Comparison of Four Commercially Available Portable Raman Spectrometers

• NCJ Number: 242229
• Author(s): Hillary Markert, M.F.S.; Joan Ring, M.S.; Nicole Campbell, B.S.; Kirk Grates, B.A.
• Date Published: January 2011
• Length: 8 pages
• Grant Number(s): 2007-MU-BX-K008
• Agencies: NIJ-Sponsored
• Publication Type: Test/Measurement; Research (Applied/Empirical); Report (Grant Sponsored)
• Award: Forensic Technology Center of Excellence

Annotation

In order to assist prospective users in determining which portable Raman device may best suit their agency's needs, this report by the National Forensic Science Technology Center presents results from its evaluations of four commercially available field-portable Ramon spectrometers.

Abstract

Field-portable Raman spectrometers enable first responders to perform non-destructive analyses on unknown bulk powders and liquids that contain compounds such as illicit and pharmaceutical drugs, explosives, ignitable liquids, oxidizers, industrial chemicals, and common household materials. The devices evaluated were the ICx Technologies Fido Verdict, the DeltaNu ReporterR, the Thermo Scientific FirstDefender RM, and the Smiths Detection RespondeR RCI. Overall, the FirstDefender RM performed with the most reproducibility between trials, followed by the Verdict, ReporteR, and RespondeR RCI; however, a potential buyer should factor in the requirements of reproducibility used in the evaluation chart; e.g., three negative or three incorrect results for an instrument were still considered reproducible, while correct, but different results (e.g., cocaine and caffeine) across trials, however, were not considered reproducible. The mixture feature is available only on the FirstDefender RM, which allows for single match results and matches across the trials in a mixture sample to be counted as reproducible. Each spectrometer was tested separately, using the same standardized, systematic evaluation scheme to assess individual strengths, areas for improvement, limitations, graphical user interfaces, and safety issues, as well as the entire chemical characterization process involved from sample introduction through result output. Representative samples of controlled and non-controlled drugs (standards and adjudicated case samples), drug diluents, ignitable liquids, explosives, explosive precursors, and common household and laboratory compounds were used to assess each unit for conformity, mixture sensitivity, specificity, portability, and ruggedness. Accuracy and reproducibility were examined for each dataset. 4 figures and 6 references