Sulfa drugs have antimicrobial activity and are used as veterinary drugs for the prevention and treatment of infectious diseases in livestock and fishery products. The Law for Ensuring the Safety of Feed and Improving the Quality of Feedstuffs stipulates standards for use, but the transfer of synthetic antibacterial agents to livestock and fishery products and their persistence have become recognized. The Food Sanitation Law was amended, and a positive list system was introduced May 29, 2006 to set limits for sulfa residues in foods.
The flow diagram below describes the pretreatment of livestock and fishery products prior to analysis by LC/MS (/MS).