Application of Solid Phase Extraction for the Analysis of Sulfonamides in Milk by High Performance Liquid Chromatography

A High Performance Liquid Chromatographic (HPLC) method for the analysis of Sulfadiazine, Sulfathiazole, Sulfapyridine, Sulfamerazine, Sulfamethiazole, Sulfamethazine, Sulfachloropyridazine, Sulfadimethoxine, and Sulfaquinoxaline is described. Milk (5 ml) is diluted with 5 ml potassium phosphate buffer (1 M, pH 4.4) and passed through a Cyclobond-I solid phase extraction (SPE) column. Sulfonamides, retained on the SPE column, are eluted with 4 ml methanol. The eluate is further cleaned using an alumina and AGMP-1 ion exchange column to remove coeluting matrix components. The cleaned extract containing sulfonamides is analyzed by HPLC using a reverse phase column and diode array detector at 265 nm.