Detection Of Narcotics Research Articles

The Need to Carefully Interpret the Statistics Reporting the Accuracy of a Narcotics Detection Dog: Application to South Dakota v. Nguyen, State of Florida v. Harris and Similar Cases

The Need to Carefully Interpret the Statistics Reporting the Accuracy of a Narcotics Detection Dog: Application to South Dakota v. Nguyen, State of Florida v. Harris and Similar Cases

Modeling-based optimization study for an EDXRD system in a portable configuration

Abstract Energy-Dispersive X-ray Diffraction (EDXRD) is well suited for the detection of narcotics and a wide range of explosives. This technique, combined with the dual-energy tomosynthesis, has been used for verification of a novel portable imaging system, the aim of which is characterization of dangerous/illicit materials inside objects. We present the design methodology and optimization study using EDXRD modality. In order to evaluate the experimental conditions best suited for system purposes, kinematic theory of diffraction has been exploited to model the height and shape of diffraction patterns. From the simulation-based analysis a diffraction angle of 2.75°±0.10° and an X-ray tube voltage ≤160 kV have been selected.

Evaluation of extractive electrospray ionization and atmospheric pressure chemical ionization for the detection of narcotics in breath

Diagnosis by online breath analysis using mass spectrometry is challenging because of the low concentrations of pertinent compounds in breath. Here we investigate extractive electrospray ionization and atmospheric pressure chemical ionization for the detection of narcotics in breath. The limit of detection was evaluated for morphine, fentanyl, norfentanyl, naloxone, cocaine, γ-hydroxybutyrolactone (GBL), and nicotine. They were found to be in the low fmol/s range, depending on the ionization system used. Data was obtained on four different mass spectrometers: A quadrupole time-of-fight instrument, a 3D ion trap, a linear ion trap, and a portable ion trap. A system was developed to mix reference compounds with breath for the investigation of the ionization sources as well as for standardization and online quantification of semi-volatile compounds in breath.

Direct Detection of Heroin Metabolites Using a Competitive Immunoassay Based on a Carbon‐Nanotube Liquid‐Gated Field‐Effect Transistor

A carbon-nanotube-based liquid-gated field-effect transistor is employed for the detection of heroin narcotics. Detection of monoacetylmorphine down to 15 pg mL−1 is accomplished by means of a competitive immunoassay protocol in conjunction with charged Au nanoparticles that augment the electrostatic perturbance generated from the receptor–ligand interaction coupled with the carbon nanotubes.

SVD for enhanced explosives detection using NQR

Nuclear Quadrupole Resonance (NQR) is a solid-state radio frequency (RF) spectroscopic technique, allowing the detection of many high explosives and narcotics. Unlike metal detectors and ground penetrating radar (GPR), NQR detectors measure signals that are unique to the explosives, thus can provide a lower false alarm rate. The practical use of NQR is restricted by the inherently low signal-to-noise ratio (SNR) of the observed signals, a problem that is further exacerbated by the presence of strong RF interference (RFI), so a robust detection method is required. Singular value decomposition (SVD) based on Hankel matrix is proposed to detect the NQR signal in this paper. The original signal can be decomposed into the linear superposition of a series of component signals by SVD using Hankel matrix, and the process of constructing the Hankel matrix shows that a component T signal can be produced by averaging the elements on the inverse diagonal of the Ai=σiuiviT. Then an eigendecomposition based spectrum estimator called “Multiple Signal Characterization” (MUSIC) is applied to estimate power spectrum of each component signal, so the RFI and the noise are canceled by using the priori knowledge of the NQR frequency. Finally, an average power detector is applied to detect NQR signal. The result using measured data shows that the proposed method can provide robust NQR detection performance.

Early scent association for the working canine: Creating a narcotics detection canine for the average canine handler

s 239 play with, and retrieve toys. At 3, 6, 9, and 12 months of age, each dog is rated on 4 traits: the speed and desire to chase and pick up a thrown odor-saturated object (Chase Retrieve, CR); persistence in playing tug-of-war with the object (Physical Possession, PP); the length of time the dog keeps the object (Independent Possession, IP); and the ability to focus on a handler hiding the object (Mental Possession, MP). To evaluate the possibility of improving these traits through genetic selection, heritabilities (and standard errors) were estimated for each trait: CR, 0.16 (0.042); PP 0.36 (0.045); IP 0.37 (0.044); and MP 0.26 (0.047). These significant heritabilities suggest these traits could be improved by selective breeding in future generations.

