A tester to detect the presence of a target substance includes a housing that can be mounted on a shipping container; a chemical reservoir insertable into the housing; a disc or an automated cartridge containing test filter swipes adapted to receive particles or vapor, and a chemical from the chemical reservoir, the test swipe including one or more chemically treated pads; a camera to capture an image from the test swipe; a processor coupled to the camera to process the image to detect the target substance; and a transmitter coupled to the processor to transmit a test result to a remote computer.