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A carboxyl functionalized organic-inorganic hybrid monolithic column (TMOS-co-CES) was applied as in-tube solid-phase microextraction (SPME) sorbent combining with ultra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometer for separation and analyzation of seven typical amphetamine-type stimulants (ATSs), including amphetamine (AM), methamphetamine (MAM), cathinone, methcathinone, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyethylamphetamine. The application potential of TMOS-co-CES material to ATSs was preliminarily confirmed by computational simulation by using cathinone as a representative. The influences of various SPME parameters and analytical performance were investigated systematically. As matched with the results of computational simulation, TMOS-co-CES column could capture ATSs under milder near neutral pH condition with high extraction efficiency basing on the adsorption mechanism explained as a mixed mode of electrostatic and hydrophobic interactions. Seven target trace ATSs in spiked sewage, pond water and urine could be rapidly and conveniently separated and enriched by the proposed TMOS-co-CES in-tube SPME method under the optimized conditions with good accuracy, repeatability and resistance to matrix interference. Moreover, AM and MAM had been successfully detected in real urines of suspected drug abusers by TMOS-co-CES in-tube SPME method, which indicated that the proposed method had good application feasibility for drug monitoring. The mild extraction condition and ideal method performance further made the TMOS-co-CES in-tube SPME method more potential in applications for forensic analysis and drug abuse., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this paper, cascade membrane technology was utilized to classify polysaccharides from Ganoderma lucidum (GLPs). The properties and antifatigue activity of graded polysaccharides were identified and compared. GLPs were separated using cascade ultrafiltration membranes of 100 kDa, 10 kDa and 1 kDa in sequence. The molecular weights of polysaccharides in these GLP fractions were approximately 322.0 kDa, 18.8 kDa and 6.4 kDa, and all polysaccharides were in active β-configurations. This showed that all graded GLPs could elongate swimming time, improve endurance and promote fatigue recovery, especially polysaccharides with molecular weights above 10 kDa. This demonstrated that GLPs could decrease the activities of SUN and CK and the levels of MDA and BLA. They also increased the level of Gly, accelerated fat transformation, and improved the activities of GPx, SOD and LDH in all treated mice. Accordingly, GLPs above 10 kDa might be potential agents with antifatigue activity., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction: Catha edulis (Vahl) Forssk. ex Endl. (Celestraceae) is used as a recreational drug on daily basis for its euphoric and psychostimulant effects. It is also chewed by individuals who are on medications, raising the possibility of drug-khat interaction. However, limited data are available in the literature, although clinically significant interactions are expected, as khat contains a complex mixture of pharmacologically active constituents., Areas Covered: It provides an overview of the phytochemistry, pharmacokinetics, pharmacodynamics, and pharmacogenetics of khat based on the literature mined from PubMed, Google Scholar, and Cochrane databases. It also presents a detailed account of drug-khat interactions with specific examples and their clinical significance. The interactions mainly occur at the pharmacokinetics level and particular attention is paid for the phases of absorption and cytochrome P450 enzyme-mediated metabolism., Expert Opinion: Despite the increasing trend of khat chewing with medications among the populace and the potential risk for the occurrence of clinically significant interactions, there is paucity of data in the literature demonstrating the magnitude of the risk. The available data, however, clearly demonstrate that the consequence of drug-khat interaction is dependent on genotype. Genotyping, where feasible, could be used to improve clinical outcome and minimize adverse reactions.

Caffeine, a natural stimulant, is known to be effective for weight loss. On this basis, we screened the arousal-inducing effect of five dietary supplements with a weight loss effect ( Garcinia cambogia , Coleus forskohlii , Camellia sinensis L., Irvingia gabonensis , and Malus pumila M.), of which the G. cambogia peel extract (GC) showed a significant arousal-inducing effect in the pentobarbital-induced sleep test in mice. This characteristic of GC was further evaluated by analysis of electroencephalogram and electromyogram in C57L/6N mice, and it was compared to that of the positive control, caffeine. Administration of GC (1500 mg/kg) significantly increased wakefulness and decreased non-rapid eye movement sleep, similar to that of caffeine (25 mg/kg), with GC and caffeine showing a significant increase in wakefulness at 2 and 6 h, respectively. Compared to that of caffeine, the shorter duration of efficacy of GC could be advantageous because of the lower possibility of sleep disturbance. Furthermore, the arousal-inducing effects of GC (1500 mg/kg) and caffeine (25 mg/kg) persisted throughout the chronic (3 weeks) administration study. This study, for the first time, revealed the arousal-inducing effect of GC. Our findings suggest that GC might be a promising natural stimulant with no side effects. In addition, it is preferential to take GC as a dietary supplement for weight loss during the daytime to avoid sleep disturbances owing to its arousal-inducing effect.

New psychoactive substances (NPS) can be divided into two main groups: synthetic molecules and active principles of natural origin. With respect to this latter group, a wide range of alkaloids contained in plants, mainly from Asia and South America, can be included in the class of NPS of natural origin. The majority NPS of natural origin presents stimulant and/or hallucinogenic effects (e.g. Catha edulis and Ayahuasca, respectively) while few of them show sedative and relaxing properties (e.g. kratom). Few information is available in relation to the analytical identification of psychoactive principles contained in the plant material. Moreover, to our knowledge, scarce data are present in literature, about the characterization and quantification of the parent drug in biological matrices from intoxication and fatality cases. In addition, the metabolism of natural active principles has not been yet fully investigated for most of the psychoactive substances from plant material. Consequently, their identification is not frequently performed and produced metabolites are often unknown. To fill this gap, we reviewed the currently available analytical methodologies for the identification and quantification of NPS of natural origin in plant material and, whenever possible, in conventional and non-conventional biological matrices of intoxicated and dead subjects. The psychoactive principles contained in the following plants were investigated: Areca catechu, Argyreia nervosa, Ayahuasca, Catha edulis, Ipomoea violacea, Mandragora officinarum, Mitragyna speciosa, Pausinystalia yohimbe, Piper methisticum, Psilocybe, Rivea corymbosa, Salvia divinorum, Sceletium tortuosum, Lactuca virosa. From the results obtained, it can be evidenced that although several analytical methods for the simultaneous quantification of different molecules from the same plants have been developed and validated, a comprehensive method to detect active compounds from different natural specimens both in biological and non-biological matrices is still lacking., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The effectiveness of decontamination procedures used for the removal of external drug contamination in forensic hair analysis is an ongoing debate. This investigation evaluated wash methods complying with Society of Hair Testing (SoHT) guidelines and their capacity to remove cocaine (COC) and methamphetamine (MA) from artificially contaminated hair. The most effective decontamination method was determined using a systematic approach, involving (1) an initial washing solvent screen, (2) optimization of wash duration, (3) comparison of sequential wash methods, and (4) reanalysis of clinical hair samples. For analysis, hair was subjected to micro-pulverized methanolic extraction prior to quantitation by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Methanol (MeOH) and 0.1 M phosphate buffer (pH 6) were the most effective organic and aqueous solvents, respectively, removing 28%-38% of COC and 16%-31% of MA. Wash durations longer than 30-60 minutes did not remove additional amounts, and a more efficient sequential wash method was subsequently developed. Despite this, the interpretation of reportable results relative to the SoHT cut-off levels was unchanged for most clinical hair samples reanalyzed after washing by agitation for 30 minutes with MeOH. These findings highlight the inability of decontamination solvents to completely remove external COC and MA contamination from hair, including wash methods adhering to SoHT guidelines., (© 2019 John Wiley & Sons, Ltd.)

