Analysis of amphetamine and methamphetamine in municipal wastewater influent and effluent using weak cation‐exchange SPE and LC‐MS/MS

Amphetamine and methamphetamine are emerging contaminants—those for which no regulations currently require monitoring or public reporting of their presence in our water supply. In this research, a protocol for weak cation‐exchange (WCX) SPE coupled with LC‐MS/MS was developed for determination of emerging contaminants amphetamine and methamphetamine in a complex wastewater matrix. Gradient LC parameters were adjusted to yield baseline separation of methamphetamine from other contaminants. Methamphetamine‐D5 was used as the internal standard (IS) to compensate for sample loss during SPE and for signal loss during MS (matrix effects). Recoveries were 102.1 ± 7.9% and 99.4 ± 4.0% for amphetamine and methamphetamine, respectively, using WCX sorbent. Notably, methamphetamine was determined to be present in wastewater influent at each sampling date tested. Amphetamine was present in wastewater influent on two of four sampling dates. Amphetamine concentrations ranged from undetectable to 86.4 ng/L in influent, but it was undetectable in wastewater effluent. Methamphetamine was detected in influent at concentrations ranging from 27.0–60.3 ng/L. Methamphetamine concentration was reduced but incompletely removed at this facility. Although absent in one post‐UV effluent sample, concentrations of methamphetamine ranged from 10.8–14.8 ng/L.