These two articles describe gunshot residue analysis by micellar electrokinetic capillary electrophoresis and assess its application to casework.
Micellar electrokinetic capillary electrophoresis (MECE) has been used to examine characteristic organic gunpowder compounds, including nitroglycerin, diphenylamine, ethylcentralite, and others. This study attempts to provide data and reference information to assess MECE for use in forensic gunshot residue (GSR) casework. It describes sample collection and preparation, detection limits, interferences, occurrences of characteristic organic gunpowder compounds (COGC) in the general population resulting from environmental or occupational exposure, and the characteristic composition of some common ammunitions. The study generated a database of COGC in selected commercial gunpowder. The study demonstrates the value of MECE analysis for organic GSR (O-GSR). Because MECE analysis can identify COGC, it is possible to generate more information than is possible with inorganic gunshot residue analysis. The significance of detecting O-GSR on a sample is magnified by the finding of no false positive results in any of the experiments conducted for this study. MECE detection limits for COGC provide for the ability to obtain quantitative analysis on samples smaller than an individual grain of gunpowder. The study describes organic GSR persistence, environmental exposure effects, comparison of MECE analysis results to scanning electron microscopy (SEM) results, and casework using both analytic methods. Tables, figures, references