A nano graphene oxide sol-gel composite (NGO/sol-gel) applied as a coating of a capillary glass tube stir bar to develop a novel stir bar sorptive extraction (SBSE) method for simultaneous extraction of amphetamine (AMP) and methamphetamine (MET) from biological urine sample. Lab-synthesized NGO was applied with methyltrimethoxysilane (MTMOS) and Tetraethoxysilane (TEOS) as sol-gel precursor. NGO/sol-gel was deposited on the surface of a capillary glass tube to prepare stir bar sorptive extraction adsorbent by a simple and fast method. The scanning electron micrograph images showed a three dimensional structure of lab-made device suitable for SBSE method for simultaneous extraction of AMP and MET. Effective extraction parameters were investigated. Through studied suitable extraction conditions, satisfactory linearity was achieved in the concentration range of 50-2000 ngmL - 1 for AMP and 40-2500 ngmL - 1 for MET. The relative recovery of the analytes were 99.5 and 99.7% for AMP and MET, respectively for positive urine samples were studied by novel introduced method. The results cleared that NGO/sol-gel composite could be used as practical method in laboratories as an efficient SBSE adsorbent for drugs determination in urine matrix., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A methamphetamine-based molecularly imprinted polymer (MIP) has been prepared by bulk polymerization to recognize new psychoactive substances (NPS) of the amphetamine, cathinones and 2C families in oral fluid samples, being the first precedent of a synthetized MIP for the extraction and preconcentration 32 NPS including amphetamine type substances and synthetic cathinones from oral fluids. Pre-polymerization complex and resulting materials were appropriately characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption isotherms. Appropriateness of the material for the specific recognition of the target analytes was also evaluated through computational calculations and experimentally assessed by solid phase extraction (SPE). The most appropriate SPE conditions were evaluated and recoveries of 32 different NPS were obtained, ranging from 80 to 120% with a relative standard deviation (RSD) in all cases lower than 12%. Amphetamine-related NPS were analyzed by a fast and portable methodology based on ion mobility spectrometry (IMS) and a rearguard procedure based on ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS) providing limit of detection values from 10 to 80 μg L -1 and from 0.03 to 1.3 μg L -1 , respectively. Oral fluid samples, containing different interferents like caffeine, fluticasone and cetirizine, were spiked with 300 μg L -1 amphetamine and subsequently analyzed, showing recoveries ranging from 81 to 115% using both methodologies. Thus, this paper shows preliminary results to demonstrate the applicability of the developed procedure which could be used with minor modifications as screening technique in on-road drug analysis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In the present study, a sulfonic acid functionalized enantio-selective resinous material was developed for effective chiral separation of (±)-methamphetamine racemate. R-methamphetamine-sulfonamide phenolic derivative was first prepared and fully characterized utilizing instrumental and spectroscopic techniques, then the sulfonamide was implemented in an acid catalyzed condensation copolymerization with phenol and formaldehyde. The resulted resinous material was then exposed to successive alkaline and acidic treatments in order to remove the R-methamphetamine enantiomer out of the resin matrix and obtaining the molecularly imprinted enantio-selective material, which was also investigated by scanning electron microscope, FTIR and XPS spectroscopy. The maximum selective extraction of the R-methamphetamine enantiomer was achieved at pH 7. The adsorption isotherms indicated an adsorption capacity of 233 ± 1 mg/g and followed the well-known Langmuir model. Also, the enantio-separation experiment of the racemic mixture was performed by column technique and both the supernatant loading and the eluant recovery solutions indicated an enantiomeric excess of 80% and 67% related to S- and R-methamphetamine, respectively., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A novel pH-responsive block copolymer (Poly ethylene glycol-b-poly (N,N-dimethylaminoethylmethacrylate-co-maleic acid) was designed for the decoration and stabilization of magnetic nanoparticles (MNPs) as an efficient magnetic nano adsorbent for extraction of amphetamine (AM) from biological urine samples to be determined by high performance liquid chromatography-ultra violet detector (HPLC-UV). Full characterization of the synthesized polymeric magnetic nanoparticles (PMNPs) were followed by various techniques like Fourier transform infrared (FT-IR) spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). Important extraction parameters including pH, amount of sample volume, amount of adsorbent, type and amount of extraction organic solvent, time of extraction and desorption, agitation rate (rpm), and ionic strength of the extraction medium were studied and optimized. Under optimized extraction conditions, good linearity was observed in the concentration range of 30-2000 ng/mL for AM. The amount of the q e was calculated as 0.18 (mg/g). The method was applied in determination of AM from positive urine samples with the recovery of 99.84%. Results indicated that the proposed method could be applied in clinical and forensic laboratories for simple, selective, and fast determination of AM from urine samples., (Copyright © 2017 John Wiley & Sons, Ltd.)

