Determination of cefsulodin, cefmenoxime, and cefadroxil as residues on surfaces.

Cefsulodin, cefmenoxime, and cefadroxil are degraded instantaneously in aqueous sodium hypochlorite, sodium hypochlorite-detergent, or alkaline detergent solutions. These alkaline solutions are used to clean surfaces that have been exposed to the cephalosporins. The cleaned surfaces are monitored for residual drug levels (microgram) using a wet swab-dry swab technique. After extraction from the swabs, the content of the respective cephalosporin is determined in the solution by high-performance liquid chromatography. The limit of detection for each of the compounds is 0.1 microgram/ml. Recoveries from nonporous surfaces ranged from 56 to 102%.