Maduramicin Acid

A simple green hydrothermal method was proposed for synthesis of highly fluorescent nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) using citric acid and thiosemicarbazide. The produced N,S-CQDs were subjected to extensive spectroscopic characterization and applied as fluorescent nanosensors for the sensitive spectrofluorimetric determination of salinomycin and maduramicin directly without prior derivatization for the first time. The obtained N,S-CQDs showed strong emission band at 430 nm after excitation at 360 nm. The native fluorescence of N,S-CQDs was found to be quenched by the addition of increased concentrations of each drug. Method validation revealed a wide linear relationship between the fluorescence quenching of N,S-CQDs and the concentration of each drug in the range of 10.0-300.0 μM with detection limits of 2.07 μM and 1.34 μM for salinomycin and maduramicin, respectively. The developed method has been efficiently applied for estimation of analytes in six raw matrices with high recoveries.

The control of levels of anticoccidial feed additives in targeted feeds plays an important role in the assurance of efficiency of animal treatment, prevention of drug resistance, and food safety. The robust and labour-efficient method for the simultaneous determination of six ionophore coccidiostats (lasalocid, maduramicin, monensin, narasin, salinomycin, and semduramicin) in targeted feed has been developed. Properly grinded and homogenized feed sample was spiked with internal standard (monesin methyl ester) and extracted with methanol. The extract was analysed with reversed phase HPLC without any further purification. The separation of the analytes with conventional C18 and core-shell columns was compared. Lasalocid was analysed with fluorescence detection, whereas other ionophores were detected with UV-Vis detector after derivatisation with vanillin in the presence of sulfuric acid. Fortified samples and targeted feeds at authorized levels were used for method validation. Recovery was in the range of 85-110%, depending on the analyte. The within-laboratory reproducibility did not exceed the target value from Horwitz equation. The results of the proficiency tests (z-scores in the range of -1.0 to 1.9) confirmed the reliability of the developed protocol.

A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method and an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining eight coccidiostat (halofuginone, lasalocid, maduramicin, monensin, narasin, nigericin, robenidine and salinomycin) residues in beef were developed and compared. Samples were extracted with a mixture of acetic acid, acetonitrile and ethyl acetate and were then purified on a C18solid-phase extraction (SPE) column. The purified samples were analyzed by HPLC-MS/MS and UPLC-MS/MS, using 0.1% formic acid-water solution (A) and pure methanol (B) as the mobile phase. The samples were fractionated on a C18column using different gradient elution procedures, followed by qualitative analysis using a mass spectrometer operated in multiple reaction monitoring (MRM) mode with positive electrospray ionization; the external standard method was used for quantitation. At spiked levels that ranged from the limit of quantification (LOQ) to 100 μg/kg, the average recoveries were 71.96%-100.32% and 71.24%-89.24%, with relative standard deviations (RSDs) of 2.65%-12.38% and 2.98%-14.86% for UPLC-MS/MS and HPLC-MS/MS, respectively. The limits of detection (LODs) and LOQs of the eight coccidiostats were 0.14-0.32 μg/kg and 0.43-1.21 μg/kg, respectively, for UPLC-MS/MS analysis and 0.16-0.58 μg/kg and 0.53-1.92 μg/kg, respectively, for HPLC-MS/MS analysis. Both methods had good accuracy and precision, but UPLC-MS/MS had higher sensitivity than HPLC-MS/MS.