The Development Of TNT Odor Replacements For Explosive Detection Dogs And Its Bio-safety Assessment

Explosive detection training of the police dog is a process during which the dogs will find the explosives and then give warning properly using one or several explosives odor as scent source under certain conditions.In the detect explosives trainings of TNT,in order to cultivate the odor search ability we should use appropriate explosives as scent source to establish these odor associations for dogs.TNT odor replacements in dog detect explosive trainings have already been applied to the dog training in America and Canada.The replacements have the advantages of simpleness,convenience andpracticability and have achieved good effects in the dog training.However,our country has not commercial and special odor replacements in dog training so far.What's more,in odor association trainings,the collection process of odor source is time-consuming and inconvenient as well as the concentration of scent source cannot be quantified.More importantly,there exists potential security risks.Therefore,the development of special odor replacements for the dog training is an innovative technique and will fill the gaps in the explosive detection trainings of our country,which will also benefit the service of actual combat.In order to confirm that TNT odor replacements could be applied to the explosive detection trainings of dogs by the experimental data,the chemical components of TNT odors were analyzed and TNT odor replacements were compounded.Then the product performance test were conducted via forward and reverse trials and bio-safety assessment for TNT odor replacements were carried on to observe whether the TNT odor replacements would have a negative impact on health and training behavior of the dog under the normal training condition,which would provide experimental basis for the security application of TNT odor replacements.Experiment 1:Development of special odor replacementsA method for determination of odorants had been developed with Gas Chromatography-Mass Spectrometry(GC-MS)combined with Head Space Solid Phase Micro-Extraction conditions of SPME were optimized.After odor enrichment by headspace solid phase micro extraction-gas chromatography(SPME-GC),the chemical components of TNT odors were analyzed which is based on the separation ability of gas chromatography and qualitative and quantitative analysis ability of mass spectrum,thus providing reference for scent simulation of TNT.According to the result of chemical components analysis,to ensure that the training effect of the odor replacements is coincident with that of the original odor,we made up analog odor of which the composition's ratio was similar to the original scent using extraction and separation materials and related chemicals.And then,simulation odor that had been ready were adsorbed on odor adsorption medium,such as degrease gauze.Finally vacuum packaging technology was used for encapsulation to prevent reducing the quality of the replacements because of the spread of the odor.Experiment 2:performance evaluation of the TNT odor replacementsThis study included forward and reverse trials.In the forward trial,we used explosive detection dogs which had good TNT search capability to test the validity of TNT odor replacements.10 TNT search dogs were applied to TNT search capability state test,only their search capability state were qualified and then can be used to performance evaluation of the TNT odor replacements.In the reverse trial,TNT odor replacements were applied to the training of the explosive detection dogs.23 Labrador retriever were allocated randomly into two groups named group 1 and group 2.The dogs in group 1 were trained using the TNT odor replacements while the dogs in group 2 were trained using the original TNT.The results showed that the average odor contact time of group 1 was 14 d while that of group 2 was 17 d,and there was significant difference between two groups(P<0.05).In the four kinds of training including lawn,cars,bags and rooms,the efficiency of TNT search was similar and not significant(P>0.05).The accuracy of group 1 was 92.72%while that of group 2 was 88.55%,and there was no significant difference between two groups(P>0.05).Conclusions:the training effect of the odor replacements were coincident with that of the original odor.Experiment 3:Bio-safety assessment for TNT odor replacementsBefore the odor inhalation of TNT odor replacements,some indexes about 12 Labrador retriever 's health condition should be examined to be used as control group.These indexes included breath,appetite,spirit,faeces and urine training behavior,physiological and biochemical index.The experimental dogs need be worn TNT odor replacements for 6 hours every day(9:00-12:00;14:00-17:00),Blood samples were collected every week for analysis of blood routine and blood chemistry.The results showed that the experimental dogs about breath,appetite,spirit,faeces and urine didn't appear unusual.Compared with the comparative group there was no significant difference about the indexes of blood routine and blood chemistry(P>0.05).All the experimental dogs didn't appear abnormal behavior.Conclusions:the TNT odor replacements weren't inherently bad for the dogs' health and training behavior.Therefore TNT odor replacements can be applied to the practice in safety.