A procedure was investigated for the gas chromatographic determination of sulfadiazine (SD), sulfamerazine (SM), sulfisomidine (SIM), sulfadimetoxine (SDM) and sulfisoxazole (SIX) in chicken tissues and egg.
Sulfonamides were extracted with a mixture of chloroform-acetic acid (99:1) and partitioned into sodium hydroxide solution. After suitable pH (7.0-8.0) adjustment and saturation of sodium chloride, the sulfonamides were extracted with ethyl acetate. Then the solvent was removed, the residue was methylated with diazomethane followed by acylation with heptafluorobutyric anhydride in 1, 4-dioxane at 110°C for 30min. The resulting derivatives were measured by ECD gas chromatography and separated from each other on a 2m glass column packed with Chromosorb W coated with 1.5% SE 30.
Control chicken muscle, liver, kidney and egg showed no significant interference. In chicken muscle, the limits of detection were 0.05ppm for SD, SM, SIM, SIX and 0.1ppm for SDM.