Infrared Analysis for the Busy Crime Laboratory -- Getting the Most Out of Illicit Drug Analysis Using FT-IR and GC-MS

摘要

According to the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG), techniques with the highest discriminating power should preferentially be used for forensic identification of seized drugs. Table I shows the analytical technique categories listed in order of decreasing discriminating power from A to C. SWGDRUG recommends at minimum that when a Category A technique is used, at least one other technique of any category must also be used. In practice, many drug labs choose GC-MS since this addresses the recommendation and they get credit for the two techniques -- MS (Category A) & GC (Category B). However, this recommendation is a minimum and many labs are finding that GC-MS is not always the best choice for the particular sample they are analyzing. Infrared spectroscopy can do things GC-MS can't, such as analyzing drugs in salt form and uniquely identifying certain stereoisomers. It is also an excellent rapid-screening tool. In fact, in most federal labs, infrared analysis is a requirement.