II. DRUGS OF ABUSE

3. Cocaine

1. What is the name of the plant (genus, species) in which cocaine is a naturally occurring alkaloid?
2. To what do the terms, “cocaine base,” “crack,” "freebase" and “rock” refer?
3. Describe the chemical process to produce crack or freebase out of cocaine powder.
4. How is cocaine hydrochloride used?
5. How is cocaine base used?
6. Contrast the physical appearance of cocaine hydrochloride with that of cocaine base.
7. What are common adulterants and diluents found in illicit cocaine samples?
8. What are some degradation products that can result from cocaine?
9. Cocaine has four enantiomeric/diastereomeric forms. Name them.
10. Does your jurisdiction control the base form of cocaine, differently than it controls cocaine salt?
11. Does your jurisdiction impose enhancements to penalties for quantities of cocaine?
12. What countries are typical sources for the coca plant?
13. In what form is cocaine typically transported?
14. Describe the process of isolating cocaine from the coca plant.
15. In general terms, how is cocaine hydrochloride converted into cocaine base?
16. How does the salt form of cocaine affect color tests, solubilities and extraction procedures?
17. Does EI-GCMS differentiate among the various diastereoisomers of cocaine? If so, which ion fragments or relative ion fragment ratios are particularly discriminating?
18. Under what circumstances would GCMS be a preferred analytical technique for the identification of cocaine?
19. What are the diastereomers and enantiomers of cocaine? Can they be distinguished with FTIR and GC/MS?
20. What are some other alkaloids from the cocaine plant, besides cocaine, that commonly appear in GCMS analyses?
21. Does conversion of the salt form of cocaine into the base form of cocaine constitute manufacturing?
22. Contrast the application of Co(SCN) 2 to cocaine hydrocholoride and to cocaine base?
23. Will Co(SCN) 2 produce similar results with benzocaine, lidocaine, and procaine, as it does with cocaine?
24. Will infrared spectrometry distinguish cocaine hydrochloride from cocaine base? From pseudococaine hydrochloride?
25. Explain why the presence of cis- and trans-cinnamoylcocaine may be problematic when quantitation of cocaine is performed by UV spectrophotometry.
26. What color tests are typically used for the presumptive identification of cocaine?
27. Suggest an extraction scheme to isolate suspected cocaine from shampoo, in preparation for subsequent GCMS injection
28. How is cocaine hydrochloride converted into “crack”?
29. How is cocaine hydrochloride converted into “rock cocaine”?
30. What common feature does “caine” refer to in the terms cocaine, benzocaine, lidocaine and procaine?
31. True or false?: Placing cocaine hydrochloride in a basic aqueous solution, will cause it to be mostly uncharged and more soluble in nonpolar (e.g. organic) solvents.
32. True or false?: Placing cocaine hydrochloride in an acidic aqueous solution, will cause it to be mostly charged and more soluble in polar (e.g. aqueous) solvents.
33. Why would FTIR be considered a preferred analytical technique for the identification of cocaine?
34. Since the cocaine molecule contains two carbonyl groups, would you expect the IR of the carbonyl region to have one or two absorption peaks? Why?
35. The Merck Index states that the specific rotation [α] D of cocaine hydrochloride is -72 at c=2 in an aqueous solution at pH 4.5.
• At what wavelength was the measurement made?
• What concentration is represented by c=2?
• Is the temperature given at which the polarimetric measurement was made?
• Given the information listed in the Merck Index, calculate the actual rotation α you would expect to observe on the polarimeter if the aqueous cocaine hydrochloride solution was run at the specified concentration in a 1 decimeter cell.
• Although specific rotation measurements are reported in either degrees or without units, determine the actual dimensions (units) for specific rotation [α].
36. What are other materials that can contain cocaine?
37. What does the presence of these other forms indicate?
38. What street drug term refers to a mixture of cocaine and heroin?
39. Can cocaine hydrochloride be effectively smoked in a pipe? Explain.
40. Is cocaine easily detectable in residue left in a pipe after smoking?
41. What is the melting point of cocaine base?
42. What is the melting point of cocaine hydrochloride?
43. How many asymmetrical centers are present in the cocaine molecule?
44. How many stereoisomers does this number of asymmetric centers predict?
45. How many diastereoisomeric pairs of cocaine are observed?
46. Does your analytical protocol require that “cocaine base” be distinguished from salt forms of cocaine?
47. What are the physical differences between cocaine HCl and cocaine base?
48. Describe the differences in use between cocaine HCl and cocaine base. Why would one be used over the other? What form would typically have more 'cuts'? Why?
49. Does cocaine have any legitimate medicinal use?
50. Draw the structures of the four cocaine isomers and show the equatorial/axial relationship of the carbomethoxy- group and the benzoyloxy- group for each isomer.
51. What are four properties (chemical & physiological) of cocaine base (aka smokable cocaine) that have contributed to its popularity?
52. A sample submitted to you for analysis (labeled as suspected cocaine, and described as "rock-like substance") is a thick brown liquid. Provide an explanation for what happened.
53. How does the salt form of cocaine affect the administration of cocaine in the body?
54. If procaine hydrochloride is present with cocaine hydrochloride when it is converted into cocaine base, is the procaine removed from the product or does it form the free base form of procaine?
55. Discuss the “cocaine isomer defense.”
56. How is the Scott Test more selective than using aqueous Co(SCN) 2 alone?
57. Describe an analytical protocol sufficient for conclusive qualitative identification of cocaine.
58. Is this protocol also adequate for reporting a conclusive qualitative identification of “cocaine base”?
59. What are the taxonomical names (genus, species) for the plants that are used to produce cocaine?
60. When and how was the “isomer problem” for cocaine prosecutions resolved?