Patent ID: 8287811

Claim:
A method for determining the presence of a target analyte comprising: providing a passive sampling device, said passive sampling device comprising a waveguide having first and second sides; an AFP compound carried by said first side of said waveguide, said AFP compound fluoresces when exposed to ultraviolet light, said fluorescence of said AFP compound is quenched by exposure of said AFP compound to a target analyte; a reference standard carried by said second side of said waveguide, said reference standard, when exposed to ultraviolet light, fluoresces at a wavelength distinct from the fluorescence of said AFP compound, and wherein fluorescence of said reference standard is not substantially quenched when said reference standard is exposed to said target analyte; providing a passive sampling device reader, said passive sampling device reader comprising a UV light source, at least three short-pass filters and a photomultiplier tube suitable for detecting fluorescent emissions; using said passive sampling device reader to determine a pre-exposure value for said passive sampling device prior to exposure of said passive sampling device to said target analyte by contacting said passive sampling device with UV light thereby generating a fluorescent emission from said AFP compound and from said reference standard measuring the pre-exposure fluorescent emissions for said AFP compound and said reference standard; exposing said passive sampling device to said target analyte by placing said passive sampling device in an area to be tested for said target analyte for a period of time thereby exposing said passive sampling device to the surrounding environment; collecting said passive sampling device and; and, using said passive sampling device reader to determine the capture and retention of said analyte by said AFP compound by contacting said passive sampling device with UV light thereby generating a post-exposure fluorescent emission from said AFP compound and from said reference standard and comparing said post-exposure fluorescent emissions to said pre-exposure fluorescent emissions for said passive sampling device.