One way to identify use of methamphetamine in a population is tomonitor the waste water. Methamphetamine is excreted from the bodyup to 23% unchanged and can cause unintended environmentalexposures. It has been detected in the sewage of all major cities,even after sewage treatment. Methamphetamine is organic base with apKaof 10.0 [12].
a. Many sewage treatment facilities induce pH ranges from pH 5to pH 10 to encourage degradation. Is methamphetamine charged atthese extremes? Also, circle and name the functional group(s)predominately responsible for the pKa. Please provide yourreasoning.
b. Methamphetamine is excreted in urine as a cation. Assuming itenters the environment as a cation, which of the four environmentalcompartments would you expect to find methamphetamine? Use chemicalproperties and environmental properties to justify your reasoning.(Hint: there are potentially two compartments.)
c. Assuming methamphetamine enters the environment as a cationthrough urine, what environmental properties determine whichenvironmental compartment methamphetamine will be in?
d. Roughly three to six pounds of toxic waste is produced foreach pound of
methamphetamine produced. Vapors created during production alsocause further
environmental contamination, depositing the un-charged drug onsurfaces near the
production site. The log Kow of methamphetamine is 2.07. What isthe ratio of
methamphetamine in octanol:water?
i. What does this imply about BCF?
ii. What does it imply about K
d
?
iii. Also, what does all of this mean when we are talking aboutenvironmental
transport and potential persistence of methamphetamine in theenvironment?