Detox agents do not affect the pharmacokinetics of methamphetamine in the rat

Recently, ‘detox’ agents have been popularly used as forms of diets or nutritional supplements. Especially, several cases have been reported that these detox agents have been used to mask drug tests among drug abusers. In the present study, capsule and drink types of detox agents were evaluated for their ability to alter the elimination of methamphetamine (MA) in rats. For this study, MA and its major metabolite, amphetamine (AP) in urine samples were determined using LC–tandem mass spectrometry after administration of the detox agents to MA-treated rats. As a result, significant differences were not shown between control and detox-dosed groups in the amounts of MA and AP excreted into urine as well as the volume of excreted urine. This result suggests that the detox agents tested may not affect the metabolism or elimination of MA and further might have minimal effect on narcotics detection in the urine samples of drug abusers.

Countering Radio Frequency Interference in Single-Sensor Quadrupole Resonance

Nuclear quadrupole resonance (NQR) is a solid-state radio frequency (RF) spectroscopic technique that allows for the detection of many narcotics and highly explosive substances. Unfortunately, the practical use of NQR is often restricted by the presence of strong RF interference (RFI). In this letter, extending our recent work on stochastic NQR (sNQR), we propose acquiring signal-of-interest free samples, containing only corrupting signals, and exploiting them to reduce the effects of RFI on conventional NQR (cNQR) measurements. Similar to the sNQR case, the presented detectors are able to substantially outperform previous cNQR detectors when RFI is present.

Principles and applications of compact laser–plasma accelerators

Rapid progress in the development of high-intensity laser systems has extended our ability to study light–matter interactions far into the relativistic domain, in which electrons are driven to velocities close to the speed of light. As well as being of fundamental interest in their own right, these interactions enable the generation of high-energy particle beams that are short, bright and have good spatial quality. Along with steady improvements in the size, cost and repetition rate of high-intensity lasers, the unique characteristics of laser-driven particle beams are expected to be useful for a wide range of contexts, including proton therapy for the treatment of cancers, materials characterization, radiation-driven chemistry, border security through the detection of explosives, narcotics and other dangerous substances, and of course high-energy particle physics. Here, we review progress that has been made towards realizing such possibilities and the principles that underlie them.

A microarray chip for label-free detection of narcotics

A protein array chip for label-free optical detection of low molecular weight compounds has been developed. As a proof of principle, the chip is proven capable of rapidly (approximately 1 min) determining hits from aqueous cocktails composed of four common narcotics, cocaine, ecstasy, heroin, and amphetamine, using imaging surface plasmon resonance (SPR) as the detection principle. The chip is produced by injecting a mixture of antibodies and letting them self-sort and bind to narcotic analog coupled proteins already present in a predefined pattern on the supporting substrate. An indirect detection method, where antibodies are displaced from the surface upon recognition of their corresponding narcotics, is used to obtain the optical contrast and thus a detectable SPR and/or ellipsometric signal. Two types of readouts are possible from the present setup: intensity SPR images and SPR/ellipsometric sensorgrams. Positive hits were routinely obtained for analyte concentrations of 50 pg/microL and the limit of detection, without any parameter optimizations, seems to fall in the range 0.5 pg/microL (1.4 nM) for heroin, 2.5 pg/microL (8.2 nM) for cocaine, and 5 pg/microL for the other two narcotics (26 nM for ecstasy and 37 nM for amphetamine). With improved readout possibilities (sampling frequency), signal evaluation algorithms, and antibody-antigen design strategies, we believe this limit can be further improved. The chip is shown to work for many measurement cycles with excellent reproducibility. Moreover, with a more advanced fluidic system, excess injected antibodies could be collected and reused for many cycles, which could make the running costs of the system very low. The chip is in no way limited to detection of narcotics. Other low molecular weight compounds could easily be detected on the same chip. For example, trinitrotoluene detection has already been demonstrated using our chip. Possible areas of application for the system are therefore envisaged in airport and underground transport security, customs, drug interdiction, forensics, and as warning alerts on military equipment and personnel.

Pressure‐assisted capillary electrochromatography with electrospray ionization‐mass spectrometry based on silica‐based monolithic column for rapid analysis of narcotics

A pressure-assisted CEC (pCEC) with ESI-MS based on silica-based monolithic column was developed for rapid analysis of narcotics. Combining the extremely high permeability and separation efficiency of silica-based monolithic column with the high selectivity and sensitivity of pCEC-ESI-MS, the developed system exhibited its prominent advantages in separation and detection. A systematic investigation of the pCEC separation and ESI-MS detection parameters was performed. Experiment results showed that the optimized separation efficiency could be obtained at 8 bar assisted pressure with 25 kV separation voltage, using the solution containing 65% ACN v/v and 20 mmol/L ammonium acetate with pH 6.0 as running buffer. 3 microL/min of sheath liquid was considered as the optimized flow rate since it could provide the maximum signal intensity. Under the optimum conditions, the tested five narcotics could be completely separated within 10 min with the detection limit in the range of 2.0-80 nmol/L. The proposed method has been successfully used for detection of narcotics in real urine samples.

