ABSTRACT
A sensitive and reliable method using capillary HPLC with UV-diode array detection (DAD) has been developed and validated for the trace determination of residues of 10 beta-lactam antibiotics of human and veterinary use, in milk, chicken meat and environmental water samples. The analytes included ampicillin, amoxicillin, penicillin V, penicillin G, cloxacillin, oxacillin, dicloxacillin, nafcillin, piperacillin and clavulanic acid. Legal levels are regulated by the EU Council regulation 2377/90 in animal edible tissues for these compounds. For food analysis, a solid-phase extraction (SPE) procedure consisting in a tandem of Oasis HLB and Alumina N cartridges was applied for off-line preconcentration and cleanup. For water analysis, the first step was only necessary. The limits of detection for the studied compounds were between 0.04-0.06 microg l(-1) for water samples and 0.80-1.40 microg l(-1) (or microg kg(-1)) in the case of foods derived from animals. Average recoveries for fortified samples at different concentration levels ranged between 82.9% and 98.2%, with relative standard deviations (RSDs) lower than 9%. The method showed the advantages of capillary HPLC for the detection of these widely applied antibiotics in different samples at very low concentration levels.
Subject(s)
Anti-Bacterial Agents/analysis , Chromatography, High Pressure Liquid/methods , Environmental Pollutants/analysis , Food Analysis/methods , Fresh Water/chemistry , beta-Lactams/analysis , Animals , Anti-Bacterial Agents/chemistry , Chickens , Linear Models , Meat/analysis , Milk/chemistry , Reproducibility of Results , Sensitivity and Specificity , beta-Lactams/chemistryABSTRACT
A sensitive and reliable method using capillary zone electrophoresis with UV-diode array detection (CZE-DAD) has been developed and validated for trace determination of beta-lactam antibiotics in waste, well and river water matrices. Due to the lack of sensitivity of the UV-vis detection, a solvent extraction/solid-phase extraction (SPE) method applied for off-line preconcentration and cleanup of water samples, in combination with an on-line preconcentration methodology named large volume sample stacking (LVSS) have been applied. The analytes included nafcillin, dicloxacillin, cloxacillin, oxacillin, ampicillin, penicillin G and amoxicillin. Average recoveries for water samples fortified with the studied beta-lactams at different concentration levels (1.0, 2.0 and 4.0 microg/L) were ranging between 94 and 99%, with relative standard deviations (RSDs) lower than 10%. The precision, calculated as intra-day and inter-day standard deviations fell within acceptable ranges (3.3-7.2%). The limits of detection were estimated to range between 0.08 and 0.80 microgL(-1) for the studied compounds. All the samples analyzed were negative for all the analytes at these levels of concentration and the method showed its usefulness for the detection of these widely applied beta-lactam antibiotics in different kinds of waters.
