Analysis of fluoroquinolones in animal feeds by liquid chromatography with fluorescence detection.

An analytical method for the analysis of six fluoroquinolones (FQs) in animal feeds was developed. The sample treatment consists of a simple and rapid extraction of the analytes by manual shaking with an acetonitrile-water mixture containing hydrochloric acid without further sample cleanup. Matrix effects were minimized by diluting the extract with water.

Analysis of macrolide antibiotics in river water by solid-phase extraction and liquid chromatography-mass spectrometry.

A liquid chromatography-mass spectrometry (LC-MS) method was developed for the determination of five macrolides in natural water samples, using kitasamycin as surrogate. The macrolides were extracted from water samples using Oasis HLB cartridges. Pre-concentration factors up to 250 were obtained.

Determination of triorganotin species in water samples by liquid chromatography-electrospray-mass spectrometry.

Liquid chromatography coupled to electrospray-mass spectrometry (LC-ES-MS) with positive ion detection was evaluated for the determination of tributyltin and triphenyltin in water samples using tripropyltin as internal standard. The separation was performed in the isocratic mode on a silica-based C18 column with a mobile phase containing 0.02% trifluoroacetic acid in acetonitrile-water (50:50, v/v).