Quinolones Pipemidic Acid Research Articles

Analytical approach for the simultaneous determination of quinolones in edible animal products. Modeling pH–modulated fluorescence excitation–emission matrices four–way arrays

This paper describes a novel procedure for the simultaneous determination of four quinolones pipemidic acid, enoxacin, marbofloxacin and enrofloxacin in different edible animal tissues. It is based on third–order data excitation–emission fluorescence matrices modulated by pH gradient, generated in situ through the hydrolysis of glucono delta–lactone. To overcome the strongly overlapped spectra within the analytes, and also with the highly complex tissue matrix, we have used the multivariate calibration procedure unfolded partial least–squares coupled to residual trilinearization (U–PLS/RTL). The method has been validated by application to bovine kidney, chicken and porcine meat samples, fortified at concentration levels between 70 and 600 µg kg−1 corresponding to values near the maximum residue level (MRL) regulated by the European Community. Good recoveries were obtained for all analytes, with values between 80% and 113%, depending on the quinolone and the matrix.

Trace determination of fluoroquinolone antibacterial agents in urban wastewater by solid-phase extraction and liquid chromatography with fluorescence detection.

Fluoroquinolones (FQs) are among the most important antibacterial agents (synthetic antibiotics) used in human and veterinary medicine. An analytical method based on reversed-phase liquid chromatography with fluorescence detection was developed and validated for the simultaneous determination of nine FQs and the quinolone pipemidic acid in urban wastewater. Aqueous samples were extracted using mixed-phase cation-exchange disk cartridges that were subsequently eluted by ammonia solution in methanol. Recoveries were above 80% at an overall precision of better than 10%. Instrumental quantification limits varied between 150 and 450 pg injected. The presented method was successfully applied to quantify FQs in effluents of urban wastewater treatment plants. The two most abundant human-use FQs, ciprofloxacin and norfloxacin, occurred in primary and tertiary waste-water effluents at concentrations between 249 and 405 ng/L and from 45 to 120 ng/L, respectively. The identity of FQs in urban wastewater was confirmed by recording full fluorescence spectra and liquid chromatography directly coupled to tandem mass spectrometry. These results indicate that conventional environmental risk assessment overestimates FQ concentrations in surface waters by 1 to 2 orders of magnitude.