Development of a qualitative liquid chromatography/tandem mass spectrometric method for the detection of narcotics in urine relevant to doping analysis

A new screening procedure for 18 narcotics in urine for anti-doping purposes has been developed using liquid chromatography/triple quadrupole mass spectrometry (LC/MS). Electrospray ionization (ESI) was used as interface. Infusion experiments were performed for all substances to investigate their mass spectrometric behaviour in terms of selecting product specific ions. These product ions were then used to develop a tandem mass spectrometric method using selected reaction monitoring (SRM). For the LC/MS analysis, chromatography was performed on an octadecylsilane column. The total run time of the chromatographic method was 5.5 min. For the sample preparation prior to LC/MS analysis, the urine samples were liquid-liquid extracted at pH 9.5 after overnight enzymatic hydrolysis. Two extraction solvents were evaluated: dichloromethane/methanol 9/1 (v/v), which is currently used for the extraction of narcotics, and diethyl ether, used for the extraction of steroids. With diethyl ether the detection limits for all compounds ranged between 0.5 and 20 ng/mL and with the mixture containing dichloromethane the detection limits ranged between 0.5 and 10 ng/mL. Taking into account the minimum required performance limits of the World Anti-Doping Agency of 200 ng/mL for narcotics, diethyl ether can also be considered as extraction solvent for narcotics. Finally, the described method was applied to the analysis of urine samples previously found to contain narcotics by our routine gas chromatography/mass spectrometry (GC/MS) method.

Comprehensive screening method for the qualitative detection of narcotics and stimulants using single step derivatisation

A selective and sensitive screening method for the detection of prohibited narcotic and stimulating agents in doping control is described and validated. This method is suitable for the detection of all narcotic agents mentioned on the World Anti-Doping Agency (WADA) doping list in addition to numerous stimulants. The analytes are extracted from urine by a combined extraction procedure using CH 2Cl 2/MeOH (9/1, v/v) and t-butylmethyl ether as extraction solvents at pH 9.5 and 14, respectively. Prior to GC–MS analysis the obtained residues are combined and derivatised with MSTFA. The mass spectrometer is operated in the full scan mode in the range between m/ z 40 and 550. The obtained limits of detection (LOD) for all components included in this extensive screening method are in the range 20–500 ng/ml, which is in compliance with the requirements set by WADA. Besides narcotic and stimulating agents, this method is also capable of detecting several agents with anti-estrogenic activity and some beta-agonists. As an example, a positive identification of hydroxyl-methoxy-tamoxyfen is shown.

Classifying threats with a 14-MeV neutron interrogation system

SeaPODDS (Sea Portable Drug Detection System) is a non-intrusive tool for detecting concealed threats in hidden compartments of maritime vessels. This system consists of an electronic neutron generator, a gamma-ray detector, a data acquisition computer, and a laptop computer user-interface [Strellis et al., 2003, Proceedings of the 2003 ONDCP International Technology Symposium, San Diego, CA]. Although initially developed to detect narcotics, recent algorithm developments have shown that the system is capable of correctly classifying a threat into one of four distinct categories: narcotic, explosive, chemical weapon, or radiological dispersion device (RDD). Detection of narcotics, explosives, and chemical weapons is based on gamma-ray signatures unique to the chemical elements. Elements are identified by their characteristic prompt gamma-rays induced by fast and thermal neutrons. Detection of RDD is accomplished by detecting gamma-rays emitted by common radioisotopes and nuclear reactor fission products. The algorithm phenomenology for classifying threats into the proper categories is presented here.

Potential of Nuclear Quadrupole Resonance in Pharmaceutical Analysis

Nuclear quadrupole resonance is a radio frequency (rf) spectroscopic technique, closely related to NMR, which can be used to detect signals from solids containing nuclei with spin quantum number >1/2. It is nondestructive, highly specific and noninvasive, requires no static magnetic field, and as such is currently used in the detection of explosives and narcotics. Recent technological advances in pulsed NQR methods have shortened detection times, eliminated spurious signals, and enhanced the sensitivity of detection of 14N frequencies, which lie in the low rf range of 0.4-6 MHz, encouraging a wider range of "real world" applications. This Perspective highlights some of the advantages of NQR, the applications in which it could be used, such as the quantification of pharmaceuticals and the identification of polymorphs. Other roles could include detection, analysis, and quality control of pharmaceuticals at all stages of manufacture. Finally, recent advances which enhance even further the sensitivity of detection will be discussed.

