Oxidative Transformation of Controlled Substances by Manganese Dioxide

Figure 1

Oxidation of the four controlled substances by MnO₂: (a) ketamine at pH 5, (b) methamphetamine at pH 5, (c) morphine, and (d) codeine (compound concentration = 100 μg/L, ionic strength = 10 mM).

(a)

(b)

(c)

(d)