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Evaluation of the Thermo Scientific® FirstDefender RM™ Raman Spectrometer - Technology Evaluation

NCJ Number
234026
Author(s)
Hillary Markert; Joan Ring; Nicole Campbell; Kirk Grates
Date Published
July 2010
Length
49 pages
Annotation

The Forensic Services Chemistry Section of the National Forensic Science Technology Center (NFSTC) evaluated the Thermo Scientific FirstDefender RM, a hand-held Raman spectrometer that is currently used by law enforcement, border patrol officers, military personnel, and other first responders to chemically characterize unknown solids, liquids, and powders encountered in field environments.

Abstract

The evaluation determined that the strengths of the FirstDefender RM include being compact and lightweight (less than 2 pounds), does not destroy samples, requires very little sample preparation was accurate for most samples and produced reproducible results, and there are two available sampling modes that are similar in performance. Although the vial mode eliminates background interference, the point-and-shoot mode allows the user to analyze smaller amounts of samples. Areas for improvement are listed. This section of the report notes that the percentages listed in mixtures were misleading, since they did not represent the percentages of each result in the mixture, but rather the percentage of the sample spectrum that matched the library spectrum. In addition, the identification of phenethylamines such as MDMA, MDA, and MDEA was inaccurate. Further, matches were not accompanied by a correlation/confidence score. Limitations are also noted. The evaluation included accuracy and reproducibility assessment of conformity, mixture sensitivity, specificity, ruggedness, portability, and ease of use, including sample preparation and training requirements. The evaluation also briefly examined the FirstDefender RM's library-building capabilities. Appended tables

Date Published: July 1, 2010