Sulphonamide and dapsone residues in bovine milk following intramammary infusion

The elimination into bovine milk of sulphonamides (sulphadimidine and sulphamethoxypyridazine) and dapsone following intramammary infusion was studied. Determination of sulphonamides and dapsone in milk was performed by a high performance liquid chromatographic method with UV detection. The limit of quantification was 0.01 microgram/ml. Withdrawal times were established considering the maximum residue limits fixed by the European Community (100 micrograms/kg for sulphonamides and 25 micrograms/kg for dapsone). The diffusion of residues into milk from a quarter infused by the intramammary route to the untreated quarters was also studied.