Inorganic components, identification

Another approach is to separate the solvent from the sample before a spectrum is obtained. Because HPLC is often used with a combination of volatile eluents and organic compounds that are not volatile, the solvent can be removed and the isolated component analyzed by FTIR [13]. FTIR is not particularly useful for the identification of inorganic components, particularly ions. 

In the following sections, we outline the possible scope of this new field and we illustrate the use of materials science methods in criminalistics by discussing two examples the recovery of erased serial numbers and the identification of papers from their inorganic components. 

A satisfactory test for the identification of FDR on a suspected firer has been sought by forensic scientists for many years. A satisfactory test would be one that is simple, reliable, fast, inexpensive, and conclusive. Until recently efforts have concentrated mainly on the detection of inorganic components of FDR and encompass qualitative and quantitative methods, culminating in the particle analysis method, which is the most informative method currently available. A brief outline of the most important developments follows. 

Determination of minor inorganic components in polymers such as polyesters is industrially relevant. It would appear that identification of Na-containing additives in a polymeric matrix by means of Na s-NMR is not a trivial matter in the presence of other... 

Inorganic pigments and lakes (organic dyes bonded to an inorganic support) can be recognized by the ratio of elements in their composition, making elemental analysis an important tool in their identification. EDS may facilitate an initial qualitative analysis, but quantitative analysis and the detection of trace elements are needed to identify the inorganic colorant components. Due to sample size restrictions, the methods that can be employed are limited. The techniques of inductively-coupled plasma mass spectrometry (ICP-MS), ICP-optical emission spectroscopy (ICP-OES), and laser ablation ICP-MS are described in the literature (56). 

Nonmetallic Inorganic Solids. This category includes many items of forensic importance ceramic and glasses naturally occurring substances such as building and insulation materials and soil components additives to papers, paints, explosives, drugs and many other materials. In contrast to metals, even the task of basic material identification often requires considerably more than the overall chemical analysis for these substances. 

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