Trends in bioanalytical methods for the determination and quantification of club drugs: 2000-2010

All solid-state miniaturized potentiometric sensors for flunitrazepam determination in beverages

Flunitrazepam is one of the frequently used hypnotic drugs to incapacitate victims for sexual assault. Appropriate diagnostic tools should be available to victims regarding the growing concern about "date-rape drugs" and their adverse impact on society. Miniaturized screen-printed potentiometric sensors offer crucial point-of-care devices that alleviate this serious problem. In this study, all solid-state screen-printed potentiometric flunitrazepam sensors have been designed. The paper device was printed with silver and carbon ink. Formation of an aqueous layer in the interface between carbon-conducting material and ion-sensing membrane nevertheless poses low reproducibility in the solid-contact electrodes. Accordingly, poly(3,4-ethylenedioxythiophene) (PEDT) nano-dispersion was applied as a conducting hydrophobic polymer on the electrode surface to curb water accumulation. Conditioning of ion-sensing membrane in the vicinity of reference membrane has been considered carefully using special protocol. Electrochemical characteristics of the proposed PEDT-based sensor were calculated and compared favorably to PEDT-free one. The miniaturized device was successfully used for the determination of flunitrazepam in carbonated soft drinks, energy drink, and malt beverage. Statistical comparison between the proposed sensor and official method revealed no significant difference. Nevertheless, the proposed sensor provides simple and user-friendly diagnostic tool with less equipment for on-site determination of flunitrazepam.

[Knockout Drugs: Diagnostics in the Emergency Unit and Clinical Practice]

Knockout Drugs: Diagnostics in the Emergency Unit and Clinical Practice Abstract. Every now and then, physicians are challenged with date rape drugs. If there is a suspicion of substance administration, the question of involving forensic medicine is commonly raised. In obscure situations or questionable offences, however, patients may wish for an initial diagnosis in the emergency department or the private practice. The physicians are often greatly challenged by the variety of substances, the limited analytical methods and difficulties with the interpretion of results. The major goal of this article is to present diagnostic options including their limitations. An overview of frequently involved substances is provided. Particular focus will be placed on practical aspects, including questions regarding pre-analytics and health insurance coverage.

Metal organic framework based carbon porous as an efficient dispersive solid phase extraction adsorbent for analysis of methamphetamine from urine matrix

Carboxylated carbon porous adsorbent was derived from zeolite imidazole framework (ZIF-8) via carbonization of ZIF-8 under a nitrogen atmosphere. The synthesized carboxylated adsorbent was fully characterized by various techniques including Fourier transform spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and zeta potential analysis. The carboxylated adsorbent was applied as dispersive solid phase extraction (DSPE) adsorbent for efficient extraction of methamphetamine (MET) from biological urine samples. Several extraction parameters influencing the extraction efficiency were investigated and the calibration curve was plotted under optimized conditions in urine media. The method showed a good linearity in the range of 50-2500 ng/mL. The limit of detection (LOD) and limit of quantification (LOQ) was 10 and 35.80 ng/mL, respectively. A satisfactory analysis of the positive real samples with the recovery of 99.83% confirms the applicability of the proposed method in different clinical and forensic laboratories.

Ketamine and norketamine stability in whole blood at ambient and 4°C conditions

A study was implemented to describe the pharmacokinetics (PK) of ketamine (K) and its metabolite norketamine (NK) in critically ill adults. Conducting studies in these subjects is hindered by the immediate need to process and freeze samples obtained in a busy intensive care setting. The ability to store unprocessed samples at room temperature for an extended time period would overcome this barrier. Stability and blood to plasma partitioning of K and NK were investigated in whole blood for up to 120 h at room temperature and 4°C. Whole blood was spiked with K and NK (1000 ng/mL each). Blood samples were aliquoted at different time points (0-120 h), extracted and analyzed using a validated high-performance liquid chromatography tandem mass spectrometry assay. The study demonstrated the stability of both K and NK in whole blood up to 120 h. These in vitro studies suggest that the concentrations of K and NK measured in the PK samples are reliable. The established stability results were successfully employed to investigate K and NK pharmacology studies in critically ill adults.