Ethnopharmacological Relevance: Kratom (Mitragyna speciosa Korth.) from the Rubiaceae family is an indigenous tropical medicinal tree of Southeast Asia. Kratom leaves have been used for decades in Malaysia and Thailand in traditional context for its perceived vast medicinal value, and as a mild stimulant among manual labourers. Kratom consumption has been reported to cause side-effects in kratom users., Aim of the Study: To evaluate kratom's effects towards hematological and clinical-chemistry parameters among regular kratom users in Malaysia., Methods: A total of 77 subjects (n=58 regular kratom users, and n=19 healthy controls) participated in this cross-sectional study. All the surveys were conducted through face-to-face interview to elicit subject's socio-demographic characteristics and kratom use history. A full-blood test was also administered. Laboratory analysis was conducted using GC-MS to determine mitragynine content in the acquired kratom samples in order to relate mitragynine consumption with possible alterations in the blood parameters of kratom users., Results: Findings showed that there were no significant differences in the hematological and clinical-chemistry parameters of traditional kratom users and healthy controls, except for HDL and LDL cholesterol values; these were found to be above the normal reference range for the former. Similarly, long-term kratom consumption (>5 years), and quantity of daily kratom use (≥3 ½ glasses; mitragynine content 76.3-114.8mg) did not appear to alter the hematological and biochemical parameters of kratom users., Conclusion: These data suggest that even long-term and heavy kratom consumption did not significantly alter the hematological and clinical-chemistry parameters of kratom users in a traditional setting., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Fatigue is a common and serious health problem, and various dietary interventions have previously been employed to ameliorate fatigue. The aim of the current study was to investigate the anti‑fatigue effects of Danish porcine placenta (DPP) and its major dipeptides, including leucine‑glycine (LG) and glycine‑leucine (GL). The anti‑fatigue effects of orally administered DPP, LG and GL were determined using a treadmill exercise test and a forced swimming test (FST) in mice. Additionally, the anti‑inflammatory effects of DPP, LG and GL were investigated in activated splenocytes. The results demonstrated that oral treatment of mice with DPP, LG and GL increased the time to exhaustion during treadmill exercise. Furthermore, DPP, LG and GL enhanced the levels of dopamine, brain‑derived neurotrophic factor and phosphorylated-extracellular signal‑regulated kinase in the brains of mice with treadmill exercise‑induced exhaustive fatigue, and decreased levels of certain proinflammatory cytokines in the serum and spleen, as determined by ELISA and western blot analysis. Following treadmill exercise, commercial kits were employed to demonstrate that DPP, LG and GL reduced the levels of lactate dehydrogenase, lactate, creatine kinase, blood urea nitrogen, alanine transaminase and aspartate transaminase in the muscle and/or serum of mice. In addition, DPP, LG and GL enhanced the muscle and liver glycogen levels, catalase activity in the liver and serum superoxide dismutase activity. DPP, LG and GL also increased the proliferation of splenocytes and inhibited proinflammatory cytokine production by reducing the activation of caspase‑1 and nuclear factor‑κB in activated splenocytes, as determined by MTT assays, ELISA and western blotting, respectively. Furthermore, DPP, LG and GL reduced immobility time in the FST in mice. In conclusion, DPP may limit intensive exercise‑induced fatigue by increasing dopaminergic systems and inhibiting inflammatory responses.

The utility of diode array ultraviolet (UV) detection for aiding in the identification of synthetic cathinones, including different sub-classes and positional isomers is presented. For 35 synthetic cathinones, unique UV spectra are obtained for seven sub-classes, including mostly beta ketones, where position and type of substitution on benzene rings give rise to differences in UV maxima and relative intensity of the spectral bands. This aspect is key to distinguishing positional isomers that contain differences in R substitution (mono and di) around the benzene ring, which provides complementary information to electron ionization mass spectrometry, where the latter technique cannot distinguish between these types of positional isomers. In addition, it is possible to ascertain the substitution position based on the UV spectra. For ten sets of positional isomers, it was possible to distinguish most of the positional isomers within a set. For ultra-high performance supercritical fluid chromatography (UHPSFC) versus reversed phase ultra-high performance liquid chromatography (UHPLC), there was at least a 10 nm blue shift in UV maximum (shift to shorter wavelengths). This highlights the importance of taking in account the effect of mobile phase on the UV maximum when performing method development in UHPSFC. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Separation and identification of positional isomers is an important issue in forensic toxicology, particularly in the context of new psychoactive substances (NPS). Despite the structural similarity, positional isomers often show different pharmacological properties and thus can exhibit dramatic differences with respect to their toxicity. Additionally, besides these pharmacological and toxicological effects, the legal status is also of great importance. We present a sensitive and selective LC-MS/MS method to separate the ortho, meta and para isomers of methylmethcathinone (MMC) and methylethcathinone (MEC) using a core-shell biphenyl analytical column. Reliability of the method was confirmed under consideration of the validation parameters selectivity, linearity, accuracy and precision, analytical limits, processed sample stability, matrix effects and recovery. Linearity was demonstrated over the entire calibration range from 5 to 250ng/ml with the use of a 1/x 2 weighting. Appropriate quantification and detection limits (LLOQ=5ng/ml, LOD<2ng/ml) could be achieved. Application of the method to real serum samples collected between June 2014 and August 2016 revealed the proof of a recent MMC or MEC consumption, respectively, in eight cases. Isomers of MMC could be detected in three of these eight cases, of which two were positive for 3-MMC and one was positive for 2-MMC. The other samples were tested positively for 3-MEC. In none of the samples 4-MMC, 2-MEC or 4-MEC could be detected. Only substances that were not governmentally controlled at that time could be detected, reflecting the rapid response of the recreational drug market to newly enacting drug laws., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Chromatographic differentiation of the ring-substituted regioisomers of amphetamine (AMP) and methamphetamine (MA) was performed by supercritical fluid chromatography (SFC). The behaviour of the retention against the changes of column temperature and co-solvent proportion was studied. The obtained information facilitated the optimization of the each regioisomer. As a result, 2-, 3-, and 4-ring-substituted analogues of AMP and MA with methyl, methoxy, fluoro, chloro, and bromo groups were separated, generally within 6 min. In addition, we found that the separation pattern of the examined regioisomers was classified into two, which depended on the electron donating/withdrawing effect of the substituent. Our results indicate that SFC could be used in forensic drug analysis for fast, reliable identification of structurally similar drugs of abuse. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

An advantage of differential mobility spectrometry (DMS) is it provides an orthogonal mechanism to mass spectrometry (MS). The DMS-MS/MS detects analytes in the gas phase on the basis of differences in ion mobility in low and high electric fields, which makes DMS-MS/MS an alternative to chromatographic separation-MS. One drawback of DMS is its limited resolution and sensitivity, especially for detecting small molecules when using a nonpolar inert gas as the carrier gas. The present work has evaluated the effects on peak capacity of adding chemical modifiers to inert carrier gases (nitrogen, helium, argon and carbon dioxide). Use of a methanol-helium mixture gave improvements in both separation and sensitivity. Nine structurally similar amphetamine-type stimulants were determined in urine without pretreatment of the samples before analysis. After optimization of carrier gas, nature and concentration of chemical modifier, and DMS temperature, limits of detection ranging from 1.1 to 2.7 ng mL -1 , with a linear range of three orders of magnitude (5-5000 ng mL -1 ) were achieved. Precision was <15% and the accuracy of the quality control samples was 87.6-113.7%. For the quantitation of urine samples from drug abusers, data obtained using DMS-MS/MS showed reasonable agreement (within ±19.5%) with that obtained using LC-MS/MS. The analysis time for DMS-MS/MS was only 1.1 min and a paired sample t-test between the two methods gave a p-value of 0.0894, which indicates that DMS-MS/MS is a reliable method, with comparable precision and sensitivity to LC-MS/MS., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The amphetamine isomer β-methylphenylethylamine (BMPEA) was first synthesized in the early 1930s, but its efficacy and safety in humans has not been studied. Recently, the United States Food and Drug Administration (FDA) detected BMPEA in dietary supplements labelled as containing Acacia rigidula. Over a year after the FDA reported its findings, we analyzed Acacia rigidula dietary supplements to determine if BMPEA had been removed. Supplements were analyzed using liquid chromatography-quadrupole time-of-flight mass spectrometry. Diluted methanolic extract from each supplement was run three times and each data set obtained was analyzed using Agilent MassHunter Qualitative Analysis. The presence of BMPEA was confirmed by accurate mass, retention time and mass spectra match against a reference standard. Quantification of BMPEA was determined using an eight-point calibration curve of spiked standard to a matrix blank. Twenty-one brands of Acacia rigidula supplements were analyzed. More than half (11/21; 52.4%) of the Acacia rigidula supplement brands contained BMPEA. The stimulant was present at quantities such that consumers following recommended maximum daily servings would consume a maximum of 93.7 mg of BMPEA per day. Consumers of Acacia rigidula supplements may be exposed to pharmacological dosages of an amphetamine isomer that lacks evidence of safety in humans. The FDA should immediately warn consumers about BMPEA and take aggressive enforcement action to eliminate BMPEA in dietary supplements. Copyright © 2015 John Wiley & Sons, Ltd., (Copyright © 2015 John Wiley & Sons, Ltd.)

