Remote scent collection: bringing the smell to the rat.

APOPO is conducting a series of studies on sampling equipment used for REST operations and training. These studies are at the behest of the GICHD, who provide the main source of funding.

The studies comprise:

• Analyses of the characteristics and variability of the coiled PVC wire filters developed and used by MECHEM, and also used in "RASCO" for airport security purposes;
• Identification, development, and testing of filter materials to be considered for REST sampling;
• Identification, development, and testing of sampling pumps;
• Identification, development, and testing of sample containers.

The initial studies resulted in the improvement of filter materials, packing materials, and backpack pumps. The studies also showed that it was more reliable to collect surface dust, rather than depend on explosives in the vapour phase, which tend to be very unstable due to wind and convection.

APOPO developed two surface dust collection devices in collaboration with the Belgian Design and Study Bureau, Etoile Mechanique. These devices were designed to collect only dust, without the use of filter materials.

Two different prototypes were made:

• One prototype uses compressed gas delivered through a jet flow nozzle to stir up the dust from among the vegetation, then the dust is collected;
• The other prototype uses simple front brushes to stir up the dust, and consequently collects the airborne dust particles using a vortex particle separator.

This latter prototype is currently in use by APOPO for collecting the limited amounts of samples used for research purposes.