title: Analysis of pharmaceuticals in fish using liquid chromatography-tandem mass spectrometry.
abstract: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening method has been developed targeting 23 pharmaceuticals and 2 metabolites with differing physicochemical properties in fish tissue. Reversed-phase separation of target compounds was achieved using a C18 column and a nonlinear gradient consisting of 0.1% (v/v) formic acid and methanol. Eluted analytes were introduced into the mass analyzer using positive or negative electrospray ionization, as appropriate. A variety of extraction solvents, differing in polarity, pH, or both, were investigated in order to assess recovery of target compounds from 1-g tissue homogenates. Among 10 solvents tested, a 1:1 mixture of 0.1 M aqueous acetic acid (pH 4) and methanol was identified as optimal, resulting in extraction recoveries for 24 of 25 compounds exceeding 60%. Tissue extracts were found to influence the LC-MS/MS response for several analytes. Consequently, matrix-matched calibration standards were employed to determine analyte concentrations in environmental samples. Statistically derived method detection limits were <6 ng/g for most analytes. The method was subsequently used to screen for target analytes in fish from an effluent-dominated stream. Diphenhydramine, diltiazem, carbamazepine, and norfluoxetine were detected in 11 of 11 environmental samples at concentrations ranging from 0.11 to 5.14 ng/g.
authors.affiliation: Department of Chemistry & Biochemistry, Baylor University, Waco, Texas 76798, USA.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Ramirez
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Mottaleb
authors.forename: Bryan W
authors.initials: BW
authors.lastname: Brooks
authors.forename: C Kevin
authors.initials: CK
authors.lastname: Chambliss
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis; D010473:Perciformes; D004364:Pharmaceutical Preparations / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D004364:Pharmaceutical Preparations