The electrochemical oxidation of caffeine, a widely over-the-counter stimulant drug, has been investigated in effluent wastewater and deionized water (DIW) using graphite-poly vinyl chloride (PVC) composite electrode as anode. Effects of initial concentration of caffeine, chloride ion (Cl(-)) loading, presence of hydrogen peroxide (H2O2), sample volume, type of sample and applied voltage were determined to test and to validate a kinetic model for the oxidation of caffeine by the electrochemical oxidation process. The results revealed that the electrochemical oxidation rates of caffeine followed pseudo first-order kinetics, with rate constant values ranged from 0.006 to 0.23 min(-1) depending on the operating parameters. The removal efficiency of caffeine increases with applied voltage very significantly, suggesting a very important role of mediated oxidation process. However, the consumption energy was considered during electrochemical oxidation process. In chloride media, removal of caffeine is faster and more efficiently, although occurrence of more intermediates takes place. The study found that the adding H2O2 to the NaCl solution will inhibit slightly the electrochemical oxidation rate in comparison with only NaCl in solution. Liquid chromatography-time of flight-mass spectrometry (LC-TOF-MS) technique was applied to the identification of the by-products generated during electrochemical oxidation, which allowed to construct the proposed structure of by-products., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A simple and inexpensive method for the identification of four substituted amphetamines, namely, 3,4-methylenedioxy methamphetamine (MDMA), methamphetamine (MA), 3,4-methylenedioxy amphetamine (MDA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) was developed using an in-house constructed semi-automated portable capillary electrophoresis instrument (CE) with capacitively coupled contactless conductivity detection (C(4)D). Arginine 10mM adjusted to pH4.5 with acetic acid was found to be the optimal background electrolyte for the CE-C(4)D determination of these compounds. The best detection limits achieved with and without a sample preconcentration process were 10ppb and 500ppb, respectively. Substituted amphetamines were found in different seized illicit club drug tablets and urine samples collected from different suspected users. Good agreement between results from CE-C(4)D and those with the confirmation method (GC-MS) was achieved, with correlation coefficients for the two pairs of data of more than 0.99., (Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.)

Porous graphitic carbon (PGC) is an increasingly popular and attractive phase for HPLC on account of its chemical and thermal stability, and its unique separation mechanism. However, native PGC is strongly hydrophobic and in some instances excessively retentive. As part of our effort to build a library of hydrophilic covalently modified PGC phases, we functionalized PGC with catechol and amide groups by means of aryl diazonium chemistry to produce two new phases. Successful grafting was confirmed by X-ray photoelectron spectroscopy (XPS). Under HILIC conditions, the Catechol-PGC showed up to 5-fold increased retention relative to unmodified PGC and selectivity that differed from four other HILIC phases. Under reversed phase conditions, the Amide-PGC reduced the retentivity of PGC by almost 90%. The chromatographic performance of Catechol-PGC and Amide-PGC is demonstrated by separations of nucleobases, nucleosides, phenols, alkaline pharmaceuticals, and performance enhancing stimulants. These compounds had retention factors (k) ranging from 0.5 to 13., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Methamphetamine is a widely abused psychostimulant containing a chiral center. Consumption of over-the-counter and prescription medications may yield positive amphetamines results, but chiral separation of l- and d-methamphetamine and its metabolite amphetamine can help determine whether the source was licit or illicit. We present the first LC-MS/MS method with precolumn derivatization for methamphetamine and amphetamine chiral resolution in plasma and oral fluid collected with the Oral-Eze(®) and Quantisal™ devices. To 0.5mL plasma, 0.75mL Oral-Eze, or 1mL Quantisal specimen racemic d11-methamphetamine and amphetamine internal standards were added, followed by protein precipitation. Samples were centrifuged and supernatants loaded onto pre-conditioned Phenomenex(®) Strata™-XC Polymeric Strong Cation solid phase extraction columns. After washing, analytes were eluted with 5% ammonium hydroxide in methanol. The eluate was evaporated to dryness and reconstituted in water. Derivatization was performed with 1-fluoro-2,4-dinitrophenyl-5-l-alanineamide (Marfey's reagent) and heating at 45°C for 1h. Derivatized enantiomer separations were performed under isocratic conditions (methanol:water, 60:40) with a Phenomenex(®) Kinetex(®) 2.6μm C18 column. Analytes were identified and quantified by two MRM transitions and their ratio on a 3200 QTrap (AB Sciex) mass spectrometer in ESI negative mode. In all three matrices, the method was linear for all enantiomers from 1 to 500μg/L, with imprecision and accuracy of ≤11.3% and 85.3-108%, respectively. Extraction efficiencies ranged from 67.4 to 117% and matrix effects from -17.0 to 468%, with variation always ≤19.1%. Authentic plasma and OF specimens were collected from an IRB-approved study that included controlled Vicks(®) VapoInhaler™ administration. The present method is sensitive, selective, economic and rapid (separations accomplished in <10min), and improves methamphetamine result interpretation., (Published by Elsevier B.V.)

