So you’re bad guy has buried his victim somewhere on his vast farm. Your sleuth knows this but can’t prove it. Locating the corpse is critical to making the case. Search teams and cadaver dogs are brought in but the days drag by with no results.
Electronic noses were developed for this very circumstance. These devices are basically gas chromatographs. They sample air near the grave where the molecules of decomposition percolate up from the decaying corpse. Thomas Bruno, a physicist at the National Institute of Standards and Technology (NIST) recently reported in New Scientist the development of a handheld sniffer device, which should allow investigators to more quickly cover large areas, allowing for more timely corpse location.
I earlier posted a note about microfluidics. This device incorporates some of that technology. The device contains a very thin capillary tube whose inner surface is coated with aluminum oxide. Air is then sucked into the tube. If this air contains any of the various amines produced by decomposition, these molecules will combine with the aluminum oxide. This new amine-aluminum oxide combination can be detected using UV light.
This device is still in the developmental stage but could prove to be a very useful tool for corpse location.