Complexities in tetracycline analysis-chemistry, matrix extraction, cleanup, and liquid chromatography

The extraction and cleanup of commonly used tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) from sample matrix, and their subsequent determination via liquid chromatography can be problematic. Many manuscripts report on various challenges encountered when developing a method for tetracycline antibiotics determination. These complexities often result in less than perfect recoveries or chromatograms and are based on the underlying chemistry associated with tetracyclines. This review compiles, compares, and discusses the results and observations found in published methods, while focusing on chemical principles in order to increase the practicing chemist's understanding of TCs to aid him/her in developing useful analyses.