ABSTRACT
A method was optimised and validated for simultaneous monitoring of several drugs of different classes of antibiotics such as quinolones (oxilinic acid and flumequine), tetracyclines (oxytetracycline), sulfonamides (sulfadiazine) and trimethoprim in fish muscle and skin. The method is based on solid-liquid extraction without further sample clean up followed by liquid chromatography-mass spectrometry (LC-MS) determination with electrospray ion source (ESI) in positive mode. The limits of quantification (LOQs) were lower than 20 microg/kg for all compounds and repeatability, expressed as relative standard deviations (RSD), were lower than 15%. Therefore, the LC-MS method was successfully applied for the quantitative determination of antibiotics in gilthead sea bream muscle and skin and oxytetracycline in medicated fishes.
Subject(s)
Anti-Bacterial Agents/analysis , Drug Residues/analysis , Fish Diseases/drug therapy , Muscles/chemistry , Sea Bream/metabolism , Tetracyclines/analysis , Veterinary Drugs/analysis , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Chromatography, High Pressure Liquid/methods , Drug Residues/chemistry , Fish Diseases/metabolism , Fishes/metabolism , Molecular Structure , Oxytetracycline/analysis , Quinolones/analysis , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , Solid Phase Extraction , Spectrometry, Mass, Electrospray Ionization/methods , Sulfonamides/analysis , Tandem Mass Spectrometry/methods , Trimethoprim/analysis , Veterinary Drugs/chemistry , Veterinary Drugs/therapeutic useABSTRACT
The distribution of gamma-linolenic acid (GLA) was studied in the seed oil of six Cape Verdian Boraginaceae. The GLA ranges from trace levels in the three Heliotropum surveyed to 22.2% on saponifiable oil in Echium stenosiphon. All Echium species had GLA percentages in their seed oil around 20%. Echium seeds yield saponifiable oil from 15.8% (E. stenosiphon) to 17.3% (E. hypertropicum).
