Fabric analysis by ambient mass spectrometry for explosives and drugs
ABSTRACT Desorption electrospray ionization (DESI) is applied to the rapid, in-situ, direct qualitative and quantitative analysis of mixtures of explosives and drugs from a variety of fabrics, including cotton, silk, denim, polyester, rayon, spandex, leather and their blends. The compounds analyzed were explosives: trinitrohexahydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN) and the drugs of abuse: heroin, cocaine, and methamphetamine. Limits of detection are in the picogram range. DESI analyses were performed without sample preparation and carried out in the presence of common interfering chemical matrices, such as insect repellant, urine, and topical lotions. Spatial and depth profiling was investigated to examine the depth of penetration and lateral resolution. DESI was also used to examine cotton transfer swabs used for travel security sample collection in the screening process. High throughput quantitative analysis of fabric surfaces for targeted analytes is also reported.
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- "Ambient MS methods have the potential to drastically simplify preliminary analyses by eliminating the need for sample preparations , while bolstering the information content by providing mass spectral data without requiring lengthy chromatography steps.        In this capacity, the rapidity of the test along with the high mass accuracy of the time-of-flight (TOF) analyzer would serve in a complementary fashion to traditional confirmatory GC- MS methods, which generally only provide integer mass information . Ambient methods combined with high accuracy instruments have demonstrated the potential to enhance analysis in sports doping, particularly in regards to emerging drugs. "
ABSTRACT: Dimethylamylamine (DMAA) is a sympathomimetic amine found in weight-loss/workout supplements or used as an appetite suppressant. DMAA is a stimulant that is banned by the World Anti-Doping Agency (WADA). Adverse health effects as well as fatalities have been implicated with its use. Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization method that was employed to rapidly identify the presence of DMAA in various samples without any extraction or preparations whatsoever. DMAA was first identified in supplements, sampled directly in their solid forms. Furthermore, DMAA was detected directly in urine over 48 h as a means of indicating recent abuse of the substance. DART-MS analysis is instantaneous, and coupled with the high mass accuracy associated with the time-of-flight mass analyzer, results in unequivocal identification of the presence of DMAA. These features demonstrate DART-MS as an attractive potential alternative screening method for the presence of drugs and medications or for toxicological investigations. Copyright © 2013 John Wiley & Sons, Ltd.Drug Testing and Analysis 07/2014; 6(7-8). DOI:10.1002/dta.1540 · 2.82 Impact Factor
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ABSTRACT: The behaviour of a 7.5 kW high efficiency cage induction motor fed by distorted supply has been investigated in this paper. Experimental data were collected by developing a testing facility consisting of a three phase harmonic generator, a double chamber calorimeter and a PC based data acquisition system. Motor additional losses due to the presence of harmonics were estimated using the calorimetric method. It has been shown that a distorted voltage containing low order harmonics causes more losses in the motor as compared with the high order harmonics. Accordingly, weighted THD (WTHD) has been defined to specify the limits for additional losses in a motor supplied by distorted voltages. The variation of test motor parameters with harmonic order as well as the variation of additional losses with WTHD has led to establishment of derating factor (DF) for the test induction motor. Applicability of the DF on several induction motors with different power ratings has been examined. It has been demonstrated that with a service factor of 1.15, most induction motors are capable to handle distorted voltages as defined by standardsElectrical and Computer Engineering, 2000 Canadian Conference on; 02/2000
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ABSTRACT: The purpose of the work presented here is to characterise polymeric HVDC cable insulation consisting of lapped thin film polypropylene with respect to DC current conduction and partial discharge activity in air filled butt gaps. The PD activity was found to strongly increase with increasing temperature and applied electric stress. The discharge frequency decreased with time after voltage application and the effect of the void size was found to be of minor importance. These observations agree very well with the proposed theory stating that the discharge frequency will be proportional to the current flowing through the insulationSolid Dielectrics, 2001. ICSD '01. Proceedings of the 2001 IEEE 7th International Conference on; 02/2001