Development of Unidirectional Negative Corona Discharge Ion Mobility Spectrometer for Detection of Explosives / 分析化学

Abstract Ion mobility spectrometry ( IMS) based explosives detectors is wieldy deployed at the check points of airport, etc, so the development of new ionization method to replace the radioactive 63 Ni ion source in IMS is highly demanded. In this study, a novel negative corona discharge was developed for ion mobility spectrometer for rapid detection of trace explosives, which was running in the unidirectional mode to efficiently remove nitrogen oxides and ozone produced from the discharge process. The diameter of target electrode was 3 mm, the distance between the needle and the target electrode was 2 mm, the discharge voltage was 2400 V and the flow rate of drift gas was 1200 mL/min. Under the optimized conditions, the dominant reactant ions was O-2(H2O)n and could be used to directly detect the common explosives, such as trinitrotoluene (TNT), ammonium nitrate (AN), nitroglycerin (NG), pentaerythritol tetranitrate (PETN) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The limit of detection of TNT was 200 pg/μL. These results indicated that negative corona discharge ionization source, with the advantanges of the high sensibility, simple structure and no radioactivity, could be used as a potential and promising ionization source for ion mobility spectrometry to detect explosives.

Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

Partitioning model of the adsorptionof explosives from soils to determineits environmental fate / Modelo de compartimentación de la absorción de explosivosde suelos para determinar su destino ambiental / Modelo de compartimentação da adsorção dos explosivosdos solos para determinar seu destino ambiental

The purpose of this research was to identify the principalsoil characteristics that influence the adsorption of munitionsconstituents (MC) of explosives in soils, through a partitioningmodel to determine the fate of the explosives. Todo that, batch experiments near 1:1 (w/v) soil to solution ratiosreflecting field conditions were conducted using a mixtureof HMX, RDX, nitroglycerine (NG), nitroguanidine (NQ),TNT and 2,4-dinitrotoluene as MC, where the mix of MC wasadsorbed in twenty-five different soils that varied from 4.0to 43.2 % clay content and 0.07 to 18.23 % total carbon, in anexperiment that involved 2 days of adsorption followed byfour consecutive desorption steps. The most important resultwas that for each MC, even if it was in a mixture, were successfullypredicted the partition coefficients using the organiccarbon, cation exchange capacity and extractable iron as theprincipal soil characteristics that determine the fate of theseexplosives.

El objeto de esta investigación consistió en identificar lasprincipales características de suelo que influyen en la adsorciónde constituyentes de municiones (CM) en suelos, medianteun modelo de compartimentación, para determinar eldestino de esos explosivos. Para hacerlo, se llevaron a caboexperimentos de lote (“batch experiments”), de relacionesde cerca de 1:1 (w/v) entre suelo y solución, que reflejabancondiciones de campo, empleando una mezcla de HMX, RDX,nitroglicerina (NG), nitroguanidina (NQ), TNT y 2,4-dinitrotoluenocomo CM, en donde la mezcla de CM fue adsorbida enveinticinco suelos diferentes, que variaban desde 4,0 a 43,2 %de contenido de arcilla y de 0,07 a 18,23 % de carbono total,en un experimento que implicó dos días de adsorción seguidospor cuatro pasos consecutivos de desorción. El resultadomás importante consistió en que para cada CM, incluso enuna mezcla, se predijeron exitosamente los coeficientes departición empleando el carbono orgánico, la capacidad deintercambio catiónico y hierro extraíble, como característicasprincipales del suelo que determinan el destino de talesexplosivos.

A finalidade desta pesquisa era identificar as característicasprincipais do solo que influenciam a adsorção dos constituintesde munições (MC) dos explosivos nos solos, atravésde um modelo de compartimentação para determinar odestino dos explosivos. Para fazer a pesquisa, experimentosem lote perto do solo de 1:1 (w/v) das proporções da soluçãoque refletem condições do campo foram conduzidasusando uma mistura de HMX, de RDX, nitroglicerina (NG),de nitroguanidina (NQ), TNT e 2.4-dinitrotolueno como MC,onde a mistura de MC adsorvida em vinte e cinco solos diferentesque variaram o índice da argila de 4.0 a 43. 2% eo carbono total de 0.07 a 18.23 %, em uma experiência quedemandou 2 dias da adsorção seguidos por quatro etapasconsecutivas de dessorção. O resultado o mais importantefoi que para cada MC, mesmo se estivesse em uma mistura,os coeficientes de partição foram preditos com sucessousando o carbono orgânico, a capacidade de troca e o ferroextraível como as características principais do solo que determinamo destino destes explosivos.

