1,721,036 research outputs found
HAIR ANALYSIS FOR DRUGS OF ABUSE AS A LABORATORY TOOL IN REGRANTING OF DRIVING LICENCES: A PRELIMINARY STUDY
No full text14TH INTERNATIONAL CONFERENCE ON ALCOHOL, DRUGS AND TRAFFIC SAFETY - ANNECY (FRANCE
Synthesis and characterization of ethyl sulfate and D-5-ethyl sulfate as reference substances for applications in clinical and forensic toxicology
No full text
Full-Aeroelastic Model of CAARC Building: Iterative Design Procedure and Wind Tunnel Tests
No full textA first step of a broader framework, concerning the investigation of tall buildings’ dynamic response to wind load, is presented. In order to accomplish this challenging task, a well-known benchmark has been selected: the CAARC (Commonwealth Advisory Aeronautical Research Council) standard tall building. Decades of literatures on the subject make it the perfect candidate to tackle the complexity of wind-structure interaction phenomena. The present work concerns the design of a full-aeroelastic multi degrees of freedom model. The configuration proposed by J. Holmes at International Conference on Wind Engineering (2007), accounting for both flexural and torsional decoupled modes of vibrations, is adopted. A design theory present in literature is re-proposed, from a different prospective, in a semi-automated fashion through a Python script. At last, preliminary results are shown, demonstrating the method’s efficiency and applicability, not only to tall buildings, but more generally to structures with continuous distribution of mass
HFBB model test for tall buildings: A comparative benchmark with a full-aeroelastic model
No full textA novel approach to full-aeroelastic model design is presented, considering continuous structures and coupled modes. Its validity is proven by building a full-aeroelastic CAARC standard tall building model featuring 12-degrees-of-freedom at 1:360 scale. A complete description of its design, manufacturing, tuning, and dynamic identification is reported. The model is tested in a novel wind-tunnel experimental campaign performed at the CRIACIV facility (Prato, Italy). A comparative study of aerodynamic and full-aeroelastic response in terms of base moment and accelerations shows that the aerodynamic model tends to overpredict the response along the broader side of the model. The contribution of second modes is found to be relevant for induced acceleration at the rooftop
Highly specific quantification of ergotamine in urine, blood, and hair samples by liquid chromatography-tandem mass spectrometry
No full textErgotamine has been used for therapeutic purposes since the 1950s, usually to treat vascular headache. It is highly toxic and in large, repeated doses can produce all the symptoms of ergot poisoning. A selective and sensitive method, based on liquid chromatography-tandem mass spectrometry (LC-MS2), has been developed for quantifying ergotamine in biological fluids with use of a quick and easy sample preparation. Ergotamine and the internal standard, trideuterated lysergic acid diethylamide, were extracted from human urine, blood, and hair by means of liquid-liquid extraction at alkaline pH. Gradient elution on a cyanopropyl column was used for chromatographic separation. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method was validated and successfully applied to a case of iatrogenic ergotism resulting from the intake of ergotamine tartrate for treating headache. For the first time, ergotamine was identified and quantified in hair. The ergotamine concentrations measured were 320 pg/mL in blood, 100 pg/mL in urine, 24 pg/mg in proximal hair, and 15 pg/mg in distal hair
QUALITY CONTROL IN TOXICOLOGICAL ANALYSIS
No full textThe validity and effectiveness of quality control procedures are reviewed here in light of the principles of analytical toxicology, and of the professional responsibility involved in awareness of the profound influence which analytical results have in the fields of health and social security. Regardless of the methods used, laboratory work should aim essentially at achieving a very high degree of reliability. Factors contributing to the 'quality' of analytical results and methods used to check their reliability are discussed here. The technical background and organization of internal and external quality control procedures are presented, with particular reference to educational aspects, and to the ways in which computer and internet technologies may be exploited for further improvement of the effectiveness of these procedures
Simultaneous identification of amphetamine and its derivatives in urine using HPLC-UV.
No full textAn HPLC-LV method for the simultaneous identification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) in urine is described. It includes a rapid extraction procedure of the 4 analogs from urine using Extrelut 3 columns, derivatization with sodium 1,2-naphthoquinone-4-sulphonate (NQS) to obtain highly chromophoric UV-VIS derivatives, and a final HPLC analysis using an ion-pair reversed-phase technique with eluent monitoring at 480 nm. Structural characterization of the derivatives obtained by mass spectrometry is reported. Recoveries of the amphetamines were in the range 80-85% at concentrations of 300 ng/ml. Practical detection limits were 40-60 ng/ml (S/N ratio = 10) for al derivatives. The chromatographic peaks for the NQS derivatized amphetamines are fairly narrow and well resolved. The method is simple, rapid, quite sensitive, and specific for convenient confirmation of preliminary positive results obtained with immunoassays
An improved method for cyanide determination in blood using solid-phase microextraction and gas chromatography/mass spectrometry
No full textA new method is described for the qualitative and quantitative analysis of cyanide, a very short-acting and powerful toxic agent, in human whole blood. It involves the conversion of cyanide into hydrogen cyanide and its subsequent headspace solid-phase microextraction (HS-SPME) and detection by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. Optimizing the conditions for the GC/MS (type of column, injection conditions, temperature program) and SPME (choice of SPME fiber, effect of salts, adsorption and desorption times, adsorption temperature) led to the choice of a 75-mu m carboxen/polydimethylsiloxane SPME fiber, with D-3-acetonitrile as internal standard, and a capillary GC column with a polar stationary phase. Method validation was carried out in terms of linearity, precision and accuracy in both aqueous solutions and blood. The limit of detection (LOD) and limit of quantitation (LOQ) were determined only in aqueous solutions. The assay is linear over three orders of magnitude (water 0.01-10, blood 0.05-10 mu g/mL); and the LOD and LOQ in water were 0.006 and 0.01 mu g/mL, respectively. Good intra- and inter-assay precision was obtained, always < 8%. The method is simple, fast and sensitive enough for the rapid diagnosis of cyanide intoxication in clinical and forensic toxicology
DETERMINATION OF MIDAZOLAM IN HUMAN PLASMA BY SOLID-PHASE MICROEXTRACTION AND GAS-CHROMATOGRAPHY/MASS SPECTROMETRY
No full textA new method is described for the qualitative and quantitative analysis of midazolam, a short-acting 1,4-imidazole benzodiazepine, in human plasma. It involves a plasma deproteinization step, solid-phase microextraction (SPME) of midazolam using an 85-microm polyacrylate fiber, and its detection by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode, using pinazepam as internal standard. The assay is linear over a midazolam plasma range of 1.5-300 ng/mL, relative intra- and inter-assay standard deviations at 5 ng/mL are below 7%, and the limit of detection is 1 ng/mL. The method is simple, fast and sufficiently sensitive to be applied in clinical and forensic toxicology as well as for purposes of therapeutic drug monitoring
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