Examination of Firearms Review: 2007 to 2010 - Interpol

Bonaduce and coauthors used derivatization and GC/MS for the analysis of
sugars in plant gums in mural paintings. The result was one peak for each
compound, providing simple and highly reproducible chromatograms. A decision
scheme for gum identification and the PCA analysis of the relative sugar
percentage contents of reference samples were employed in the identification of
unknowns.[311]
Sutherland discussed products formed from reactions of alcohols with a
quaternary ammonium derivatization reagent to aid in interpreting data obtained
through the use of that reagent. Although the formation of multiple reaction
products is undesirable, the reagent has the advantage of giving very
characteristic fragmentation patterns with EI MS.[312]
Pyrolysis GC/MS was applied by Frade and coauthors to analyze lacquers from
Asia. Py-GC/MS was previously established to be the only technique capable of
distinguishing lacquers, films of which are insoluble and have complex structures.
This article represented a new method to identify the three kinds of Asian
lacquers using their characteristic m/z 104 and 108 mass chromatogram
profiles.[313]
Both derivatization and pyrolysis were used with GC/MS in several additional
studies. Doménech-Carbó et al. analyzed PVA resins in two separate studies.
The first used online silylation Py-GC/MS to characterize the resins, and the new
method led to the unambiguous identification of PVA. In this study, the authors
stated that they thought repeatability was improved as compared to conventional
Py-GC/MS.[314] In the second study, Doménech-Carbó evaluated the
plasticizers in PVA emulsions as potential carbon sources of
microorganisms.[315] Silva and coauthors analyzed PVA paints for plasticizer
content and evaluated the additives (surfactants, coalescing agents, defoamers,
freeze-thaw agents, and thickeners).[316;317] In their work, He Ling et al.
analyzed Chinese binding media to gain knowledge on the materials used in
Chinese artworks. Fingerprint ions for the various types were determined.[318]
Ketone resins used as varnishes were unambiguously identified by Doménech-
Carbó and coauthors. Compared to conventional Py-GC/MS, the online silylation
Py-GC/MS method increased structural information obtained for the materials
studied.[319;320]
Another study by Menke and coauthors applied direct temperature-resolved
mass spectrometry (DTMS) to the detection of four different organic pigment
classes: azo, quinacridone, dioxazine, and phthalocynanine in a variety of 35
reference samples as well as an artist’s specific paint samples. The authors
concluded that the technique provided the best results when used in the negative
ion mode using chemical ionization for the majority of the synthetic organic
pigments that were studied. They discussed that the limited fragmentation
provided a stronger and more readily detectable molecular ion pattern which
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