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E. Patyra, E. Kowalczyk, A. Grelik, M. Przeniosło-Siwczyńska and K. Kwiatek

Abstract

A liquid chromatography – diode array detector (HPLC-DAD) procedure has been developed for the determination of oxytetracycline (OTC), tetracycline (TC), chlorotetracycline (CTC), doxycycline (DC), enrofloxacin (ENR), ciprofloxacin (CIP), sarafloxacin (SAR) and flumequine (FLU) residues in animal drinking water. This method was applied to animal drinking water. Solid-phase extraction (SPE) clean-up on an Oasis HLB cartridge allowed an extract suitable for liquid chromatographic analysis to be obtained. Chromatographic separation was carried out on a C18 analytical column, using gradient elution with 0.1% trifluoroacetic acid – acetonitrile – methanol at 30°C. The flow-rate was 0.7 mL/min and the eluate was analysed at 330 nm. The whole procedure was evaluated according to the requirements of the Commission Decision 2002/657/EC, determining specificity, decision limit (CCα), detection capacity (CCβ), limit of detection (LOD), limit of quantification (LOQ), precision and accuracy during validation of the method. The recoveries of TCs and FQs from spiked samples at the levels of 10, 100 and 1000 μg/L were higher than 82%. The developed method based on HPLC-DAD has been applied for the determination of four tetracyclines and four fluoroquinolones in animal drinking water samples.

Open access

E. Kowalczyk, E. Patyra, A. Grelik and K. Kwiatek

Abstract

A high performance liquid chromatography combined with fluorescence detection (HPLC-FLD) method was developed for determination of five ergot alkaloids (EA): ergometrine, ergotamine, ergocornine, ergocrypine and ergocristine in animal feedingstuffs. The method was based on the application of QuEChERS salts for extraction and modified QuEChERS dispersive SPE for the cleanup step. Alkaloids separation was performed on a C18, 250 mm x 4.6 mm, 5 μm column with the mobile phase containing ammonium carbonate and acetonitrile. The excitation and emission wavelengths were 330 and 420 nm respectively. The method was validated according to the Commission Decision 2002/657/EC and all parameters are in agreement with the requirements of the Decision. Linearity was determined for the concentration range of 25-400 μg/kg. The coefficient of determination (R2) for all curves was from 0.985 to 0.996. The limit of detection (LOD) was in the range 3.23 to 6.53 μg/kg and the limit of quantification (LOQ) from 11.78 to 13.06 μg/kg. The decision limit (CCα) ranged from 29.56 to 43.08 μg/kg and detection capability (CCβ) from 40.65 to 51.01 μg/kg. The highest coefficient of variation (CV) for repeatability was 14.3% and for reproducibility 15.4%.