just because everything has a vapor pressure, and even a measurable one well below the boiling point, hardly seems worthy of not being allowed to call a salt with a very low vapor pressure at room temp "non-volatile". this is not exactly an uncommon context for that phrase.
an article by a PhD working for Customs, Journal of Forensic Science 46(5), 1014 (2001): "It is well established that canines alert to the odor associated with training materials, drugs
in this case, rather than the material itself." the google cache of the article
an article of interest that i wish that i could see.
this would actually be more on-topic as it includes MDMA
there are also some related articles in the Proceedings of the American Academy of Forensic Sciences, but no one is going to share those here.
this NIOSH pdf
indicates that US Customs currently uses methyl benzoate (cocaine
), acetic acid (heroin
, piperonal (MDMA), and benzaldehyde (methamphetamine
) for its dog training.