engleski

Detection of explosives in war affected areas of Croatia by liquid chromatography/ tandem mass spectrometry

A simple and highly selective method for the simultaneous determination of six different explosives, including 2, 4-dinitrotoluene (DNT), 2-amino-4, 6-dinitrotoluene (A-DNT), 2, 4, 6-trinitrotoluene (TNT), 1, 3, 5-trinitrobenzene (TNB), octahyhro-1, 3, 5, 7-tetranitro-1, 3, 5, 7 tetrazocine (HMX) and hexahydro-1, 3, 5-trinitro-1, 3, 5 triazine, (RDX), in soil, was developed. The analytes were extracted from the soil samples using ultrasonic extraction. Filtered methanol extracts were diluted with ultrapure water in the ratio 1:1 prior analyses. The extracts were analysed by reversed-phase liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (ESI-MS/MS). The detection of all target analytes was performed in negative mode using single reaction monitoring (SRM). Quantification of all target compounds was performed using external calibration. A good linearity, with correlation factors above 0.99, was achieved for all analytes. The linear range of the measurement varied between 0.2-20 ng for TNT and DNT and 0.02-2 ng for all other analytes, due to differences in the ionisation efficiencies. Detection limits based on 1 g soil sample ranged from 0.5 to 100 ng/g for HMX and TNT, respectively. Spiking of soil sample extracts with standard mixture of explosives indicated that co-extracted organic matrix did not have a significant impact on chromatographic behaviour and quantitation of the target analytes. The method was applied for the analysis of 60 soil samples from several war-affected regions of Croatia. In most of the analysed samples concentration of all analytes was bellow the detection limit. However, at some locations enhanced concentration of explosive compounds (up to 20  g/g of RDX and 2.7  g/g of TNT) was found.

-

nije evidentirano