Study On The Determination Of Sulfonamides Residues By High Performance Liquid Chromatography

Sulfonamides are a group of synthetic antibacterial drugs commonly used in veterinary practice for prophylactic and therapeutic purposes. The unreasonable or extensive use of sulfonamides in animal husbandry has been associated with large amounts of drug residues. In recent years, evidence had implicated sulfonamides as a possible thyroid carcinogenic agent, and they were also possibly associated with development of antibiotic resistance in humans as well as severe allergic reactions. It is necessary to monitor the residues of these drugs in animal derived food. A method was developed for simultaneous determination of sulfachlorpyridazine and sulfachlorpyrazine which are widely used in veterinary practice in chicken tissues (muscle, kidney and liver) using solid-phase extraction and high performance liquid chromatography.Chicken tissues were extracted with acetonitrile, followed by acetone, their extracts were defatted by hexane and then applied to positive ion exchanging MCX cartridge which was washed with 0.1mol/L hydrochloric acid followed by methanol. The retained drugs were eluted with 5% ammonium- acetonitrile. Elute was evaporated to dryness, the dry residue was dissolved by methanol and filtered. The two sulfonamides above were determined on C18 column with ultraviolet absorption detection at 270 nm, using acetonitrile-water which includes 0.017mol/L phosphoric acid (32/68, v/v) as eluent.Under these chromatography conditions, the above sulfonamides concentration had a good linear coefficient relation (r≥0.9997) in the range of 0.02～1.0μg/L. Recoveries at fortified level of 50, 100 and 200μg/kg in chicken muscle from tissues assay ranged from 72.10% to 84.06%, the within-day C.V ranged from 4.46% to 6.73% and between-day C.V ranged 5.27% to 8.91%. Recoveries in chicken kidney from tissues assay ranged from 71.18% to 84.78%, the within-day C.V ranged from 3.94% to 7.22% and between-day C.V ranged from 7.15% to 8.79%. Recoveries in chicken liver from tissues assay ranged from 70.58% to 80.42%, the within-day C.V ranged from 3.33% to 7.64% and between-day C.V ranged from 6.07% to 9. 4%. The detection limits were found to be 0.02mg/kg, the detection quantity were 0.04 mg/kg. This is a qualitative confirmatory method which will meet the demand of residue determination of SCP and SPZ in chicken tissues.