For the detection of tetraciclines in feathers, muscle and liver, an internal protocol was designed for in-house validation of two methods, through high performance liquid chromatography with tandem mass spectrometric (HPLC-MS/MS) techniques. This protocol was based on the recommendation of the decision 2002/657/EC from the European Community as well as the food and drug administration (FDA) VICHGL49. Limit of detection (LOD) was set at 20 μg kg-1 and the limit of quantification (LOQ) ranged from 21.5 to 24.2, 21.2 to 21.6, and 25.0 to 27.7 μg kg-1 in feahers, muscle and liver samples, respectively, for all analytes. The calibrations curves show a coefficient of determination (R2) above 0.98, 0.99 and 0.96 for feathers, muscle and liver samples, respectively. Analyte recovery ranged from 92 to 108%. In conclusion, these methods can be deemed accurate and reliable, and their validation is a fundamental step to be performed in depletion studies on these matrices.
Keywords:
in-house validation; HPLC-MS/MS; tetracyclines; feathers; broiler chickens