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

Abstract

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.