Application of a Novel Method for Measuring Carbadox Residues in Retail Pork

Carbadox (CBX) is approved for use in swine in the U.S. despite concerns due to its carcinogenicity, and pork containing carcinogenic residues may be entering the food supply. We developed and applied a new method to quantify the carcinogenic CBX residue desoxycarbadox (DCBX) and the noncarcinogenic residue quinoxaline-2-carboxylic acid (QCA) to a variety of retail pork products purchased in the Baltimore, MD, region. We analyzed 33 pork samples from 13 pork producers and did not detect DCBX or QCA in any sample. Information on CBX use was gathered from the integrators; seven (54%) did not respond, one confirmed CBX use, one reported no CBX use, and we could not determine CBX use based on responses from four integrators. While CBX remains in use in the U.S., the application of an analytical method that can detect CBX residues of carcinogenic concern in target edible tissues is necessary to protect consumers.