Restricted-access media liquid chromatography for determination of sulfamonomethoxine, sulfadimethoxine, and their N4-acetyl metabolites in eggs

Simultaneous determination of sulfamonomethoxine, sulfadimethoxine, and their N4-acetyl metabolites in eggs using restricted-access media high performance liquid chromatography (RAM-HPLC) with a photo-diode array detector is developed. The target compounds are extracted by a handheld ultrasonic homogenizer with saturated ammonium sulfate solution followed by centrifugation. The separation is performed by a Hisep shielded hydrophobic phase column, isocratic elution with 0.3% acetic acid solution (pH 2.9, in water)–ethanol (75:25, v/v). Average recoveries from samples spiked at 0.1–1.0 ppm for each drug were >91% with relative standard deviations within 4%. The limits of quantitation were ≦0.08 ppm. No hazardous-chemicals were used in all the processes.