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PHARMACEUTICALS IN WASTE STREAMS AND SURFACE WATERS OF THE COLORADO RIVER BASIN
Citation:
Sanchez, C., T. L. JONES-LEPP, D. Wilson, AND D. Alvarez. PHARMACEUTICALS IN WASTE STREAMS AND SURFACE WATERS OF THE COLORADO RIVER BASIN. Presented at Lake Mead Science Symposium, Las Vegas, NV, January 13 - 14, 2009.
Impact/Purpose:
Presentation
Description:
A number of pharmaceuticals have been detected in surface waters across the United States. The objective of this study was to evaluate the presence of selected pharmaceuticals (macrolidic antibiotics and pseudoephedrine) and illicit drugs (methamphetamine and Ecstasy) in surface waters of the Colorado River basin. Grab samples were collected spatially and temporally from waste stream tributaries and receiving surface waters within the basin in Colorado, Utah, Nevada, Arizona, and California. At selected locations we also used time-weighted polar organic chemical integrative samplers (POCIS). Grab samples were prepared for analysis using an automated extractor (AutoTrace, Caliper Life Sciences) with Oasis MCX cartridges (Waters Corp.), subsequently extracted with 5- mLs of 80:20:1 methyl tertbutyl ether/methanol/acetic acid, and 5 mLs 99:1 methanol/acetic acid, and reduced to 0.5 mL using an automated evaporator (TurboVap-Zymark, Caliper Life Sciences). Recovery of the analytes from the POCIS sorbent was achieved by transferring the sorbents into glass gravity- flow chromatography columns fitted with glass wool plugs and stopcocks. Methanol was used to elute the pharmaceuticals from the sorbent. All extracts were analyzed with a Varian 500MS ion trap mass spectrometer by performing real-time mass analyses of LC eluents. One or more of the pharmaceuticals and/or illicit drugs evaluated were found in urban waste streams at concentrations sometimes exceeding 500 ng/L. However, amounts found in the main surface water channels, including the Colorado River, were always below 10 ng/L and most frequently below detection.