Determination of tetracyclines in pig and other meat samples using liquid chromatography coupled with diode array and tandem mass spectrometric detectors.

Two high performance liquid chromatographic methods (HPLC-DAD and LC-MS/MS) were developed to analyze tetracycline (TC) residues in pig meat (pork) samples. The method involved a sample preparation using a solid-liquid extraction (SLE) by McIlvaine buffer, followed by a solid-phase extraction (SPE) clean-up using Strata-XL cartridges. The developed sample clean-up resulted in a selective chromatogram in the HPLC-DAD separation and a reduced matrix effect (ME) in LC-MS/MS analysis. Moreover, HPLC columns packed with core-shell particles were tested for separation, which further enhanced the sensitivity and the selectivity of determinations. The validation of the methods for pig samples was carried out according to European Union 2002/657/EC decision. In addition, validation was also performed for bovine, chicken, and turkey meat samples using HPLC-DAD method. The performance characteristics of determinations were evaluated with both spiked and incurred samples, and were systematically compared. LC-MS/MS technique was found to be more accurate for spiked samples; however, HPLC-DAD method resulted in more reliable concentrations for incurred samples.