The enantiomeric ratio of methylamphetamine (MAMP) is closely related to the optical activity of precursors and reagents used for the synthesis and this knowledge can provide useful information concerning the origins and synthetic methods used for illicit manufacture. The information can be utilized for regulation of the precursors and investigation of the manufacturing sources but this requires analytical procedures to determine purity of drug substances, impurity profiling and enantiomeric composition. In this study, a gas chromatography (GC) coupled with mass spectrometry (MS) method using a γ-cyclodextrin chiral stationary phase was developed and optimized for the simultaneous enantiomeric separations of MAMP and its common precursors, ephedrine, and pseudoephedrine, as well as its chlorointermediates formed during MAMP synthesis by the Emde method, after derivatization with trifluoroacetic anhydride. The optimization was performed using multivariate statistics (cluster analysis and principal components analysis) in order to select and compare optimal experimental conditions. Under the optimized experimental conditions, the calculated calibration curves showed good linearity range up to 0.1μg/mL for all tested analytes. The limits of detection were in the range of 0.002-0.008μg/mL and the coefficient of variability was between 1.0 and 3.9%. The method has the advantage of achieving excellent precision under repeatability and reproducibility conditions while detection by MS allows for the identity of analytes to be confirmed in a single analysis. The method was therefore applied satisfactory to MAMP analysis., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Alleviation of fatigue has been emerging as a serious issue that requires urgent attention. Health professionals and sports physiologists have been looking for active natural products and synthetic compounds to overcome fatigue in humans. This study was designed to define the anti-fatigue property of Rubus parvifolius L. (RPL) by characterization of active constituents using a mouse forced swimming test model. Four RPL fractions with different polarities containing anti-fatigue activity were sequentially isolated from the n-butanol RPL extract, followed by elution of 50% ethanol-water fraction from D101 macroporous resin chromatography to obtain nigaichigoside F1, suavissimoside R1 and coreanoside F1. Active constituents of the 50% ethanol-water eluate of RPL were total saponins. The fractions were examined based on the effect on weight-loaded swimming capacity of mice. Serum levels of urea nitrogen (SUN), triglyceride fatty acids (TG), lactate dehydrogenase (LDH), lactic acid (LA), ammonia and hepatic glycogen (HG) were also examined for potential mechanisms underlying the anti-fatigue effect of RPL extracts. During the experiment, two inflammatory markers, interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) in serum, were measured. We found that total saponins from RPL possess potent capabilities to alleviate mouse fatigue induced by forced swimming and that nigaichigoside F1 was responsible for the pharmacological effect. The underlying mechanisms include delays of SUN and LA accumulation, a decrease in TG level by increasing fat consumption, increases in HG and LDH so that lactic acid accumulation and ammonia in the muscle were reduced, and suppression of increased immune activation and inflammatory cytokine production. Our findings will be helpful for functional identification of novel anti-fatigue components from natural medicinal herbs.

Two new pentacyclic triterpenes named kirmanoic acid (1) and kurramanoic acid (2) have been isolated from the chloroform-soluble portion of the whole plant of Nepeta clarkei Hook. The structures of the two new compounds were assigned on the basis of their ¹H and ¹³C NMR spectra including two-dimensional NMR techniques such as COSY, HMQC, and HMBC experiments. Kirmanoic acid (1) was investigated for analgesic, anti-inflammatory, and CNS depressant activities. Interestingly kirmanoic acid (1) showed strong analgesic activity than standard drug in acetic induced writhing and formalin tests. Similarly kirmanoic acid (1) also showed strong anti-inflammatory activity than its standard drug. The gross behavioral study of kirmanoic acid (1) revealed that it exhibited mild CNS stimulant and muscle relaxant in the mice. Compound 1 showed a slight increase in Locomotor activity and possesses the antidepressant effect., (Copyright © 2012 Elsevier B.V. All rights reserved.)

CE methods with capacitively coupled contactless conductivity detection (C(4)D) were developed for the enantiomeric separation of the following stimulants: amphetamine (AP), methamphetamine (MA), ephedrine (EP), pseudoephedrine (PE), norephedrine (NE) and norpseudoephedrine (NPE). Acetic acid (pH 2.5 and 2.8) was found to be the optimal background electrolyte for the CE-C(4)D system. The chiral selectors, carboxymethyl-β-cyclodextrin (CMBCD), heptakis(2,6-di-O-methyl)-β-cyclodextrin (DMBCD) and chiral crown ether (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18C6H(4)), were investigated for their enantioseparation properties in the BGE. The use of either a single or a combination of two chiral selectors was chosen to obtain optimal condition of enantiomeric selectivity. Enantiomeric separation of AP and MA was achieved using the single chiral selector CMBCD and (hydroxypropyl)methyl cellulose (HPMC) as the modifier. A combination of the two chiral selectors, CMBCD and DMBCD and HPMC as the modifier, was required for enantiomeric separation of EP and PE. In addition, a combination of DMBCD and 18C6H(4) was successfully applied for the enantiomeric separation of NE and NPE. The detection limits of the enantiomers were found to be in the range of 2.3-5.7 μmol/L. Good precisions of migration time and peak area were obtained. The developed CE-C(4)D method was successfully applied to urine samples of athletes for the identification of enantiomers of the detected stimulants., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A selective capillary electrophoresis method using sulfobutyl ether-β-cyclodextrin as a chiral selector was developed and validated for the determination of the enantiomeric impurity of (R)-modafinil, i.e., armodafinil. Several parameters were optimized for a satisfactory enantioresolution, including the type and concentration of chiral selector and organic modifier, pH of background electrolyte (BGE), capillary temperature. The finally adopted condition was: 20 mmol/L phosphate buffer at pH 7.5, containing 20 mmol/L sulfobutyl ether-β-cyclodextrin and 20% methanol, at temperature of 25 °C. A good resolution of 3.3 for the two enantiomers of modafinil was achieved by applying the optimal conditions. The limit of detection (LOD) and limit of quantification (LOQ) of (S)-modafinil were 1.25 μg/mL and 2.50 μg/mL, respectively. The established method was also proven to display good selectivity, repeatability, linearity and accuracy. Finally, the method was used to investigate the enantiomeric purity of armodafinil in bulk samples.

Benzylpiperazine (BZP) is an amphetamine-type stimulant, which was legally available in New Zealand and widely used in "Party Pills" until reclassification as a Class C drug in April 2008. BZP was included as part of a multi-analyte method developed for hair screening using high-performance liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS). A 20-mg sample of hair is extracted and partially purified using mixed-mode solid-phase extraction cartridges prior to analysis by LC-MS/MS. The method was developed as a broad screen for drugs of abuse (including amphetamines, opiates, and benzodiazepines), with only the BZP results being presented here. The assay was validated and found to be linear over the range of 0.085 to 8.65 ng/mg with correlation coefficient of r (2) ≥ 0.99. Blank hair samples spiked with BZP at 0.22 and 2.16 ng/mg gave intra- and inter-day precision coefficients of variation of ≤10% (n = 6 per day, 3 days) at both levels and calculated extraction efficiencies of 78% and 91%, respectively. The results from the samples submitted to the laboratory for BZP analysis showed 11% were positive (n = 126). The mean BZP level was 3.9 ng/mg (range, 0.4-33 ng/mg; the result was extrapolated when above the calibration). These data are the first available showing the levels expected from users of BZP.

