Abstract
The concentration of hydrochloric acid and potassium iodide in Dragendorff's reagent was examined in order to obtain high sensitivity in the detection of alkaloids. As the samples, caffeine, morphine, procaine, cocaine, methamphetamine, ephedrine, chloroephedrine, methylephedrine, codeine, and dihydrocodeine were used. The optimum concentrations of hydrochloric acid and potassium iodide were determined by measuring the unreacted amount of bismuth in the reaction mixture of an alkaloid and the Dragendorff's reagent containing a definite amount of these two components when using caffeine, cocaine, procaine, codeine, and dihydrocodeine. For other alkaloids, however, the optimum concentration of the two components could not be determined.