Acetone-Enhanced Negative Vacuum Ultraviolet Photoionization Mass Spectrometry for Rapid Detection of Explosives / 分析化学

In this article, an acetone-enhanced negative photoionization (AENP) source based on a 10. 6 eV vacuum ultraviolet ( VUV) lamp was developed and coupled to a home-made time-of-flight mass spectrometer for rapid detection of trace explosives. In the AENP source, acetone molecules absorbed 10. 6 eV photons and were ionized by single photon ionization to emit photoelectrons. The photoelectrons reacted with O2 , CO2 , etc. in the atmosphere to produce mainly CO-3 negative reactant ions. With this ionization source, common explosives, N-nitrobiz ( 2-hyolorolroxy ethyl )-amine dinitrate ( DINA ) , Tetryl, trinitrotoluene ( TNT ) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), could be detected sensitively, and the limit of detection of 2 pg ( TNT) with a linear range of 3 orders of magnitude was achieved. The simple structure, high sensitivity characteristics make the AENP source as a promising ionization source for mass spectrometry.

Del laboratorio al campo abierto: El uso de protocolos de adaptación y socialización en Rattus Norvegicus / From the lab to the open field: The use of adaptation and socialization protocols with Rattus Norvegicus

El objetivo de este artículo es presentar un protocolo para la adaptación y socialización de sujetos de investigación Rattus norvegicus, cepa Wistar, como parte de un proyecto que busca el entrenamiento de estos animales para la detección de explosivos, tanto en laboratorio como en campo abierto. Se describe el diseño de las habitaciones de los animales, que son distintas de las jaulas-hogar típicas de los bioterios estándar. A continuación, se relaciona la exposición de los animales a diferentes ambientes físicos. Por último, se examina el protocolo de socialización interespecífica de las ratas tanto con humanos como con animales de otras especies.

The goal of this paper is to introduce an adaptation-and-socialization protocol for animal subjects Rattus norvegicus, Wistar strain, into a research project that aims to train these animals to detect explosives, both in laboratory and open field. We describe the design of the home cages, which are different from the vivarium's standard home cages. Next, the exposure of the animals to different physical environments is related. Finally, the inter-specific socialization protocol of the rats with humans and other animals is described.

Caer en la trampa: el accidente por mina antipersonal: la experiencia de los sobrevivientes, Antioquia, Colombia, 2007 / Caught in the trap: survivors’ experiences after landmine accidents, Antioquia, Colombia, 2007

Objetivo: este artículo es el resultado parcial de una investigación llevada a cabo en el contexto de la formación en una maestría en el área de la salud colectiva, cuyo propósito fue interpretar el proceso de integración a la vida cotidiana de los sobrevivientes a accidentes por mina antipersonal, a través de sus relatos para la reconstrucción de experiencias. Metodología: el estudio se hizo con un abordaje metodológico cualitativo etnográfico particularista y focalizado; como técnicas para recolectar la información se utilizaron la entrevista semiestructurada a cuatro participantes y la observación durante la misma. Resultados: en esta publicación se muestra la categoría caer en la trampa, en respuesta a la pregunta ¿cuál es la experiencia con el accidente de los sobrevivientes de minas antipersonal?, que describe el momento de la explosión e incluye el lugar donde sucedió, la actividad que realizaban en ese momento, el objeto con el que fueron heridos, los daños y las sensaciones que les produjo tanto a sí mismos como a sus acompañantes. Conclusiones: la educación en el riesgo de minas es una estrategia adecuada para asegurar que las personas y comunidades se sensibilicen sobre los riesgos, reduciéndolos a un nivel en el que puedan recrear un entorno libre de las limitaciones impuestas por su presencia.

Objective: This report is the partial result of a survey carried out with the purpose of interpreting the process of reintegration to daily life of survivors after landmine accidents, through their testimonies when they recall their experiences.Methodology: A qualitative methodological approach and an ethnographic particularistic focus were employed.The techniques for gathering information were semis tructured interviews to four participants, and observations during them.Results: This paper shows the category caught in the trap in response to the question: How is the experience of landmine accidents survivors? It describes the moment and place of the blast, the activity that was being carried out, the object responsible for the injuries, the harm caused, and the sensations of the survivors and their companions.Conclusions: Education on the risk of landmines is an adequate strategy to make communities and persons aware of the dangers posed by those artifacts.Consequently, the possibility arises to reduce such dangers to levels consistent with the recreation of milieus free from the restrictions imposed by the presence of landmines.