A confirmatory method for the determination of illicit drugs based on micro-solid phase extraction with modified tips, made of a functionalized fiberglass with apolar chains of octadecylsilane into monolithic structure, has been developed in this study. Drugs belonging to different chemical classes, such as amphetamine, methamphetamine, methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylenedioxymethylamphetamine, cocaine, benzoylecgonine, ketamine, mescaline, phencyclidine and psilocybine were analyzed. The quantitation was performed by liquid chromatography-tandem mass spectrometry and the analytes were detected in positive ionization by means of an electrospray source. The limits of quantification ranged between 0.3 ng mL(-1) for cocaine and 4.9 ng mL(-1) for psilocybine, with coefficients of determination (r(2)) >0.99 for all the analytes as recommended in the guidelines of Society of Forensic Toxicologists-American Association Forensic Sciences., (2010 Elsevier B.V. All rights reserved.)

CE with capacitively coupled contactless conductivity detection (C(4)D) was employed for the separation and detection of seven amphetamine analogues as well as amphetamine, dextroamphetamine, methamphetamine and 3,4-methylenedioxymethamphetamine. The separation electrolyte was 30 mM hydroxypropyl-beta-cyclodextrin (HPbetaCD) in a 75 mM acetic acid+25 mM sodium acetate buffer adjusted to pH 4.55. Conductivity detection was compared with UV detection using this same electrolyte. Average detection limits for C(4)D and UV were 1.3 and 1.0 ppm, respectively. The effects of HPbetaCD concentration and BGE composition on the selectivity of the separation were also investigated. An illicit, street-grade sample of 3,4-methylenedioxymethamphetamine (Ecstasy) and a prescription dextroamphetamine tablet were also analysed.

Seven mesocosm-scale constructed wetlands (CWs) of different configurations were operated outdoors for nine months to assess their ability to remove pharmaceuticals and personal care products (PPCPs) from urban wastewaters. CWs differed in some design parameters, namely the presence of plants, the species chosen (i.e., Typha angustifolia vs Phragmites australis), flow configuration (i.e., surface flow vs subsurface flow) and the presence of a gravel bed. A nearby conventional activated-sludge wastewater treatment plant (WWTP) fed with the same sewage was simultaneously monitored for comparison. The PPCPs ketoprofen, naproxen, ibuprofen, diclofenac, salicylic acid, carbamazepine, caffeine, galaxolide, tonalide and methyl dihydrojasmonate were monitored. The presence of plants favoured the removal of some PPCPs. The performance of the mesocosm studied was compound-dependant, soilless CWs showing the highest removal efficiency for ketoprofen, ibuprofen and carbamazepine, while free-water CWs with effluent leaving through the bottom of the tank performed well for the degradation of ketoprofen, salicylic acid, galaxolide and tonalide. Finally, subsurface horizontal flow CWs were efficient for the removal of caffeine. Significant linear correlations were observed between the removal of some PPCPs and temperature or redox potential. Hence, microbiological pathways appear to be the most probable degradation route for PPCPs in the CWs studied., (2010 Elsevier Ltd. All rights reserved.)

The efficiency of pencil lead fiber was investigated for effective head-space solid-phase microextraction (HS-SPME) of methamphetamine (MAMP) from aqueous standard solutions without chemical derivatization prior to gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. Most effective experimental parameters such as extraction temperature and time, sample pH, and salting out were studied and optimized. At the optimum conditions, the efficiency of this fiber was compared with polyacrylate (PA) commercial fiber, which is most selective for volatile and semi-volatile compounds. The results obtained prove the suitability of modified pencil-lead fiber for sampling of the studied compound from aqueous solutions. Under optimum conditions, the calibration plot was linear in the range of 40-8000 ng/mL (r = 0.998), and the detection limit was 27 ng/mL (n = 3). The proposed method was successfully applied for HS-SPME of MAMP from 200 microL human saliva, which has been spiked with trace amounts of MAMP (160 ng/mL) followed by GC-MS monitoring.

Heliopsis longipes S.F. Blake (Asteraceae: Heliantheae) (chilcuague) is used in Mexican traditional medicine against parasites and to alleviate tooth and muscle pains. Its biocide effect has already been experimentally demonstrated; however, its analgesic action and its action on the nervous system (NS) have not been investigated yet. The objectives of this study were to evaluate the analgesic action of affinin and the H. longipes root ethanol extract, as well as their effects on the NS using an animal model. The ethanol extract was obtained by maceration, and affinin was purified from it through chromatographic techniques. Chemical and thermal analgesia were used to assess their analgesic proprieties. Irwin's test was used to evaluate their stimulating or depressing effects. The ethanol extract and affinin displayed analgesic action similar to ketorolac and stimulating effect comparable to caffeine on the nervous system of adult mice.

The specific features of general anesthesia during short inpatient operations were performed in 85 patients who were regular CAT users owing to their national habits. According to the herbal psychogenic stimulant CAT dependence, the patients were divided into 3 groups. The findings indicate that propofol (2 mg/kg) in combination with isoflurane and premedication as diatepam (0.1-0.15 mg/kg) and fentanyl (1 mg/kg) is the anesthesia of choice in all group patients. Ketamine in combination with isoflurane may be used in the controls and Group 1 patients with mild CAT dependence. In patients with moderate and severe CAT dependence, ketamine should be considered to be contraindicated due to the development of adverse psychomotor and somatic reactions requiring monitoring and drug correction in an intensive care unit. The results of the study have been introduced into practice on choosing the modes of anesthesia at the Revolution Hospital, Republic of Yemen.

Varieties of kola nuts (Cola nitida alba, Cola nitida rubra A. Chev, and Cola acuminata Schott & Endl), a group of popular Nigerian and West African stimulants, were analyzed for their content of secondary plant metabolites. The three varieties of the kola nuts contained appreciable levels of (+)-catechin (27-37 g/kg), caffeine (18-24 g/kg), (-)-epicatechin (20-21 g/kg), procyanidin B 1 [epicatechin-(4beta-->8)-catechin] (15-19 g/kg), and procyanidin B2 [epicatechin-(4beta-->8)-epicatechin] (7-10 g/kg). Antioxidant capacity of the extracts and purified metabolites was assessed by two HPLC-based and two colorimetric in vitro assays. Extracts of all varieties exhibited antioxidant capacity with IC 50 values in the range 1.70-2.83 and 2.74-4.08 mg/mL in the hypoxanthine/xanthine oxidase and 2-deoxyguanosine HPLC-based assays, respectively. Utilization of HPLC-based assays designed to reflect in situ generation of free radicals (e.g., HO(*)), as opposed to general assays (DPPH, FRAP) in common use which do not, indicate that, of the major secondary plant metabolites present in kola nut extracts, caffeine is potentially the more effective cancer chemopreventive metabolite in terms of its antioxidant capacity.

