title: Determination of beta-blockers and beta2-agonists in sewage by solid-phase extraction and liquid chromatography-tandem mass spectrometry.
abstract: A method using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of 12 beta-blockers and beta(2)-agonists in wastewater samples. Extraction of the drugs was effected by an Oasis MCX cartridge with a strong cation resin adsorbent. Matrix coextractives were removed from the SPE cartridge by methanol prior to the elution of the drugs with a mixture of dichloromethane, 2-propranol, and ammonium hydroxide. The extract was analyzed by LC-MS/MS with electrospray ionization operating in the positive mode. Recovery of the 12 compounds was in most cases better than 85% at the fortification levels of 500 and 50 ng/L, with standard deviations between 3 and 7%. Based on a concentration factor of 250, the method detection limits ranged from 6 to 11 ng/L for the target compounds. No degradation of these drugs in spiked sewage effluent samples was observed over a storage period of 7 days at 4 degrees C in the dark. Many beta-blockers were detected in the 14 wastewater samples collected from seven Canadian sewage treatment plants; those occurring at the highest concentrations were atenolol, acebutolol, sotalol, and metroprolol, with overall median concentrations of 1370, 339, 282, and 257 ng/L, respectively. However, there was only a small decrease in the median concentrations of these beta-blockers between the primary and final effluent, suggesting that these drugs are not easily removed by the sewage treatment processes. As a result of selective extraction and effective removal of coextractives, no matrix effect was observed for the samples during LC-MS/MS analyses.
authors.affiliation: Aquatic Ecosystem Protection Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada. bill.lee@ec.gc.ca
authors.forename: Hing-Biu
authors.initials: HB
authors.lastname: Lee
authors.forename: Kurtis
authors.initials: K
authors.lastname: Sarafin
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Peart
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000032:analysis* / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D015394:Molecular Structure; D015203:Reproducibility of Results; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000319:Adrenergic beta-Antagonists; D012722:Sewage