Application Compendium - Agilent Technologies

The spectra from the two sections of the fuel tank
cap were overlaid using the Agilent Resolutions Pro
software so that the data could be visually investigated
to see the spectral differences (Figure 2). With just a
few simple clicks, the software can subtract the two
spectra to isolate the spectral contributions from the
contaminant. The next step in the identifi cation process
is to search the spectrum against a spectral database
using either a custom-built or a commercially-available
library.
Figure 2. Result (purple) of subtracting the spectrum of a contaminated section (red) of the fuel tank cap from that of a non-contaminated section (yellow)
One of the benefi ts of using a custom-built library is
that it allows the analyst to search against their own
proprietary data, at any time. It is also easy to create
custom-built libraries, which can be useful for QA/
QC applications. However, commercial libraries can
provide more advanced data-mining capabilities. The
Resolutions Pro software provides direct access to
the largest commercially-available FTIR libraries —
including a signifi cant number of databases that are
dedicated to polymer and materials applications.
As a result of the library search (custom-built or
commercial), the contamination was identifi ed to be
from the wearing of a red plastic o-ring in a component
of the machinery used during manufacturing.
Conclusions
The study has shown the Agilent Cary 660 FTIR
with Cary 610 FTIR microscope fi tted with a micro-
ATR accessory to be an excellent technique for
the identifi cation of the source of contamination in
polymeric materials (such as the fuel cap investigated
in this instance). Data was collected in 10 seconds and
the spectra were compared visually and subtracted
to gain a better understanding of the contaminant. A
commercially available spectral library search identifi ed
the source of the contamination.
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