The Forensic Services Chemistry section of the National Forensic Science Technology Center (NFSTC) evaluated the handheld PHAZIR Near-Infrared (NIR) spectral analyzer manufactured by Polychromix, Inc., which is the type of field portable NIR spectrometer currently being used in a variety of industries to conduct fast, nondestructive, qualitative or quantitative analysis on solids, powders, and other materials.
The PHAZIR is a handheld NIR-based spectrometer that has a semi-rugged, ergonomic, and light-weight design. It uses a safe tungsten lamp as the excitation incident light source, which is focused on the unknown sample after the instrument's trigger has been activated by the user. When the sample is exposed to the electromagnetic radiation emitted from the light source, that radiation will be reflected, absorbed, and/or transmitted. The interaction between this radiation and the compound within the sample cause molecular excitation and vibrational energy changes during the analysis, the instrument collects digitized data of the corresponding overtones and combinations of vibrations that result in a spectra or unique chemical "fingerprint" of the material. After selecting the appropriate chemometric model for identification during the conformity portion of the evaluation, the PHAZIR was able to identify accurately with a "high" confidence level pure standard samples that contained controlled substances, cutting agents, or explosives. The sensitivity of the PHAZIR, using a medium confidence limit as the cut-off, was determined to be at a concentration of 30 percent for heroin, 20 percent for methamphetamine, and 40 percent for both cocaine base and cocaine HCl. The mobile laboratory environment had no noticeable effects on the PHAZIR's functioning. Although the PHAZIR does not require expertise in spectroscopy in order to develop a model for use, users may find advanced knowledge of spectroscopy to be required for model optimization and verification. 10 tables and images of the product evaluated