Analysis of pharmaceuticals in fish using liquid chromatography-tandem mass spectrometry

Anal Chem. 2007 Apr 15;79(8):3155-63. doi: 10.1021/ac062215i. Epub 2007 Mar 10.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatography, Liquid / methods*
  • Drug Residues / analysis
  • Perciformes*
  • Pharmaceutical Preparations / analysis*
  • Tandem Mass Spectrometry / methods*

Substances

  • Pharmaceutical Preparations