Desorption-ionization on silicon mass spectrometry: an application in forensics

Desorption-ionization on silicon (DIOS) is a new, matrix-free laser desorpt ion mass spectrometry approach that allows for the direct identification of low molecular weight compounds in the presence of potentially interfering compounds. The porous silicon surfaces provide a scaffold for trapping anal yte molecules, and are readily adaptable to commercial time-of-flight instr uments. As an example of its utility in forensic cases, DIOS mass spectrome try was used to distinguish between similar synthetic polymers and identify specific polymers from complex biological media. Despite the absence of ma trix, specific low molecular weight polymers were rapidly identified withou t any fragmentation. This method was applied to the rapid identification of ethoxylate polymers during a criminal investigation. (C) 2001 Elsevier Sci ence B.V. All rights reserved.