The Analysis And Application Of Volatile Components Of Common Explosives

Explosives are extremely destructive,endangering the stability and safety of society.An explosion may lead to major casualties and huge economic losses.Accurate location of explosives before explosion can reduce the occurrence of explosion cases.The instruments used to detect explosives mainly include odor scanner,gas chromatography-mass spectrometer(GC-MS)and liquid chromatography-mass spectrometer(LC-MS).The animals used to detect explosives are mainly dogs.Dogs have a very sensitive olfactory sense,and have the advantages of quickness and flexibility.After training,they can accurately locate the positions of explosives in time.In the practice of security inspection and criminal investigation,police dogs are mainly used to identify and locate explosives.Studying the volatile components of explosives is helpful to understand the mechanism of police dogs identifying explosives and provide a theoretical basis for daily training of police dogs.This paper selected five common and easily available explosives: 2,4,6-trinitrotoluene(TNT),cyclotrimethylenetrinitramine(RDX),pentaerythritol tetranitrate(PETN),2,4-dinitroanisole(DNAN),2,4,6-trinitrophenol(TNP),and three new types of peroxides which are easy to synthesize: triacetone triperoxide(TATP),diacetone diperoxide(DADP)and hexamethylene triperoxide diamine(HMTD).The chemical components of explosives were detected by GC-MS and LC-MS,and the volatile components of explosives were analyzed by headspace with GC-MS.In addition,two pretreatment methods of headspace and solid phase microextraction(SPME)were used to optimize the conditions to obtain the best extraction method for analyzing the volatile components of explosives.The results showed that the volatile components of TATP and DADP were both the parent compounds,while the volatile components of TNT and DNAN were not only parent compounds,but also included their own nitration synthesis intermediates and by-products,such as dinitrotoluene,4-nitroanisole,2,6-dinitroanisole,etc.The contents of synthetic intermediates in explosive volatiles were generally higher than that of the parent compounds.Due to the low volatility of RDX,PETN,TNP and HMTD,the volatile components were not detected in this study.Based on the research on the volatile components of explosives,the application of explosive odor packs in odor search training of police dogs was explored.In order to verify the assumptions,an exploratory study was conducted to establish specific training methods to train police dogs.Two Jack Russell dogs and one Springer dog were trained in the ability to search for the TNT explosives odor.The training contents included basic search form training,odor contact training,warning training,selection of three types of environmental training: brick pile,luggage and vehicle,room search training,contact new odor training,ability complexity training,and so on.All three dogs passed the assessment and could successfully detect TNT explosives and applied them in actual combat.Training data showed that dogs' response became more sensitive and learning ability was enhanced after odor training.