Multi-Residues Determination Method Of Five Sulfonamides In Albumen And Egg Yolk And Its Residue Depletion In Eggs Of Laying Hens

This paper includes two parts of research: Multi-residues Determination Method ofFive Sulfonamides in Albumen and Egg Yolk by HPLC; Residues depletion ofsulphamonomethoxine in eggs of laying hens. The results were shown as follows:1. Multi-residues Determination Method of Five Sulfonamides in Albumen and EggYolk by HPLCA high performance liquid chromatography method was developed for determinationof Sulfadiazine, Sulfamethazine, Sulfamethoxypyridazine, Sulfamethoxazole andSulfamonomethoxine in albumen and yolk. Samples were extracted with acetonitrile,thesupernatant was evaporated to dryness and residues were dissolved in the mobilephase.Albumen extracts were directly analyzed by HPLC, while hexane was added to theyolk extracts to remove lipin, then the yolk extract was analyzed by HPLC. The HPLCsystem included a reversed phase column (ZORBAX SB-C18 5μm,250mm~*4.6mm(i.d)),a mobile phase of methanol and 1% acetic acid buffer, and a UV detector set at 270nm.therecovery of five sulfonamides in albumen at 0.5mg/kg,0.1mg/kg and 0.05mg/kg levels was84.3%～100.4%,and in egg yolk was 80%～91.8%.the CV is 1.1%～7.0% in eggwhite,and 1.1%～11.5% in egg yolk respectively. The detection limit is 0.01 mg/kg in eggwhite, and 0.03mg/kg in egg yolk.2. Residue depletion of sulphamonomethoxine in eggs of laying hensThe study is conducted to determine residue depletion of sulphamonomethoxine ineggs.30 hens were divided into three groups,containing groupⅠ,Ⅱand controlgroup.Laying hens were administrated sulphamonomethoxine through drinking water for7 successive days at three levels(1g/L for groupⅠ,2g/L for groupⅡ,0g/L for controlgroup).eggs laid during the treatment and the 36 days after the withdrawal were collected,the sulphamonomethoxine residues in albumen and yolk were analyzed byhigh performance liquid chromatography with detector UV(HPLC-UV), The detectionlimits of the method in albumen and yolk are both 0.0.1mg/kg. Sulphamonomethoxine wasfound to appear already in yolk and albumen on the first day of treatment.the residuesincreased with the medication days;the concentration in albumen reached a constant levelon the fifth day of dosing, whereas on the sixth day of dosing in yolk;the ratio of thepeak drug levels between albumen and yolk is about6.0 (7.06 for groupⅠ, 5,75 for groupⅡ); Maximum concentrations in albumen were much higher than those in yolk, much ofthe sulphamonomethoxine residue was detected in albumen; After withdrawal ofmedication,the residues in albumen declined below the detection limit at 28 days Afterwithdrawal for groupⅡ,and those in yolk are at 30 days and 26 days for groupⅠ,Ⅱrespectively, the sulphamonomethoxine residue in albumen of groupⅠwas stilldetected at 36 days after withdrawal.