A Comparison of Portable Infrared Spectrometers, Portable Raman Spectrometers, and Color-Based Field Tests for the On-Scene Analysis of Cocaine

摘要

The majority of inmates in the United States are incarcerated for drug-related offenses. It is important that the technology used to test for controlled substances be accurate and reliable. For on-scene presumptive testing, color-based field tests are commonly employed. Numerous cases have been discovered where positive color-based field tests were later proven to be false positives via confirmatory laboratory testing. Portable infrared (IR) and Raman spectroscopy are capable of providing accurate and reliable identifications at the scene, but are not generally utilized for this purpose. This research evaluated important performance characteristics of these methods to determine which is best for conducting on-scene testing of cocaine HCl. This research concluded that although portable spectrometers require a large initial financial investment, their high performance characteristics (such as ease of use, rapid analysis, non-destructive capability, acceptable limit of detection, and minimal false positives and negatives) make them a superior tool to the color-based field tests for the on-scene presumptive analysis of cocaine HCl. Portable IR spectroscopy was determined to be better than portable Raman because of the lower limit of detection, less severe adulterant interferences, and Raman fluorescence of common drugs (such as heroin or additives).