Nuclear quadrupole double resonance techniques for the detection of explosives and drugs

Recent work of the Ljubljana group in the nuclear quadrupole double resonance detection of explosives, mines, narcotics and drugs is reviewed with particular emphasis on enhancing low-frequency nuclear quadrupole resonance signals.

External Second Gate, Fourier Transform Ion Mobility Spectrometry: Parametric Optimization for Detection of Weapons of Mass Destruction

Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and robust techniques for the detection of narcotics, explosives and chemical warfare agents. IMS is widely used in forensic, military and security applications. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention (CWC) treaty verification as well as humanitarian de-mining efforts have mandated that equal importance be placed on the time required to obtain results as well as the quality of the analytical data. [1] In this regard IMS is virtually unrivaled when both speed of response and sensitivity have to be considered. [2] The problem with conventional (signal averaging) IMS systems is the fixed duty cycle of the entrance gate that restricts to less than 1%, the number of available ions contributing to the measured signal. Furthermore, the signal averaging process incorporates scan-to-scan variations that degrade the spectral resolution contributing to misidentifications and false positives. With external second gate, Fourier Transform ion mobility spectrometry (FT-IMS) the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters (scan time and sampling rate) to increase the spectral resolution to reduce false alarms and improve the sensitivity for early warning and contamination avoidance. In addition, with FT-IMS the entrance gate operates with a 50% duty cycle and so affords a seven-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system.

Coherent X-ray scatter imaging and its applications in biomedical science and industry

Coherent x-ray scatter (CXRS) imaging refers to the spatially-resolved measurement of the coherent scatter cross-section in localised volume elements (“voxels”) of an extended object. Following a historical introduction to the subject of CXRS, an account is given of the physical principles on which it is based. Representative coherent scatter plots of materials of interest in medical and industrial applications are presented. Several alternative measurement configurations based on angular-dispersive and energy-dispersive x-ray diffraction are described and reasons are discussed which have lead to the adoption of the latter in the bulk of published CXRS investigations. The coherent scatter signal is subject to various degrading effects, such as self-attenuation of the primary and scatter radiations within the object, multiple scatter and statistical (photon) noise. These effects are described and data processing procedures to account for them in order to derive useful quantitative are illustrated. The design of a CXRS device (“RayScan”) in use at the Philips Research Labs is discussed in some detail and representative results obtained with it are presented. The utility of coherent scatter imaging is demonstrated with examples drawn from the fields of tissue characterization in the medical environment, explosives detection for airport security screening purposes and the detection of narcotics.

Mass spectrometric characterization of a high-field asymmetric waveform ion mobility spectrometer

Ion mobility spectrometry (IMS) has become an important method for the detection of many compounds because of its high sensitivity and amenability to miniaturization for field-portable monitoring; applications include detection of narcotics, explosives, and chemical warfare agents. High-field asymmetric waveform ion mobility spectrometry (FAIMS) differs from IMS in that the electric fields are applied using a high-frequency periodic asymmetric waveform, rather than a dc voltage. Furthermore, in FAIMS the compounds are separated by the difference in the mobility of ions at high electric field relative to low field, rather than by compound to compound differences in mobility at low electric field (IMS). We report here the first cylindrical-geometry-FAIMS interface with mass spectrometry (FAIMS-MS) and the MS identification of the peaks observed in a FAIMS compensation voltage (CV) spectrum. Using both an electrometer-based-FAIMS (FAIMS-E) and FAIMS-MS, several variables that affect the sensitivity of ion detection were examined for two (polarity reversed) asymmetric waveforms (modes 1 and 2) each of which yields a unique spectrum. An increase in the dispersion voltage (DV) was found to improve the sensitivity and separation observed in the FAIMS CV spectrum. This increase in sensitivity and the unexpected dissimilarity in modes 1 and 2 suggest that atmospheric pressure ion focusing is occurring in the FAIMS analyzer. The sensitivity and peak locations in the CV spectra were affected by temperature, gas flow rates, operating pressure, and analyte concentration.

New technologies: nuclear quadrupole resonance as an explosive and narcotic detection technique

Possibilities of detecting nuclear quadrupole resonance (NQR) signals in explosives and drugs are considered. Direct and indirect NQR techniques for searching substances are described and the potentialities of various experimental methods are compared.