Rapid Analysis of Tetracycline Antibiotics by.pdf

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Commun. Mass Spectrom. 13, 1744–1754 (1999) Rapid Analysis of Tetracycline Antibiotics by Combined Solid Phase Microextraction/High Performance Liquid Chromatography/Mass Spectrometry 1 1 2 Chris M. Lock *, Luke Chen and Dietrich A. Volmer 1Institute for Marine Biosciences, National Research Council, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1 Canada 2Merck KGaA, Analytical Research (ZD-A/ZFA), Frankfurter Str. 250, D-64271 Darmstadt, Germany The technique of solid phase microextraction (SPME) combined on-line with high performance liquid chromatography/mass spectrometry (HPLC/MS) has been applied to the analysis of seven tetracycline analogues. Rapid baseline separation was achieved in under 5 min using a short 3 m RP-18e cartridge column. Optimisation of the SPME procedure is described including choice of extracting fibre and modification of the sample by heating or salting out of the analytes. Detection limits of 4–40 ng/mL were obtained for the various analogues from extracted aqueous samples and absolute amounts of analyte extracted by the method determined using external calibration. To demonstrate the applicability of the technique for real samples the extraction of tetracycline from milk is described. Copyright 1999 John Wiley Sons, Ltd. Received 18 May 1999; Revised 7 July 1999; Accepted 9 July 1999 The tetracycline group of antibacterial agents has become sample pre-treatment with ethylenediaminetetraacetic acid widely used in veterinary practice and animal rearing for (EDTA).12 both therapeutic and p