Determination of β-blockers and β₂-agonists in sewage by solid-phase extraction and liquid chromatography–tandem mass spectrometry

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• 作者：Hing-Biu Lee ; Kurtis Sarafin ; Thomas E. Peart
• 关键词：β ; -Blockers ; β ; ₂-Agonists ; Sewage ; Solid-phase extraction ; LC– ; MS/MS
• 刊名：Journal of Chromatography A
• 出版年：2007
• 出版时间：4 May 2007
• 年：2007
• 卷：1148
• 期：2
• 页码：158-167
• 全文大小：962 K

文摘

A method using solid-phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) has been developed for the determination of 12 β-blockers and β₂-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 °C in the dark. Many β-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 β-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.