Desarrollo de nuevos métodos para el análisis de doxiciclina en residuos orgánicos por HPLC

Two simple fast methods have been developed to analyze doxicycline in surpluses of pigs by liquid chromatography. Sample preparation consists of a simple extraction with acidic water followed by a clean-up step carried out by solid phase extraction cartridges. Two inverse phase columns, a high speed column and a microbore, were evaluated for the chromatographic determination. A mobile phase of acetonitrile and water (0.1% HCOOH) was employed in all cases, gradient elution for the first column and an isocratic elution mode with the second. Detection was performed by mass spectroscopy with electrospray in positive mode. Recovery is over 70% and detection limits are 250 pg/Kg, when the microbore column is employed, and 500 pg/Kg, using the high speed one. By means of a MS-MS detector, detection limit is 10 μg/Kg.