Examination of Firearms Review: 2007 to 2010 - Interpol

Micro XRD analysis was discussed for pigment analysis by Nel and coauthors in
proceedings from the AICCM National Conference in Brisbane, Australia in 2007.
In this work, the authors observed that the technique can complement other nondestructive,
non-invasive, and in-situ technologies, but was best applied to art
and artifacts where the pigments were pure, mixing of pigments was minimal, or
where the pigments within a mixture did not have significant differences in their
absorption coefficients.[290]
Van der Snickt and coworkers describe a combined micro-XRD and micro-
Raman mobile device (PRAXIS) and compared the PRAXIS results to those
obtained from synchrotron micro-XRD. The latter technique was required to
show the presence of lead white in an illuminated manuscript. The authors also
mention that despite all the information obtained from the aforementioned
techniques, a supplementary organic method would also have been helpful in
identifying some remaining unidentified components.[291] Herrera et al. did in
fact combine multiple analytical techniques, including organic and inorganic
analysis methods, in combination with synchrotron XRF and XRD, for the
analysis of paintings.[292] A novel approach was taken by Ferreira and
coauthors in the use of synchrotron X-Ray microtomography to obtain threedimensional
data, thereby allowing for the reconstruction of sample surface
morphology.[293]
19. Nuclear Magnetic Resonance (NMR)
One article was found during the review period that used NMR for paint analysis.
In the article, Presciutti et al. used a compact and mobile NMR sensor to
measure the thickness of paint layers in situ and to investigate binder aging. The
work claimed to be the first step towards characterizing the three-dimensional
morphology of different layers in paintings without contact.[294]
20. Laser induced breakdown spectroscopy (LIBS)
In 2007, Giakoumaki and coauthors published a review article outlining the basic
physical principles and analytical features of LIBS, with a description of the
instrumentation and technology, examples of LIBS use (including a section on
pigments), and future prospects.[295]
Osticioli and coauthors set out to determine the best working conditions for LIBS
to remove the least amount of material during analysis while achieving the best
quality in spectral response.[296] The optimized conditions were applied to a
real painting, in which most of the inorganic pigments were identified. A
significant limitation, however, was the alteration of pigments with regards to
discoloration and darkening. This work was furthered in a study by the same
lead author in which the effects of light exposure on egg white and egg yolk films
was evaluated.[297]
146