Determination of beta-blockers and beta2-agonists in sewage by solid-phase extraction and liquid chromatography-tandem mass spectrometry.
J Chromatogr A
; 1148(2): 158-67, 2007 May 04.
Article
em En
| MEDLINE
| ID: mdl-17408682
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.
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Bases de dados:
MEDLINE
Assunto principal:
Esgotos
/
Cromatografia Líquida
/
Antagonistas Adrenérgicos beta
/
Espectrometria de Massas em Tandem
/
Extração em Fase Sólida
Idioma:
En
Revista:
J Chromatogr A
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Canadá