title: Agarose gel electrophoretic detection of six beta-lactam antibiotic residues in milk.
abstract: An electrophoretic method coupled with bioautography was developed for detection and identification of penicillin G, ampicillin, amoxicillin, cloxacillin, cephapirin, and ceftiofur residues in milk. The method uses a 2% agarose gel for electrophoresis, an overlay of PM indicator agar seeded with Bacillus stearothermophilus var. calidolactis, and incubation at 55 degrees C for 16-18 h. The new method separated and detected residues in milk at the levels of concern for the Food and Drug Administration (FDA) for penicillin G (5 ppb), cephapirin (20 ppb), and ceftiofur (50 ppb). The method also detected ampicillin, amoxicillin, and cloxacillin at 20, 30, and 30 ppb, respectively, but these levels are above those of concern for FDA (10 ppb).
authors.affiliation: U.S. Food and Drug Administration, Denver District Laboratory, CO 80225-0087, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Cutting
authors.forename: W M
authors.initials: WM
authors.lastname: Kiessling
authors.forename: F L
authors.initials: FL
authors.lastname: Bond
authors.forename: J E
authors.initials: JE
authors.lastname: McCarron
authors.forename: K S
authors.initials: KS
authors.lastname: Kreuzer
authors.forename: J A
authors.initials: JA
authors.lastname: Hurlbut
authors.forename: J N
authors.initials: JN
authors.lastname: Sofos
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D004587:Electrophoresis, Agar Gel / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000737:chemistry*; D012015:Reference Standards; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams