.

Flow injection determination of benzhexol based on its sensitizing effect on the chemiluminescent reaction of Ce(IV)-sulfite

In this paper, a novel chemiluminescent (CL) method for the determination of benzhexol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic cerium(IV). A mechanism for the CL reaction has been proposed on the basis of CL spectra. Under the optimized conditions, the proposed method allows the measurement of benzhexol hydrochloride over the range 0.1-10 microg/mL with a correlation coefficient of 0.9992 (n = 8), a detection limit of 0.02 microg/mL (3sigma), and a relative standard deviation for 2.0 microg/mL benzhexol (n = 11) of 1.65%. The utility of this method was demonstrated by determining benzhexol hydrochloride in tablets.

Protease inhibitor levels in hair strongly predict virologic response to treatment

OBJECTIVE

Antiretroviral (ARV) therapies fail when behavioral or biologic factors lead to inadequate medication exposure. The currently available methods to assess ARV exposure are limited. Levels of ARVs in hair reflect plasma concentrations over weeks to months, and may provide a novel method for predicting therapeutic responses.

DESIGN/METHODS

The Women's Interagency HIV Study, a prospective cohort of HIV-infected women, provided the basis for developing and assessing methods to measure commonly prescribed protease inhibitors (lopinavir/ritonavir and atazanavir) in small hair samples. We examined the association between hair protease inhibitor levels and initial virologic responses to therapy in multivariate logistic regression models.

RESULTS

ARV concentrations in hair were strongly and independently associated with treatment response for 224 women starting a new protease inhibitor-based regimen. For participants initiating lopinavir/ritonavir, the odds ratio (OR) for virologic suppression was 39.8 [95% confidence interval (CI) = 2.8-564] for those with lopinavir hair levels in the top tertile (>1.9 ng/mg) compared to the bottom (3.4 ng/mg) compared to the lowest (

CONCLUSION

Protease inhibitor levels in small hair samples were the strongest independent predictor of virologic success in a diverse group of HIV-infected adults. This non-invasive method for determining ARV exposure may have particular relevance for the epidemic in resource-poor settings due to the ease of collecting and storing hair.

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Key Words

• hair levels
• therapeutic drug monitoring
• antiretroviral exposure
• virologic response
• protease inhibitors
• atazanavir
• lopinavir
• wihs cohort

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MESH Headings

• Adult
• Atazanavir Sulfate
• CD4 Lymphocyte Count
• Drug Monitoring/methods
• Epidemiologic Methods
• Female
• HIV Infections/drug therapy
• HIV Infections/metabolism
• HIV Infections/virology
• HIV Protease Inhibitors/pharmacokinetics
• HIV Protease Inhibitors/therapeutic use
• Hair/metabolism
• Humans
• Lopinavir
• Middle Aged
• Oligopeptides/pharmacokinetics
• Oligopeptides/therapeutic use
• Patient Compliance
• Pyridines/pharmacokinetics
• Pyridines/therapeutic use
• Pyrimidinones/pharmacokinetics
• Pyrimidinones/therapeutic use
• Ritonavir/pharmacokinetics
• Ritonavir/therapeutic use
• Specimen Handling/methods
• Treatment Outcome
• Viral Load

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Grants

• M01 RR000079 NCRR NIH HHS
• UO1-AI-34994 NIAID NIH HHS
• UO1-AI-34989 NIAID NIH HHS
• U01 AI035004 NIAID NIH HHS
• K23 AI067065 NIAID NIH HHS
• UO1-CH-32632 OID CDC HHS
• U01 AI034989 NIAID NIH HHS
• M01 RR000071 NCRR NIH HHS
• UO1-AI-34993 NIAID NIH HHS
• U01 AI034994 NIAID NIH HHS
• K23 AI067065-03 NIAID NIH HHS
• UO1-AI-42590 NIAID NIH HHS
• U01 AI034993 NIAID NIH HHS
• K23 A1067065 PHS HHS
• MO1-RR-00083 NCRR NIH HHS
• U01 AI031834 NIAID NIH HHS
• UO1-AI-35004 NIAID NIH HHS
• K23 AI067065-02 NIAID NIH HHS
• U01 AI042590-12 NIAID NIH HHS
• MO1-RR-00079 NCRR NIH HHS
• UO1-AI-31834 NIAID NIH HHS
• M01 RR000083 NCRR NIH HHS
• MO1-RR-00071 NCRR NIH HHS
• U01 AI042590 NIAID NIH HHS

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Affiliation(s)

Monica Gandhi Department of Medicine, University of California, San Francisco, San Francisco, California, USA.
Niloufar Ameli
Peter Bacchetti
Stephen J Gange
Kathryn Anastos
Alexandra Levine
Charles L Hyman
Mardge Cohen
Mary Young
Yong Huang
Ruth M Greenblatt

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Using micro-attenuated total reflection spectroscopy to determine chemically induced changes in neat human hair: feasibility study on the effect of antipsychotic drugs

This investigation examines the feasibility of detecting changes in intact human hair upon drug exposure using diamond attenuated total reflection (ATR) infrared spectroscopy. Prior work on microtomed hair has reported spectra changes in the medulla of the hair resulting from drug exposure. This study focuses on examining the hair intact, eliminating sample preparation and thereby reducing the possibility of sample contamination. Several hair samples were first examined to determine whether the lipids in the medulla could be detected from intact hair. Once this was established, hair samples exposed to drugs were investigated to see if changes in those lipids could be detected. Both internal and external drug exposures were investigated: hair samples were externally (incorporated) exposed to Clozapine and real-life samples were obtained from a patient on alprazolam (Xanax). In both cases, spectral differences in the C-H bands were observed in the hairs with drug exposure as compared to hair with no known drug exposure. These changes are consistent with changes in the lipids in the medulla.

Analytical pitfalls in hair testing

This review focuses on possible pitfalls in hair testing procedures. Knowledge of such pitfalls is useful when developing and validating methods, since it can be used to avoid wrong results as well as wrong interpretations of correct results. In recent years, remarkable advances in sensitive and specific analytical techniques have enabled the analysis of drugs in alternative biological specimens such as hair. Modern analytical procedures for the determination of drugs in hair specimens - mainly by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) - are reviewed and critically discussed. Many tables containing information related to this topic are provided.

Examination of a long-term clozapine administration by high resolution segmental hair analysis

The long-term administration of clozapine could be verified by fine segmentation and analysis of single hairs of one person to examine the history of a multiple poisoning case. Segments of 1-2.5mm length were extracted by ultrasonification in 30 microl of the mobile phase (mixture of methanol+water, 50+50). By application of isocratic liquid chromatography and using narrow bore columns (Synergy Polar-RP, Phenomenex), an acceleration and miniaturization of the HPLC-MS-MS assay could be achieved. Total amounts of clozapine down to 30 fg (on column) and its desmethyl metabolite could be analysed in multiple reaction monitoring mode. According to typical sample amounts of approximately 16 microg, relevant hair concentrations higher than 1 pg/mg were detected. Significant and reproducible concentration profiles along the hair fibres revealed characteristic administration cycles. The administration time course - in particular the time of its termination - could be verified with a precision of a few days. The accuracy and reproducibility of the concentration profile was proven based on multiple investigations of single hairs. An individual hair growth rate of 0.55 mm/day was determined with a relative standard deviation of 8% by comparison of concentration profiles in hairs collected after a time span of 165 days.

Simultaneous determination of psychotropic drugs in human urine by capillary electrophoresis with electrochemiluminescence detection

Amitriptyline, doxepin and chlorpromazine are often used as psychotropic drugs in treatment of the various mental diseases, and are also partly excreted by kidney. This work developed a simple, selective and sensitive method for their simultaneous monitoring in human urine using capillary electrophoresis coupled with electrochemiluminescence (ECL) detection based on end-column ECL reaction of tris-(2,2'-bipyridyl)ruthenium(II) with aliphatic tertiary amino moieties. Acetone was used as an additive to the running buffer to obtain their absolute separation. Under optimized conditions the proposed method displayed a linear range from 5.0 to 800 ng mL(-1) for the three drugs with the correlation coefficients more than 0.995 (n=8). Their limits of detection were 0.8 ng mL(-1) (3.6 fg), 1.0 ng mL(-1) (4.5 fg) and 1.5 ng mL(-1) (6.8 fg) at a signal to noise ratio of 3, respectively. The relative standard deviations for five determinations of 20 ng mL(-1) amitriptyline, doxepin and chlorpromazine were 1.7%, 4.2% and 3.6%, respectively. For practical application an extract step with 90:10 heptane/ethyl acetate (v/v) was performed to eliminate the influence of ionic strength in sample. The recoveries of amitriptyline, doxepin and chlorpromazine at different levels in human urine were between 83% and 93%, which showed that the method was valuable in clinical and biochemical laboratories for monitoring amitriptyline, doxepin and chlorpromazine.

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

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

Comparison between micellar liquid chromatography and capillary zone electrophoresis for the determination of hydrophobic basic drugs in pharmaceutical preparations

The determination of highly hydrophobic basic compounds by means of conventional reversed-phase liquid chromatographic methods has several drawbacks. Owing to the characteristics of micellar liquid chromatography (MLC) and capillary electrophoresis (CE), these techniques could be advantageous alternatives to reversed-phase chromatographic methods for the determination of these kinds of compounds. The objective of this study was to develop and compare MLC and CE methods for the determination of antipsychotic basic drugs (amitryptiline, haloperidol, perphenazine and thioridazine) in pharmaceutical preparations. The chromatographic determination of the analytes was performed on a Kromasil C(18) analytical column; the mobile phase was 0.04 m cetyltrimethylammonium bromide (CTAB), at pH 3, containing 5% 1-butanol, at a flow rate of 1 mL/min. The CE separation was performed in a fused-silica capillary with a 50 mm tris-(hydroxymethyl)-aminomethane buffer, pH 7, at an applied voltage of 20 kV, using barbital as internal stardard. The proposed methods are suitable for a reliable quantitation of these compounds in the commercial tablets and drops in terms of accuracy and precision and require a very simple pre-treatment of the samples. By comparing the performance characteristics and experimental details of the MLC and CE methods we conclude that CE seems to be slightly better than MLC in the determination of highly hydrophobic compounds in pharmaceuticals in terms of resolution and economy, taking into account that the limits of detection are not a handicap in pharmaceutical samples.