linguistic:voice_change, structural:expansion
Field analysis

Cocaine may be detected by law enforcement using the Scott reagent. The test can easily generate false positives for common substances and must be confirmed with a laboratory test.

Approximate cocaine purity can be determined using 1 mL 2% cupric sulfate pentahydrate in dilute HCl, 1 mL 2% potassium thiocyanate and 2 mL of chloroform. The shade of brown shown by the chloroform is proportional to the cocaine content. This test is not cross sensitive to heroin, methamphetamine, benzocaine, procaine and a number of other drugs but other chemicals could cause false positives.