We detect chlorinated hydrocarbons (CHC's) in gas mixtures by dissocia
ting the CHC's with a 193-nm laser and measuring the subsequent concen
tration of the CCl fragmentation by means of laser-induced fluorescenc
e. Sub-ppm detection, where ppm indicates parts in 10(6), is achieved
for C2H5Cl with a 10-mm3 measurement volume and integration over 50 la
ser shots. Every other CHC tested is also detectable, with the same or
better detection limits. The CCl forms promptly during the fragmentat
ion laser pulse through unimolecular dissociation of the parent CHC's.
The technique should be a useful diagnostic for CHC incineration syst
ems.