We studied the effects of tutin, a sesquiterpenoid obtained from Coriaria ruscifolia subspecie ruscifolia, a native poisonous Chilean plant, on spinal glycine receptors using patch clamp recordings. In addition, cytosolic Ca(2+) transients and activation of cAMP response element-binding protein (CREB) were measured in the presence of tutin. Application of tutin (1-1000 microM) inhibited the glycinergic evoked current in a concentration-dependent manner. Moreover, the frequency of spontaneous Ca(2+) spikes and spontaneous synaptic activity (AMPAergic events) was augmented and correlated with an increase in phosphorylated CREB levels, suggesting an enhancement in neuronal excitability. These results may explain the toxic effects of the plant characterized by seizures and convulsions with subsequent coma and death seen in humans and mice.

With the increasing number of abused stimulant and psychedelic drugs, along with so called "dance drugs" and "new synthetic drugs" available on the Czech illegal market, there is a need to update methods in toxicological laboratories and therefore it is necessary to develop and optimalize screening and identification procedures for new toxic substances appearing in the laboratory practice. It is well known that relatively popular commercial screening immunoassays have some limits: for instance restricted amount of detectable substances, specificity and sensitivity of detection. Therefore, it is mandatory to combine or complete them with more specific methods based on a different principle. In this paper we have focused on collecting useful analytical data to introduce or complete the system of detection and identification of unknown drugs and their metabolites which can appear in biological samples by using gas chromatography-mass spectrometry (GC-MS) after preparation of relevant acetylated derivatives. The collection of experimental data involves retention indexes and mass spectra of acetylated phenylalkylamines, tryptamines and piperazines and some of their metabolites. These data are fundamental for laboratory diagnostics of drugs of abuse or intoxication and they can be useful for practical application in a number of toxicological laboratories. The mean limit of detection 0.1 ng analyte injected to GC-MS is low enough to allow the method to be successfully applied to real toxicological samples.

In a preliminary study pyroglutamate showed to be over 10 times increased in some lyophilised coffees with respect to brewed or filtered coffees, and probably that increase is related to some stage of the industrial process. Pyroglutamate is known to have a number of remarkable cognitive enhancing effects, which could be also related to the properties of coffee traditionally associated to caffeine. Pyroglutamate improves memory and learning and has anti-anxiety effects in rats. Therefore, a method has been developed and validated for the simultaneous determination of caffeine and pyroglutamate in coffee by capillary electrophoresis. Separation conditions employed MECK conditions with 50 mM borate buffer at pH 9.5 with 130 mM SDS. The applied potential was 10 kV and detection was performed at 200 nm. Afterwards, 10 soluble coffees from the market were measured and caffeine and pyroglutamate levels were compared. Those coffees with higher pyroglutamate with or without caffeine were preliminarily tested for sedative/stimulant properties and cognition enhancing effects in mice. The most relevant finding was a partial reversal of scopolamine-induced amnesia in the passive avoidance paradigm after oral administration of one coffee.

An easy, rapid method for simultaneous determination of strychnine and brucine in Strychnos nux-vomica L. and its preparation was developed by nonaqueous capillary electrophoresis (NACE) without pretreatment for the first time. Optimum separation was achieved with a fused-silica capillary column (50 cmx75 microm i.d.) and a running buffer containing 30 mM ammonium acetate, 1.0% acetic acid and 15% acetonitrile (ACN) in methanol medium. The applied voltage was 30.0 kV. The analytes were detected by UV at 214 nm. The effects of concentration of ammonium acetate, acetic acid and organic modifier on electrophoretic behavior of the analytes were studied. The established method with sophoridine as internal standard was linear in the range of 5-1000 mg/mL for both strychnine and brucine. The extracts of Strychnos nux-vomica and its preparation could be directly injected for determination with recoveries ranging from 94.5 to 104%.

High-performance liquid chromatography (HPLC) separation of drugs at elevated pressure with 1.7 microm hybrid C18 stationary phase columns was investigated. This technique, which uses instrumentation engineered to handle the narrow peaks and high back pressures generated by 1.7 microm particle columns, provided significantly better resolution and/or faster analysis than conventional HPLC and capillary electrophoresis (CE). The use of 2mm internal diameter (i.d.) columns of 3-10 cm length has been evaluated for the separation of basic and neutral drugs, drug profiling, and general screening (including acidic drugs). For these applications, compared to conventional HPLC and CE, it provided up to 12x and 3x faster analyses, respectively. Precision was excellent for both isocratic and gradient analyses. For retention time and peak area, RSDs of < or =0.1% were obtainable. Fifteen anabolic steroids and esters were well separated in a 2.5 min gradient. For drug profiling, compared to HPLC and CE, approximately twice as many peaks were resolved. HPLC at elevated pressure is also well suited as a general screening technique. Twenty-four solutes of varying drug classes including narcotic analgesics, stimulants, depressants, hallucinogens, and anabolic steroids were fully separated in a 13.5 min gradient.

(-)-Ephedrine (EP) and (+)-Pseudoephedrine (PEP) in Jiketing granule were separated by TLC, RP-HPLC, GC, HPLC-MS, and the chromatographic phenomenon was interpreted by the topological indices. The observed chromatographic separations of investigated components were compared. This comparison indicated that simply methods as C18 RP-HPLC and GC are the more effective techniques, and more suitable than others for this preparation, for the separation of two alkaloids.

The literature from 1990 to 2003 on the relation between coffee, decaffeinated coffee, tea and colorectal cancer risk has been reviewed. For the relation with coffee, three cohort (517 total cases) and nine case-control studies (7555 cases) analysed colon cancer; three cohort (307 cases) and four case-control studies (2704 cases) rectal cancer; six case-control studies (854 cases) colorectal cancer. For colon cancer most case-control studies found risk estimates below unity; the results are less clear for cohort studies. No relation emerged for rectal cancer. A meta-analysis, including five cohort and twelve case-control studies, reported a pooled relative risk of 0.76 (significant). Any methodological artefact is unlikely to account for the consistent inverse association in different countries and settings. Plausible biological explanations include coffee-related reductions of cholesterol, bile acids and neutral sterol secretion in the colon; antimutagenic properties of selected coffee components; increased colonic motility. Decaffeinated coffee was not related to either colon or rectal cancer in three case-control studies. No overall association between tea and either colon or rectal cancer risk emerged in seven cohort (1756 total cases of colon, 759 of rectal and 60 of colorectal cancer) and 12 case-control studies (8058 cases of colon, 4865 of rectal, 604 of colorectal cancer).

