Agilent 1100 Series LC-ESI-MS Nitrofuran Metabolite Analysis Application Note

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of the metabolites of four nitrofuran antibacterial drugs in chicken tissues: furazoli- done, furaltadone, nitrofurazone, and nitrofurantoin. Sample clean-up and analyte enrichment were performed by liquid-liquid extraction with ethyl acetate followed by solvent washing, hydrolysis of the protein-bound drug metabolites, and derivatization with 2-nitrobenzaldehyde (2-NBA). ESI parameters were optimized, and the chro- matographic separation of all metabolites was examined. Each metabolite produced a simple mass spectrum con- taining a strong signal corresponding to [M+H]+. Metabolite calibration curves, in the 0.25 to 1 ng/mL range, exhibited correlation coefficients greater than 0.999. The limit of detection (LOD) for each analyte ranged from 0.02 to 0.06 ng/mL. Introduction The four drugs shown in Figure 1, furazolidone, furaltadone, nitrofurazone, and nitrofurantoin, belong to the group of nitrofuran antibacterial drugs. These drugs have been widely used as feed additives to prevent bacterial enteritis by Escherichia coli and Salmonella in cattle, fish, swine. The main metabolites of these drugs are 5-methyl-5-nitro-2-furaldehyde and 5-amino-5-nitro-2-furaldehyde, which are produced by the hydrolysis of the protein-bound drug metabolites.

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