1. What are the advantages of color and TLC tests? Under what circumstances might a color test be preferred over TLC ?
2. TLC data have been used as evidence in court cases. What do you think of this practice ?
3. How does one determine that one has a false positive result ?
4. What difficulties can one encounter when conducting a microcrystal examination ?
5. When treated with Duquenois reagent, the extract of a suspect substance turned gray. How could you tell whether the substance contained marijuana, tobacco, or tea leaves ?