Rapid analysis of drugs of abuse and their metabolites in human urine using dilute and shoot liquid chromatography-tandem mass spectrometry

Liquid chromatography-tandem mass spectrometric method for analysis of 113 abuse drugs and their metabolites in human urine was developed and validated. A simple sample clean-up procedure using the "dilute and shoot" approach, followed by reversed phase separation, provided a fast and reliable method for routine analysis. Drugs were separated in a Capcell Pak MG-III C₁₈ column using a gradient elution of 1 mM ammonium formate with 0.1% formic acid in water and acetonitrile. The total time for analysis was 32 min. The multiple reaction monitoring mode using two transitions (e.g., quantifier and qualifier) was optimized for both identification and determination. The calibration curves for each analyte were linear over the concentration ranges of 1-100, 5-100, or 10-100 ng/mL using 400 μL of human urine sample with the coefficient of determination above 0.9921. The coefficient of variation and accuracy for the intra- and inter-assays of the tested drugs at three QC levels were 1.1-14.6 and 86.7-106.8%, respectively. The present method was successfully applied to the analysis of forensic urine samples obtained from 17 drug abusers. This method is useful for the rapid and accurate determination of multiple drug abuse with a small amount of urine in forensic and clinical toxicology.

Intoxication of a Young Girl Reveals the Pitfalls of GHB Rapid Screening

The authors discuss the case of a 14-year-old girl who was transferred to the ICU of our hospital with ethanol intoxication (3.3 g/L), loss of consciousness (E5M3V1), and severe amnesia on recovery that was suspected of gamma-hydroxybutyric acid (GHB) intoxication. STAT toxicology screening may be necessary, when sexual assault under GHB intoxication is suspected. Therefore, the initial analysis of a urine sample was performed with a new enzymatic assay analysis for GHB. The enzymatic assay reported a GHB concentration of 26 mg/L, which is above the cut-off value of 10 mg/L. This cut-off value is to differentiate endogenous and exogenous levels because low levels of GHB occur naturally in the body. However, confirmation of these results by gas chromatography, which is common practice to confirm a positive GHB, gave a negative result. This discrepancy is probably contributed to interference of ethanol with the assay. This is a substantial downside of the GHB rapid screening, since the combination of GHB and ethanol is common. It is therefore advised to confirm that the positive GHB results are lower than 50 mg/L by gas chromatography, when using the rapid screening. This way the false-positive results and consequent inappropriate social and legal actions may be avoided.

Ionic-liquid-based dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the forensic determination of methamphetamine in human urine

Determination of methamphetamine in forensic laboratories is a major issue due to its health and social harm. In this work, a simple, sensitive, and environmentally friendly method based on ionic liquid dispersive liquid-liquid microextraction combined with high-performance liquid chromatography was established for the analysis of methamphetamine in human urine. 1-Octyl-3-methylimidazolium hexafluorophosphate with the help of disperser solvent methanol was selected as the microextraction solvent in this process. Various parameters affecting the extraction efficiency of methamphetamine were investigated systemically, including extraction solvent and its volume, disperser solvent and its volume, sample pH, extraction temperature, and centrifugal time. Under the optimized conditions, a good linearity was obtained in the concentration range of 10-1000 ng/mL with determination coefficient >0.99. The limit of detection calculated at a signal-to-noise ratio of 3 was 1.7 ng/mL and the relative standard deviations for six replicate experiments at three different concentration levels of 100, 500, and 1000 ng/mL were 6.4, 4.5, and 4.7%, respectively. Meanwhile, up to 220-fold enrichment factor of methamphetamine and acceptable extraction recovery (>80.0%) could be achieved. Furthermore, this method has been successfully employed for the sensitive detection of a urine sample from a suspected drug abuser.