A brownwater sample with a high content of humic substances (HS) was fractionated by multistage ultrafiltration (mst-UF) into five fractions with nominal molecular weights ranging from >30 to <1 kDa. Fractions were characterized with respect to molecular size distribution and structure. Size exclusion chromatography with online DOC detection revealed that mst-UF yielded fractions with decreasing Mp (molecular weight at peak maximum) and polydispersities from nominally large to small mst-UF fractions. 13C MAS NMR analysis showed that the content of carbohydrate structures decreased from the original sample toward smaller molecular weight (MW) fractions, which in turn contained more carboxylic groups and branched aliphatic structures. Specific UV absorbances (SUVA254) were highest in the >30 kDa fraction and decreased with decreasing MW. To evaluate whether separation mechanisms other than size exclusion were of importance during the fractionation, the behavior of low molecular weight model compounds (MC) with a range of polarities was studied. Recoveries decreased with increasing hydrophobicity of the MC. For selected nonylphenol ethoxylates and 4-nonylphenol the recovery correlated well with the hydrophile-lipophile balance value. The presence of dissolved organic matter (DOM) caused an additional loss of hydrophobic MC, possibly because of sorption of the compounds onto DOM fouling layers. The hydrophilic MC caffeine was recovered almost completely (85-86%) regardless of the DOM content of the model solution. It was concluded that size exclusion was the dominant fractionation mechanism for caffeine, whereas hydrophobic interactions played a major role during the mst-UF fractionation of nonpolar contaminants. For a better understanding of the behavior of polyfunctional molecules such as HS, the effect of other physicochemical properties needs to be investigated in further studies.

Due to their high polarity and low vapor pressure, most amine salts of amphetamine-type drugs are not directly amenable to headspace recovery using solid-phase microextraction (SPME). Described in this article is a simple vapor-phase procedure for the conversion of solid drug salt samples into their free bases by the use of triethylamine. This process can be conducted simultaneously with headspace SPME, the outcome being that solid drug salts can be sampled directly for GC-MS without the need for dissolution and chemical processing. Potential applications for this methodology include the noninvasive recovery of drug traces from objects such as banknotes and garments. This new process for recovery of amphetamine-type drugs has been combined with on-fiber derivatization using alkylchloroformates. This extra step was included to improve the chromatographic performance of analytes and allow for the resolution of drug enantiomers.

The chiral separation of (+/-)-methamphetamine, (+/-)-methcathinone, (+/-)-ephedrine and (+/-)-pseudoephedrine by means of beta-cyclodextrine modified capillary electrophoresis is described. The distribution of enantiomers in clandestine tablets and urine samples were identified. Several electrophoretic parameters such as the concentration of beta-cyclodextrin, temperature, the applied voltage and the amount of organic solvent required for successful separation were optimized. The method, as described herein, represents a good complementary method to GC-MS for use in forensic and clinical analysis.

This review article draws the attention to the many species of plants possessing activity on the central nervous system (CNS). In fact, they cover the whole spectrum of central activity such as psychoanaleptic, psycholeptic and psychodysleptic effects, and several of these plants are currently used in therapeutics to treat human ailments. Among the psychoanaleptic (stimulant) plants, those utilized by human beings to reduce body weight [Ephedra spp. (Ma Huang), Paullinia spp. (guaraná), Catha edulis Forssk. (khat)] and plants used to improve general health conditions (plant adaptogens) were scrutinized. Many species of hallucinogenic (psychodysleptic) plants are used by humans throughout the world to achieve states of mind distortions; among those, a few have been used for therapeutic purposes, such as Cannabis sativa L., Tabernanthe iboga Baill. and the mixture of Psychotria viridis Ruiz and Pav. and Banisteriopsis caapi (Spruce ex Griseb.) C.V. Morton. Plants showing central psycholeptic activities, such as analgesic or anxiolytic actions (Passiflora incarnata L., Valeriana spp. and Piper methysticum G. Forst.), were also analysed.Finally, the use of crude or semipurified extracts of such plants instead of the active substances seemingly responsible for their therapeutic effect is discussed.

We investigated the simultaneous chiral separation of nine amphetamine type stimulants (dl-norephedrine, dl-norpseudoephedrine, dl-ephedrine, dl-pseudoephedrine, dl-amphetamine, dl-methamphetamine, dl-methylenedioxyamphetamine (MDA), dl-methylenedioxymethamphetamine (MDMA), and dl-methylenedioxyethylamphetamine (MDEA)) by capillary electrophoresis using highly sulfated gamma-cyclodextrin (SU(XIII)-gamma-CD) as a chiral selector. Three different approaches using SU(XIII)-gamma-CD with 50 mM phosphate background electrolyte were designed; (I) high CD concentration (10 mM SU(XIII)-gamma-CD) at neutral pH (pH 7.0) in the normal polarity mode, (II) low CD concentration (1.0 mM) at low pH (pH 2.6) in the normal polarity mode and (III) high CD concentration at low pH (pH 2.6) in the reversed-polarity mode. In mode (II), the effects of adding three neutral CDs (beta-CD, dimethyl-beta-CD and hydroxypropyl-beta-CD) were also investigated. The best separation was obtained after optimizing mode (III) as follows: run buffer of 10 mM SU(XIII)-gamma-CD with 50 mM phosphate background electrolyte at pH 2.6, applied voltage of -12 kV and capillary temperature of 15 degrees C.

A simple and highly sensitive method for analysis of derivatized methamphetamine (MA) and amphetamine (AM) in whole blood was developed using headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry electron impact ionization selected ion monitoring (GC-MS-EI-SIM). A whole blood sample, deuterated-MA (d(5)-MA), as an internal standard (IS), tri-n-propylamine and pentafluorobenzyl bromide were placed in a vial. The vial was heated and stirred at 90 degrees C for 30min. Then the extraction fiber of the SPME was exposed at 90 degrees C for 30min in the headspace of the vial while being stirred. The derivatives adsorbed on the fiber were desorbed by exposing the fiber in the injection port of a GC-MS. The calibration curves showed linearity in the range of 0.5-1000ng/g for both MA and AM. The time for analysis was about 80min per sample. In addition, this proposed method was applied to two autopsy cases where MA ingestion was suspected. In one case, MA and AM concentrations in the mixed left and right heart blood were 165 and 36.9ng/g, respectively. In the other case, MA and AM concentrations were 1.79 and 0.119 microg/g in the left heart blood, and 1.27 and 0.074 microg/g in the right heart blood, respectively.

Alkaloids extracted from the green tea were separated by high-speed counter-current chromatography. A series of experiments have been performed to investigate effects of different solvent system. A system of CHCl3-CH3OH-NaH2PO4(23 mmol/L) = (4:3:2) was selected, in which the upper phase was used as the stationary phase, and the lower phase as mobile phase. When acidity of solvent system is pH 5.6, three chemical components are very efficiently isolated by one injection of 50 mg sample mixture. Analyzing the eluted fractions by TLC, we know that one is caffeine, and the other is theophylline. In comparing the separation results by high-speed counter-current chromatography with those by TLC, the advantages of this method is verified. It should find wide applications of this technology for the separation of crude mixture of plant components.