MaryCarson wrote:Peter Apps wrote:
Another thing to keep in mind is that the LOD of a dog's nose gets down to 10 to the minus 18 molar
Hi, Peter. Since we are "around the water cooler," I suppose I ought to come out of lurk mode and mention that I took this quote and posted it on my facebook page, which is almost entirely about my hobbies/family, and nothing, other than this quote, from my professional life. One of the hobbies I started about a year ago is K9 Nosework with my two dogs. So I posted this quote. Then a friend of mine with no chemistry background at all asked what "molar" was, and proceeded to repost a modified version of the quote on her FB page. She has a lot of followers, so this quote is now rapidly spreading through the nosework community.
So, in case this quote ever gets tracked back to me, is there a reference in the literature for it?
The actual figure given is 10 e-17.67 M, as the threshold for alpha ionone in:
Passe, D.H and Walker, J.C. 1985. Odor psychophysics in vertebrates. Neuroscience and Biobehavioural Reviews 9: 431 - 467.
This is marginally better than rats' thresholds for most compounds. There is no reason to suppose that alpha ionone has any special significance for dogs, and it would be perfectly reasonable to assume that there are some compounds for which their thresholds are lower. On the other hand this is a single figure that most studies do not replicate - it is far more common for dog thresholds to be in the 10e-12 to 10e-14 range and above, but again these tests are run with abitrary compounds like amyl acetate.
Surprisingly enough, given the use that is made of sniffer dogs, there is surprisingly little hard science on what they can do and how they do it. In the tracker and search dog literature all the references ultimately trace back to non-peer-reviewed sources. Training and testing methods have a huge effect, of course, and there is the ever-present handler effect:
Lisa Lit • Julie B. Schweitzer • Anita M. Oberbauer 2011. Handler beliefs affect scent detection dog outcomes. Animal Cognition DOI 10.1007/s10071-010-0373-2.
What dogs do you have and what kind of scent work are they doing ?
Peter