NO and PO photofragments as trace analyte indicators of nitrocompounds andorganophosphonates

Laser photolysis that releases characteristic photorragments, combined with laser-induced fluorescence (LIF) that subsequently monitors them, facilita te detection of trace-vapor analytes in air. The feasibility of the techniq ue is demonstrated for nitrocompounds and organophosphonates detection. Usi ng one-color and two-color lasers, respectively, the representative NO and PO photofragments were tagged. Employment of longer wavelengths for photodi ssociation, and where possible also for LIF, than for fluorescence collecti on, obstructs background fluorescence and in the former compounds also prev ents interference of ambient ground state NO.