To determine if a white powder found at the crime scene or in the possession of a suspect contains an illicit drug.

The sample is a mixture of two white solids. One solid is a simulated illicit drug (e.g. aspirin); the other solid is a cutting agent (e.g. starch). Students are told there are three possible "drugs" -- "cocaine" (caffeine), "heroin" (acetaminophen), "PCP" (aspirin). According to government reports, street drugs are on average 50% to 80% active ingredient; prepare the samples similarly.

White solids simulating drugs; white solids as cutting agents (glucose, starch, quinine)

Standard Reference Material

None

FT-infrared spectrophotometry; KBr pellet

FT-infrared spectrophotometer; KBr pellet-making materials

For instructor (detailed); For student (brief)

FT-infrared spectra of simulated drugs (e.g. "cocaine") and cutting agents (e.g. glucose).

FT-Raman Spectrophotometery

Procedure

FT-Raman spectra of the same (e.g. "cocaine"). These spectra show much more noise than the infrared spectra. Of course, lower resolution and more scans would provide better signal-to-noise results.