R4 AM Occurrence and Fate of Pharmaceutical and Other Emerging Wastewater Contaminants in Aquatic Systems
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in Ballroom 4

(SCH-1117-818377) Determination of antidepressant pharmaceuticals and their degradates in municipal wastewater.

Schultz, Melissa¹, Kinney, Chad², Phillips, Patrick ³, Furlong, Edward ¹, ¹ U.S. Geological Survey, Denver, CO, USA² Eastern Washington University, Cheney, WA, USA³ U.S. Geological Survey, Troy, NY, USA

ABSTRACT- Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed antidepressant pharmaceuticals that include fluoxetine (Prozac¹), sertraline (Zoloft¹), and paroxetine (Paxil¹). Despite 20 years of widespread use, few analytical methods exist to detect SSRIs in environmental matrixes, thus little is known about their distribution and fate in the environment. Previous studies found that fish populations residing in a municipal effluent-dominated stream contained concentrations of fluoxetine, sertraline, norfluoxetine, and desmethylsertraline in all muscle, liver, and brain tissues examined, suggesting that wastewater effluent is one of the possible routes for introducing antidepressant pharmaceuticals into aquatic environments. A quantitative method was developed for the analysis of SSRIs and selected degradates in municipal wastewater. This method also was extended and adapted to determine other antidepressant drugs and their degradates that are prescribed when SSRIs are not effective, including bupropion (Wellbutrin¹), venlafaxine (Effexor¹), and duloxetine (Cymbalta¹). Samples were concentrated by using solid-phase extraction, and the extracts were analyzed by a liquid chromatograph coupled to a tandem mass spectrometer by means of an electrospray interface (LC ESI-MS/MS). Quantitation was based on the ratio of the peak area of the analyte to that of the internal standard, sertraline-d₃. Method quantitation limits were approximately 1 ng/L. Preliminary analyses of antidepressant pharmaceuticals and their degradates in New York and Washington state municipal wastewater samples showed individual levels ranging from 1 ng/L to 40 g/L and 1 ng/L to 160 ng/L, respectively. The validated method was applied to a representative set of municipal wastewater samples collected from plants nationwide. ¹Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Key words: antidepressants, pharmaceuticals, SSRI, wastewater contaminants