RESUMEN
The use of organic peroxides for the preparation of homemade explosives (HMEs) is common among terrorists due to inexpensive precursor chemicals and simple synthetic procedures. Triacetone triperoxide (TATP) is the most notable peroxide explosive, and has been deployed in several terrorist attacks as explosive filling of improvised explosive devices (IEDs). Forensic identification of TATP in pre-blast and post-blast residues, including on-site analysis, poses significant analytical challenges and induces demand for practicable and sensitive detection techniques. This work presents a concept suitable for laboratory and on-site identification of TATP residues in liquid samples (aqueous TATP synthetic waste) and in gas phase. It is based on TATP enrichment from the aqueous or gas phase using different types of passive samplers (polydimethylsiloxane (PDMS) sampling rods and activated carbon sampling tubes (ACST)) and subsequent identification of the explosive by gas chromatography-mass spectrometry (GC-MS) or GC with positive chemical ionization and tandem MS (GC-PCI-MS/MS) analytical techniques. Additionally, investigation of the stability of TATP in aqueous solutions and of the stability of enriched TATP in passive samplers under different storage conditions, as well as development of TATP re-extraction procedures from passive samplers have been performed in this study. The practical use of passive samplers was demonstrated during and after TATP production processes. Moreover, post-blast sampling of TATP under different conditions of controlled blasting events was investigated using the passive sampling concept.
RESUMEN
The thermomorphic fluorous phosphines P((CH(2))(m)()(CF(2))(7)CF(3))(3) (m = 2, 1a; m = 3, 1b) exhibit ca. 600-fold solubility increases in n-octane between -20 (1a = 0.104 mM) and 80 degrees C (63.4 mM) and 1500-fold solubility increases between -20 and 100 degrees C (151 mM). They catalyze conjugate additions of alcohols to methyl propiolate under homogeneous conditions in n-octane at 65 degrees C and can be recovered by simple cooling and precipitation and used again. This avoids the use of fluorous solvents during the reaction or workup, which are expensive and can leach in small amounts. Teflon shavings can be used to mechanically facilitate recycling, and (31)P NMR analyses indicate >97% phosphorus recovery (85.2% 1a, 12.2% other). (19)F NMR analyses show that 2.3% of the (CF(2))(7)CF(3) moieties of 1a leach, in some form, into the n-octane (value normalized to phosphorus). 1a similarly catalyzes additions in the absence of solvent. Yield data match or exceed those of reactions conducted under fluorous/organic liquid/liquid biphase conditions. The extra methylene groups render 1b more nucleophilic than 1a and, thus, a more active catalyst. The temperature dependence of the solubility of 1a is measured in additional solvents and compared to that of the nonfluorous phosphine PPh(3).
