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Microcrystalline Tests in Forensic Drug Analysis

Forensic Science

  1. Mathieu P. Elie,
  2. Leonie E. Elie

Published Online: 15 DEC 2009

DOI: 10.1002/9780470027318.a9102

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Elie, M. P. and Elie, L. E. 2009. Microcrystalline Tests in Forensic Drug Analysis. Encyclopedia of Analytical Chemistry. .

Author Information

  1. University of Lincoln, School of Natural and Applied Sciences, Lincoln, UK

Publication History

  1. Published Online: 15 DEC 2009


Drug detection in the forensic context requires numerous analytical techniques. Depending on locally adopted standard procedures, different techniques are used for screening solid samples for potential illicit substances (e.g. Fourier transform infrared spectroscopy (FTIR)). A sample suspected of containing prohibited material passes through another layer of techniques to confirm that the illegal substance is present and to identify it (e.g. liquid/gas chromatography). Finally, the drug is systematically quantified (e.g. mass spectrometry). Microcrystalline tests fall within the second step of this analytical process. They are low cost because of the minute amount of reagents used and the simplicity of the instrumentation and consumables required to perform the analysis. They offer all the features required by a good confirmation technique while being very fast to administer and interpret, although they do not offer quantification capabilities.

Microcrystalline tests are chemical tests resulting in the formation of unique microcrystals for a given substance when combined with a specific reagent. Microcrystals are observed under a microscope and micrographs or microvideos constitute the results of the test.

Thanks to the chemical mechanism by which microcrystals develop, microcrystalline tests can be applied to molecules of various sizes, shapes, charges, and with different functional groups, and can naturally distinguish between enantiomers.