Simultaneous determination of four sulfonamide residue in the manure of livestock and poultry by HPLC with fluorescence detection

A method for the simultaneous determination of four sulfonamides(sulfamerazine(SM1),sulfachlorpyridazine(SCP),sulfadimoxine(SDM′),sulfaquinoxaline(SQ)) residues in manure of livestock and poultry was developed by using high performance liquid chromatography(HPLC) with fluorescence detection detector.The samples were extracted with 25 mL methanol for three times,and then the combined extracts were evaporated to dryness under reduced pressure at 45 ℃.The residue was dissolved in 0.1 mol · L-1 HCl and the analytes were derived with fluorescamine.The chromatographic separation was performed on a C18 column with a gradient elution program using a mixture of acetonitrile:0.5% acetic acid=40 ∶60 as mobile phase.The four sulfonamides were separated within 20 min.The calibration curve was linear in the range of 0.05—5.00 mg · L-1 and R20.999.The limit of quantification(LOQ) was 2.3,6.3,4.3 and 9.6 μg · kg-1 for SM1,SCP,SDM′ and SQ in manure of livestock and poultry.The recovery efficiencies were 74.91%— 81.82%,78.45%—91.43% and 86.10%—92.88%,with RSD 8.82%(n=5)at the spiking level of 50、100、1000 μg · kg-1,respectively.The method was suitable for the detection of SA residues in manure of livestock and poultry.