Abstract:
Laser micropyrolysis gaschromatograpby-mass
spectrometry is used for the analysis of paint, photocopier toner, and
synthetic fiber materials to test the forensiopotential of this emerging
technology. It uses a laser microprobe to selectively target very
small parts of the materials for GC-MS· analysis. Whereas the paint
and the toner samples were amenable to direct laser pyrolysis, the
synthetic fibers proved transparent to the 1064 urn laser radiation.
The difficulty with the fibers demonstrates that a specific laser wavelength
may not be appropriate for all types of materials. Nevertheless,
the fibers were able to be indirectly pyrolyzed by impregnation
in a strongly absorbing graphite matrix. A vast array of hydrocarbon
pyrolysates was detected from the different materials studied.
Unique product distributions were detected from each sample and in
sufficient detail to facilitate individual molecular characterization
(i.e., molecular fingerprinting). The integrity of the laser data were
confirmed by comparison to data obtained from the same samples by
the more conventional pyroprobe pyrolysis GC-MS method. The
high spatial resolution and selectivity of the laser method may be advantageous
for specific forensic applications, however, further work
may be required to improve the reproducibility of the data.
