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...ions 35 - 300 amu. Identification of explosives was carried out by comparing the retention times and mass spectra of the substances in the studied samples and reference samples.

As a result, it was established that trace amounts of 2,4,6-trinitrotoluene (TNT) - a high explosive - are present in all swabs, and trace amounts of RDX (hexogen) - a high explosive - are present in swabs from fragments from box No. 3 (item 8) and tampons (items 14, 15).

Thus, the composition of the detonated charge of the explosive device included TNT and RDX - high explosives.

TNT and RDX can be used as explosives both in individual form and in the form of mixtures with other components (for example, with ammonium nitrate, aluminum).

To detect trace amounts of ammonium nitrate, a study was conducted using the IC (Ion Chromatography) method on a "Star" liquid chromatograph from "Varian" (USA). The eluent was supplied using an isocratic pump model 9002 from "Varian" (USA).

To separate anions in the studied mixture, an Elsian-6-Kank column from "Elsiko" (Russia) filled with anion-exchange resin was used, a 2x20 mm guard column filled with grafted C18 phase with a particle size of 40 μm, and a BTS AG suppression column from "Biotronic" (Germany). Chromatography of the sample was carried out in isocratic mode with a carbonate buffer containing 0.002 M Na2CO3 and 0.002 M NaHCO3. Eluent flow rate 2 ml/min.

To separate cations in the studied mixture, a BT IV KA column from "Biotronic" (Germany) was used, a 2x20 mm guard column filled with grafted C18 phase with a particle size of 40 μm, and a BTS KG suppression column from "Biotronic" (Germany). Chromatography of the sample was carried out in isocratic mode with a buffer containing 0.002 M HNO3. Eluent flow rate 2 ml/min.

Detection of inorganic components was carried out by absorption in the UV region at a wavelength of 192 nm using a "Star" model 9050 photometric detector from "Varian" (USA) and a model 550 conductometric detector from "Alltech" (USA). Injection into the chromatograph was performed using a microsyringe and an injector with a 100 μl loop. Before injecting the studied samples, a blank experiment was conducted to check the purity of solvents and glassware. For calibration, standard freshly prepared solutions of anions in water in the concentration range of 0.1-10 μg/ml were used.

As a result, it was established that ammonium ions and nitrate ions are present in the aqueous extracts of swabs from all studied objects. Their background level was determined based on the results of the analysis of soil sample extracts. It turned out that in the swabs from fragments (item 1) and from the tampons specified in item 15, the amounts of nitrate ion and ammonium ion (about 10 mg/l) slightly exceed the natural background level.

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