Development of an enzyme-linked immunosorbent assay for the determination of maduramicin in broiler chicken tissues

Validated spectrophotometric determination of maduramicin ammonium using three charge transfer complexation reactions

Direct spectrophotometric determination of Maduramicin ammonium (MAD) represents an analytical challenge since it is a weak UV-absorbing and lacking a strong chromophore. This work represents the first spectrophotometric determination of MAD as no direct spectrophotometric or colorimetric determination methods for MAD are available in the literature. The present study illustrates the development of three simple, rapid and inexpensive colorimetric methods for the routine quality control analysis of MAD based on the formation of colored charge transfer complexes with three electron acceptors namely p-chloranilic acid (p-CA), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and picric acid (PA). The color products of MAD with p-CA, DDQ and PA were measured at 519, 588 and 405nm respectively. The proposed methods were validated in terms of linearity, ranges, precision, accuracy, robustness and limits of detection and quantification. MAD was effectively determined over concentration ranges of 100-1000, 25-250 and 30-150μg/mL using p-CA, DDQ and PA, respectively with good linearity as shown by the values of correlation coefficients not less than 0.9991. The developed methods were successfully implemented in the assay of MAD powder pharmaceutical formulation for veterinary use.

Liquid chromatography tandem mass spectrometry determination of maduramycin residues in the tissues of broiler chickens

Maduramycin is a polyether ionophoric coccidiostat used to prevent coccidiosis in poultry at a prescribed concentration over a certain time interval. Due to public health concerns about the presence of coccidiostat residues in poultry, the aim of the present study was to determine the level of maduramycin residues in the tissues of broiler chickens fed commercially produced feed containing 5 mg kg(-1) of maduramycin in complete feed throughout the 5-day withdrawal period (WP). The residues were investigated by liquid chromatography (LC) coupled with electrospray ionisation (ESI) tandem mass spectrometry (MS/MS). The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.3 and 0.8 microg kg(-1), respectively. The average recovery based on matrix-fortified calibrations for chicken tissues was 90%. Maduramycin was found to be rapidly distributed in all tissues. The highest concentrations of maduramycin residues were found in the heart followed by the skin, liver, gizzard, kidneys and, finally, muscle (thigh and breast). On day 5 of the WP, residue concentrations of maduramycin did not decline below the LOQ of the method. Our results emphasize the need to establish a maximum residue limit (MRL) for maduramycin to control its residue levels in edible tissues from chickens before slaughter.