Perforación de la membrana timpánica asociada a trauma por explosivos / Tympanic membrane perforation associated to trauma by explosives

El oído y sus estructuras: membrana basilar, membrana timpánica y cadena oscicular son los órganos más frecuentemente afectados por una onda explosiva. El 38-92% de las perforaciones timpánicas por explosivos cierran espontáneamente, estas marcadas diferencias entre los reportes están influenciadas por múltiples factores como tamaño y localizaciónde la perforación, tipo de explosivo entre otros. El tratamiento es aun controversial: miringoplastia temprana, posicionamiento de un “parche” sobrela perforación y observación son recomendados. Objetivo: Determinar la severidad de las perforaciones timpánicas por explosivos y sus efectos en la audición. Diseño y métodos: Este es un estudio retrospectivo en soldados afectados por explosiones en combateen Colombia tratados en nuestra institución. Los datos recolectados incluyeron edad, género, localizacióny tamaño de la perforación, síntomas, resultados audiológicos (PTA), cierre espontáneo y tipo de explosivo.Resultados: Un total de 81 perforaciones timpánicas fueron encontradas. Las minas terrestres fueron los tipos de arma más utilizadas (57%). La mayoría de las membranas (83%) presentaron rupturas grandes (grados II, III, IV). Hipoacusia leve y moderada fueron encontrados en 42% y 25% respectivamente. La localización no se encontró relacionada con la severidad de la pérdida auditiva. Encontramos una rata de cierre espontáneo muy baja (15,3%), entre aquellos que requirieron cierre quirúrgico la cadena oscicular se encontró integra en 64%. Conclusión: La mayoría de los pacientes afectados por explosivos que requiere contacto directo para su detonación (minas terrestres) presentarán perforaciones timpánicas grandes, con poca oportunidad de cierre espontáneo. A estos pacientes se les debería realizar cierre quirúrgico temprano para evitar complicaciones tardías...

The ear and its structures: basilar membrane, tympanic membrane and ossicles are the most sensitive organs injured during detonation of explosives (blast overpressure). The 38-92% of the tympanic membrane perforations due to explosives closes spontaneously; these remarkable differences areinfluenced by multiple factors such as size, location, type of weapon, among others. Treatment is still controversial: early miringoplasty, patching of the perforated drum or observation, have been all recomendated. Objective: To determine the severity of tympanic membrane perforations by explosives and its effect on hearing. Study design and methods: This is a retrospective study of soldiers injured in combat explosions in Colombia and treated at our institution. Data collected included age, gender, location and grade ofperforation, symptoms, ossicular damage, audiogram results (PTA), healing rates and type of explosive.Results: A total of 81 tympanic membrane perforations were found among these patients. Landmines was the most weapon used (57%) affecting our population. Most of the tympanic membranes (83,3%) had large ruptures (grade II, III, IV). Mild to moderate hearing loss was founded in 42% and 25% respectively. Location of the perforation was not related to severity of hearing loss. We found a very low spontaneous healing rate (15,3%). Among those who had surgical intervention, ossciles integrity was found in 64%. Conclusion: Most patients injured by explosives which require close contact to be detonated (landmines)may have large tympanic membrane perforations with little chance of spontaneous healing. These patients should be offered prompt surgical intervention to avoid later complications...

Analysis of emulsion explosives residues by LC/MS / 重庆医科大学学报

Objective:To use liquid chromatography/mass spectrometry to detect single-oleic acid sorbitan ester(SP-80)of emulsion explosives residues.Methods:Samples were collected after the ultrasonic cleaning solution with hexane,then filtered,and the filtrate were dried up with the rotary evaporator,dissolved in methanol,and then centrifuged.Chromatographic conditions were as follows:column phenomenex luna of C18 3?m(100?2.0 mm)(ID),pre-column Luna of C18 3?m(10?2.0 mm)(ID),mobile phase volume ratio of 1∶200 aqueous solution of acetic acid,isopropyl alcohol of 10∶90; flow rate of 0.20 ml/min,and column temperature of 35℃.MS parameter included drying nitrogen gas temperature of 200℃,nebulizer flow of 1.5 L/min,and detection voltage of 1.40 kV.Results:The linearity range of the assay for SP-80 was 0.2～1 mg/ml with correlation coefficient of 0.997 8,and the detection limit of 1?g/ml.3 extracts detected no significant difference.SP-80 were detected in two tapes emulsion explosives.Conclusion:The method of LC/MS can be used to infer the types of explosives for its operative simplicity, small sample requirement,high sensitivity,and wide linear range.

Blast injuries of the hand

Blast injuries of the hand, brought above by the use of explosives in fishing, are increasingly seen. This article discusses the various considerations in the repair of the injuries caused and presents a summary of the cases managed. (Summary)