Fingerprint composition and aging: A literature review.

Fingerprints have a key role in criminal investigations and are the most commonly used form of evidence worldwide. Significant gaps remain however, in the understanding of fingerprint chemistry, including enhancement reaction mechanisms and the effect of environmental variables and time on composition. Determining the age of a fingerprint is also a relatively unexplored area.

Characterization of the bulk properties of pharmaceutical solids using nonlinear optics--a review.

With the development of stable, compact and reliable pulsed laser sources the field of characterizing materials through their nonlinear optical response has bloomed. Second harmonic generation by non-centrosymmetric crystal structures has provided a new spectroscopic tool of potentially great utility in the pharmaceutical field. The nonlinear optical response of various materials provides a very sensitive technique for the characterization of pharmaceutically interesting bulk compounds and dispersions, and determining their concentrations.

Towards characterization and identification of solid state pharmaceutical mixtures through second harmonic generation.

In this paper, we report improvements to a previously developed method based on optical nonlinearity for characterizing polymorphism and concentration of pharmaceuticals in powdered and tablet form. An apparatus that measures the nonlinear optical response of a sample through second harmonic generation (SHG) is described. The response of several enalapril maleate-polyvinylpyrrolidone (PVP) tablets was measured, the results of which were used to determine the concentration of the drug.