Forensic chemists are faced with the challenge of analyzing a multitude of sample types to identify controlled substances and pharmaceuticals. Law enforcement depends on a laboratory’s ability to identify not only the major components of the samples, but also relevant compounds present at lower levels. These samples can range from an unidentified white powder or botanical material to tablets, syringes, or charred pipe residues. Typically, these analyses are performed by full scan GC/MS with library search reports generated by database searching. Because the evidence obtained by law enforcement can encompass an ever widening variety of analytes including closely related compounds such as isomers and possible analogs, greater attention to detail is required in the analysis. The new novel psychoactive substances (NPS) and synthetic cannabinoids that have hit the streets contain many new isomers and analogs that are not readily differentiated by routine searching methods. This system uses the following enhancements to increase the efficiency of analysis. Hydrogen is used as carrier gas to reduce operating costs. Retention time locking (RTL) is used to maintain precise retention time matching between multiple systems and the database. Backflush provides a mechanism to remove nonvolatile compounds by flow switching and redirecting them out the split vent. Finally, deconvolution reporting software (DRS) is used to identify drugs, even when present in complex mixtures or at trace levels. Results from the new system are compared to a typical helium system currently used for criminalistics analysis.
Publication number: 5991-4536EN.pdf
Publication Date: June 15, 2014