Wyniki wyszukiwania - BazTech

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The Effect of Humidity and Dopants on the Detection of TNT Vapor by Differential Ion Mobility Spectrometry (DMS)

Karpińska Monika, Pawłowski Wojciech, Zalewska Anna

Central European Journal of Energetic Materials

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2024

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Vol. 21, no. 3

298--319

EN

The aim of this study was to investigate the effect of an external factor, i.e. humidity, on the detectability of TNT vapor by Differential Ion Mobility Spectrometry (DMS). The values of TNT signal amplitude and asymmetric voltage were measured as a function of relative air humidity. The influence of the use of a semi-permeable membrane and the additive agent - dopant (nicotine and dichloromethane) on the detection under varying air humidity conditions was also investigated. The analysis of the obtained results confirms that the introduction of dopant to the analyzed stream contributes to the change of TNT detection parameters. The DMS detector allows you to observe the signal in two polarizations (positive and negative), which is an advantage compared to the competitive FAIMS method. It was observed that water vapor content above 30% causes the formation of two analytical signals for TNT. This, in turn, may improve the identification process. The addition of nicotine and dichloromethane reduces the amplitude of the air signal, which has a beneficial effect on TNT detection.

2

Development of explosives detection method based on FAIMS (Field Asymmertric Ion Mobility Spectrometry) and thin layer chromatography (TLC)

Tomaszewski Waldemar, Perchaluk Paweł, Maksimowski Paweł, Gołofit Tomasz

Materiały Wysokoenergetyczne

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2021

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T. 13

112--122

EN

A new method of hyphenation of thin layer chromatography (TLC) and field asymmetric ion mobility spectrometry (FAIMS), is presented. Coupling chromatography with spectrometry enables the simultaneous separation and identification of individual species. During chromatographic experiments the elution was carried out using normal- and reversed-phase systems. The detection was performed with MO-2M and PILOT-M handheld detectors. The chromatographic bands were located using ultraviolet detection and a spray reagent containing diphenylamine. The bands containing explosives were separated and placed in thermal desorbers of the detectors. They were applied as vapour intensifiers. During experiments, a more effective way of desorption from TLC sheets using a conventional dry block heater was demonstrated. The best results were obtained using the MO-2M detector an normal-phase separations. By applying such separation, it was possible to detect 10 μg of trinitrotoluene, hexogen, pentaerythritol tetranitrate and CL-20 on TLC plates.

PL

W pracy przedstawiono połączenie dwóch metod: chromatografii cienkowarstwowej (TLC) oraz spektrometrii FAIMS. Połączenie (sprzężenie) metody chromatograficznej np. z metodą spektrometryczną pozwala na szybki rozdział mieszaniny i identyfikację jej składników. Do rozdziałów chromatograficznych zastosowano normalny lub odwrócony układ faz, jako detektory użyto spektrometry MO-2M i PILOT-M. Pasma chromatograficzne lokalizowano w promieniowaniu ultrafioletowym lub po zastosowaniu odczynnika wywołującego z difenyloaminą. Po lokalizacji na rozwiniętych płytkach pasm chromatograficznych wycinano ich fragmenty, które desorbowano termicznie w fabrycznych desorberach urządzeń lub na zaprojektowanym stanowisku z podgrzewaczem laboratoryjnym. Desorpcję termiczną zastosowano w celu zwiększenia emisji par substancji wybuchowych z płytek krzemionkowych. Stosując detektor MO-2M oraz płytki krzemionkowe rozwijane w normalnym układzie faz zidentyfikowano w rozdzielonych pasmach chromatograficznych, zawierających po 10 μg, heksogenu, trotylu, pentrytu oraz CL-20.

3

Regularities of the energy of formation field in the explosion of a conical charge

Kravets Viktor, Zakusylo Roman, Sydorenko Yuri, Shukurov Azer, Sałaciński Tomasz, Zakusylo Daryna

Central European Journal of Energetic Materials

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2019

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Vol. 16, no. 4

533--546

EN

The process of formation of the energy field by the explosion of a conical charge has been mathematically simulated. The features of the development of the energy field, depending on the point of initiation of the truncated cone explosive charge, were determined. The complex nature of the use of a charge at the bottom of a borehole with an intermediate conically-shaped detonator is discussed. Possible technological directions for using a charge with a complex shape are proposed.

4

Stężanie par materiałów wybuchowych

Błądek J., Cudziło S., Jakubowska I., Maławska A., Wojtas J.

Biuletyn Wojskowej Akademii Technicznej

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2011

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Vol. 60, nr 2

39-46

PL

Przedstawiono wyniki badań nad zastosowaniem instrumentalnej chromatografii cienkowarstwowej do pomiaru skuteczności retencji wybranych materiałów wybuchowych (TNT, NG i TAT P) na adsorbentach stosowanych w analizatorach par MW lub produktach ich rozkładu. Dowiedziono, że wstępne stężanie może być wykorzystane wyłącznie do detekcji par MW; analizy ilościowe nie są możliwe, ponieważ nie zaobserwowano liniowych zależności między czasem retencji a masą zaadsorbowanych MW. Wykazano też, że szybka detekcja stężonych par MW jest możliwa jedynie przy użyciu detektorów o wykrywalności granicznej rzędu nanogramów.

EN

Application of the instrumented thin-layer chromatography (TLC) for the evaluation of retention effectiveness of chosen explosives (TNT, NG, TAT P, PETN ) on some adsorbents used in explosive vapor (or the explosive decomposition products) analyzers is presented. It was confirmed that the initial preconcentration can be used only for detection of explosives; quantitative analysis cannot be performed because there is no linear dependence of the adsorbed mass of an explosive on the retention time. It was also shown that fast detection of the concentrated explosive vapor is possible only with using detectors whose detection limits are at a level of nanograms.

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Computational Investigation of Amine Complexes of 2,4,6-Trinitrotoluene

Politzer P., Murray J. S., Koppes W. M., Concha M. C., Lane P.

Central European Journal of Energetic Materials

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2009

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Vol. 6, nr 2

167-182

EN

Using the B3PW91/6-31G(d) computational procedure, we fnd two types of complexes to be formed between aliphatic amines and 2,4,6-trinitrotoluene (TNT). Type 1 are noncovalent, primarily electrostatic interactions that occur in the vicinities of the NO2 groups; Type 2 are δ-adducts, at carbons 1, 3 and 5. In Type 1, the TNT framework is very little affected. In Type 2, however, the site of the complex becomes quasi-tetrahedral, with longer bonds to its neighbors in the ring; the C-NO2 bonds are shortened. The Type 1 complexes have weakly negative (attractive) interaction enthalpies. For one of them, utilizing a chargetransfer formalism, we obtained a wave length for an electronic transition to a low-lying dative excited state that is in good agreement with observed values. The Type 2 interaction enthalpies are near-zero or even positive; however all of the complexes correspond to energy minima (no imaginary frequencies). For one of the Type 2, a transition state to a nitronic acid was found, with an activation enthalpy of only 5.6 kcal/mole. This indicates a possible route for amine-induced decomposition of TNT.