furaltadon and 3-amino-2-oxazolidinone

Regulatory monitoring for nitrofuran drug residues in aquaculture products has largely focused on LC-MS/MS. In addition, there is a need for facile and high-throughput screening methods for monitoring programs. We evaluated the performance of Ridascreen (R-Biopharm) ELISA kits for nitrofuran drug residues in fish muscle, with verification by LC-MS/MS. Kits were available for 3-amino-2-oxazolidinone (AOZ) and 3-amino-5-morpholino-methyl-2-oxazolidinone (AMOZ) side-chains of furazolidone and furaltadone, respectively. We found good repeatability in fortified and incurred muscle samples, with RSDs ranging from 1.8% to 7.6%. Recoveries of AOZ and AMOZ from muscle fortified at levels of 0.5-2 ng/g ranged from 98% to 114%. Excellent selectivity was demonstrated. The minimum detection limits (MDLs) for AOZ and AMOZ in muscle were 0.05 and 0.2 ng/g, respectively. ELISA data were highly correlated with those of LC-MS/MS. Results of this study support the use of these kits as screening assays for nitrofuran residues in fish muscle.

Topics: Animals; Aquaculture; Calibration; Chromatography, Liquid; Drug Residues; Enzyme-Linked Immunosorbent Assay; Food Analysis; Furazolidone; High-Throughput Screening Assays; Ictaluridae; Morpholines; Nitrofurans; Oxazolidinones; Seafood; Tandem Mass Spectrometry

Depletion of the nitrofuran antibiotics furazolidone, furaltadone, nitrofurantoin and nitrofurazone and their tissue-bound metabolites AOZ, AMOZ, AHD and SEM from pig muscle, liver and kidney tissues is described. Groups of pigs were given feed medicated with one of the nitrofuran drugs at a therapeutic concentration (400?mg?kg(-1)) for ten days. Animals were slaughtered at intervals and tissue samples collected for analysis for six weeks following withdrawal of medicated feed. These samples were analysed both for parent nitrofurans (using LC-MS/MS and HPLC-UV), and for tissue-bound metabolites (using LC-MS/MS). The parent drugs were detectable only sporadically and only in pigs subjected to no withdrawal period whatsoever. This confirms the instability of the four major nitrofuran antibiotics in edible tissues. In contrast, the metabolites accumulated to high concentrations in tissues (ppm levels) and had depletion half lives of between 5.5 and 15.5 days. The metabolites of all four drugs were still readily detectable in tissues six weeks after cessation of treatment. This emphasizes the benefits of monitoring for the stable metabolites of the nitrofurans.

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents, Urinary; Chromatography, High Pressure Liquid; Chromatography, Liquid; Drug Residues; Food Contamination; Furazolidone; Hydantoins; Kidney; Liver; Mass Spectrometry; Morpholines; Muscle, Skeletal; Nitrofurans; Nitrofurantoin; Nitrofurazone; Oxazolidinones; Semicarbazides; Swine