Canine olfaction

Probably the oldest need for trace detection was for the detection of poisons. Food tasters fulfilled that role, as did canaries when used by miners to warn of poisonous atmospheres underground. In more recent times, society has required the detection of other chemicals. Often a trained dog meets that need. Canine olfaction wiU be discussed in Chapter 3. 

Plastic explosives contain one or more of the explosives listed above, moulded in an inert, flexible binder. Because powders do not readily hold a shape and TNT is the only common melt-castable explosive, most of the explosive powders (RDX, HMX, PETN, 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)) are plasticized to make a mouldable material, for example, C-4, Semtex H, PE4, sheet explosive. A variety of plasticizers are added, but the maximum level is usually 10-15% because most plasticizers are inert and would degrade explosive output. Plastic explosives were originally developed for convenient use in military demolitions but have since been widely used in terrorist bombs. For detection techniques that rely on vapour signatures, such as canine olfaction, it is worth considering that the plasticizer is much more volatile than the explosive component. 

Griffin, R. W. and Beidler, L. M. (1984). Studies in canine olfaction, taste and feeding a summing up and some comments on the academic-industrial relationship. Neuroscience and BioBehavioral Reviews 8,261-263. 

K.M. Reese, Canine Olfaction Tried for Detecting Pollutants, Chem. Eng. News 63(37), 84, Sept. 16 (1985). 

Beidler, L.M., M.E. Rashotte, J.C. Smith R.W. Griffin. 1984. Neuroscience and Biobe-havioral Reviews Studies in Canine Olfaction, Taste and Feeding. Ankho International, Inc. Fayetteville, New York. 

Fig. 2. Sagittal cross-section of canine skull identifying key olfaction components (portion of image from...

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