Solvent Front Position Extraction Procedure for Preparation of Biological Samples with Coccidiostats for Liquid Chromatography-Tandem Mass Spectrometry Determination

摘要

Coccidiostats are a group of drugs used for the treatment of coccidiosis. This disease is common among animals for slaughter. Residues of the mentioned drugs can be potentially harmful for human health, so there is a constant need for cheap and quick method for their determination. A novel sample preparation technique, solvent front position extraction (SFPE), for liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for such a purpose. In the SFPE procedure, the adsorbent layer of a chromatographic plate is used for purification and separation of substances of interest from matrix components. After applying the SFPE technique, solutes and the internal standard are not only separated from unwanted components, but also focused and evenly distributed in the zone located at the solvent front position. From such a zone, the substances can be directly transferred from thin-layer chromatography (TLC) plate to LC-MS instrument using the TLC-MS Interface. Focusing the substances of interest in a narrow zone improves the sensitivity of an assay, while the homogeneity of these zones guarantees their accurate quantification, even if only a part of the substance zone undergoes extraction using a TLC-MS Interface. The SFPE procedure is especially recommended for samples with high viscosity or/and with large amounts of contaminants and enables cleaning a final sample solution from matrix components, showing lower and stronger retention than the solutes of interest. In this work, the application of SFPE procedure for separation of the substances of interest from two biological matrices (bovine serum and animal feed) is presented. The results are promising and allow their application for further research of these compounds.