Stefan Ek

Extraction of explosives from soil followed by gas chromatography–mass spectrometry analysis with negative chemical ionization

A new, simple and accurate method for extraction of explosives from soil was developed and validated. The method includes one hour gentle extraction of compounds from soil in acetonitrile:dichloromethane 50:50 at 30°C. Further analysis was made with GC-MS using cool on-column injection and negative chemical ionization. The method increased the recovery of the more volatile products, generated higher accuracy and was extensively time-saving compared to the conventional EPA (US Environmental Protection Agency) 8330 method. Applications are demonstrated on commercial reference materials.

Scalable Synthesis of 1,1-Diamino-2,2-dinitroethene Without Hazardous Intermediates or by-Products

A process for the preparation of 1,1-diamino-2,2-dinitroethene suitable for scale-up was developed. The crucial features to allow scalability and enhance the process safety were the improved synthesis of 2-methoxy-2-methylimidazolidine-4,5-dione and its conversion into 2-hydroxy-2-methylimidazolidine-4,5-dione, which is a new intermediate in the synthesis of 1,1-diamino-2,2-dinitroethene. Its nitration produced 2-(dinitromethylidene)-imidazolidine-4,5-dione, whose hydrolysis into 1,1-diamino-2,2-dinitroethene was further improved. The use of trifluoroacetic acid to remove sulfuric acid prior to hydrolysis is no longer required. The described procedure yields no hazardous intermediates such as dinitromethane or 2-(dinitromethylidene)-5,5-dinitrodihydropyrimidine-4,6(1H,5H)-dione. Thus, the process safety was enhanced in comparison with the commercial production process starting from 2-methylpyrimidine-4,6-dione.

Energetic Plasticizers Based on gem-Dinitrodiols

In this article, the syntheses and attempts at synthesis for the preparation of gem-dinitrodiols and their derivatives are outlined. The three gem-dinitrodiols described are 2,2-dinitropropane-1,3-diol, 3,3-dinitropentane-1,5-diol, and 4,4-dinitroheptane-1,7-diol. The nitrooxy, azido, and azidoacetoxy derivatives of the latter were prepared and are compared to derivatives of the first, which were presented in a previous article. The tedious and expensive synthesis of pentanediol precluded its use as an intermediate. Only one compound both had excellent glass transition temperature and was thermally stable. This compound was 4,4-dinitro-1,7-diazidoheptane.

Localisation of threat substances in urban society - LOTUS: a viable tool for finding illegal bomb factories in cities

Results of dispersion experiments and dispersion modelling of explosives, drugs, and their precursors will be presented. The dispersion of chemicals evolving during preparation of home made explosives and a drug produced in an improvised manner in an ordinary kitchen has been measured. Experiments with concentration of hydrogen peroxide have been performed during spring and summer of 2009 and 2010 and further experiments with concentration of hydrogen peroxide, synthesis and drying of TATP and Methamphetamine are planned for the spring and summer of 2011. Results from the experiments are compared to dispersion modelling to achieve a better understanding of the dispersion processes and the resulting substances and amounts available for detection outside the kitchen at distances of 10-30 m and longer. Typical concentration levels have been determined as a function of environmental conditions. The experiments and modelling are made as a part of the LOTUS project aimed at detecting and locating the illicit production of explosives and drugs in an urban environment. It can be concluded that the proposed LOTUS system concept, using mobile automatic sensors, data transfer, location via GSM/GPS for on-line detection of illicit production of explosive or precursors to explosives and drugs is a viable approach and is in accordance with historical and todays illicit bomb manufacturing. The overall objective and approach of the LOTUS project will also be presented together with two more projects called PREVAIL and EMPHASIS both aiming at hindering or finding illicit production of home made explosives.