Determination of GHB and its precursors (GBL and 1,4-BD) in dietary supplements through the synthesis of their isotopologues and analysis by GC-MS method

Gamma-hydroxybutyric acid (GHB) and its "pro-drugs", gamma-butyrolactone (GBL) and 1,4 butanediol (1,4-BD), are drugs of abuse with depressant effects on the central nervous system. Many analytical methods have been proposed for the quantitative determination of these compounds mainly in biological matrices but only few have been addressed to dietary supplements and foods. Facile synthesis of the GBL and 1,4-BD isotopologues are available by "one pot" Ru-catalyzed homogeneous deuteration of dicarboxylic acids. In this work we propose a new method for determination of GHB, GBL and 1,4-BD in commercially available dietary supplements, based on isotope dilution mass spectrometry (ID-MS). The procedure involves a simple extraction of sample with acidic acetonitrile and direct analysis by GC-ID-MS method without any purification or derivatization. Indeed, the proposed method takes advantage of the complete conversion of GHB (free acid or its salts) to GBL, allowing the quantification of GHB and its pro-drugs. Five levels for each calibration curve have been prepared by diluting working solutions of the analytes to obtain concentrations ranging from 1 to 20mg/mL. The validation procedures have shown an accuracy between 88% and 99% and a precision between 7.3% and 2.9% of each analyte in the sample matrix. Positive ions chemical ionization (PICI) have been employed to preserve the information on molecular ions and to improve specificity and sensitivity of quantitative determination.

Delirious mania: detection, diagnosis, and clinical management in the acute setting

Delirious mania is a severe but under-recognized neuropsychiatric syndrome characterized by the rapid onset of delirium, mania, and psychosis, not associated with a prior toxicity, physical illness, or mental disorder. Catatonia is often a prominent feature of the syndrome. While initially believed to be rare, recent reports suggest that delirious mania may constitute up to 15% of all acute mania cases. When delirious mania is unrecognized or improperly treated, it can progress rapidly in severity and can become life-threatening. This article reviews the pathophysiology, diagnosis, and treatment of delirious mania and includes a detailed case report. Delirious mania is robustly responsive to high-dose lorazepam or electroconvulsive therapy (ECT); thus, early recognition and definitive treatment can be life-saving.

Enzymatic assay for GHB determination in forensic matrices

Current procedures for the determination of gamma-hydroxybutyric acid (GHB) require time-consuming extraction and derivatization steps before chromatographic detection, making a high-throughput alternative desirable. Bühlmann Laboratories offers an enzymatic assay for the quantitative determination of GHB in urine and serum. We report the adaptation of this photometric assay to the Thermo Scientific MGC-240 analyzer and its use in the determination of GHB in forensic matrices including urine, whole blood and vitreous humour. Most matrices require only a brief centrifugation before analysis, while blood requires an additional protein precipitation step. A variety of cases (sexual assaults, impaired drivers and death investigations) have been analyzed alongside the gas chromatography-mass spectrometry (GC-MS) reference method. Correlation with the GC-MS has been found to be acceptable, with no false negatives and few false positives, although postmortem samples appear more prone to testing false positive than do antemortem samples. Simple sample preparation and high throughput allow for a significant reduction in analysis time relative to chromatographic methods. This assay is used as a screening method in our laboratory, with a quantitative GC-MS method serving for the confirmation of positive results. To our knowledge, this represents the first evaluation of an enzymatic assay for GHB in a forensic context.

Determination of γ-hydroxybutyrate (GHB), β-hydroxybutyrate (BHB), pregabalin, 1,4-butane-diol (1,4BD) and γ-butyrolactone (GBL) in whole blood and urine samples by UPLC-MSMS

The demand of high throughput methods for the determination of gamma-hydroxybutyrate (GHB) and its precursors gamma-butyrolactone (GBL) and 1,4-butane-diol (1,4BD) as well as for pregabalin is increasing. Here we present two analytical methods using ultra-high pressure liquid chromatography (UPLC) and tandem mass spectrometric (MS/MS) detection for the determination of GHB, beta-hydroxybutyrate (BHB), pregabalin, 1,4BD and GBL in whole blood and urine. Using the 96-well formate, the whole blood method is a simple high-throughput method suitable for screening of large sample amounts. With an easy sample preparation for urine including only dilution and filtration of the sample, the method is suitable for fast screening of urine samples. Both methods showed acceptable linearity, acceptable limits of detection, and limits of quantification. The within-day and between-day precisions of all analytes were lower than 10% RSD. The analytes were extracted from matrices with recoveries near 100%, and no major matrix effects were observed. Both methods have been used as routine screening analyses of whole blood and urine samples since January 2010.