title: Role of anthranilic acid in background levels of sulfonamide in porcine livers when determined by the Tishler method.
abstract: Anthranilic acid occurs in excised swine livers as a result of temperature abuse before and/or after freezing. The tryptophan metabolite is the major source of the variable non-sulfonamide background level frequently encountered in the Tishler method for determining sulfonamide residues in swine livers. Diazotized anthranilic acid reacts slowly with N-1-(naphthyl)ethylenediamine [k(s-1) = 5.79 (+/- 0.07) X 10(-5)] and the final background level depends on the time elapsed between addition of the coupling agent and spectrophotometric determination. Kynurenine was tentatively identified as a minor source of the non-sulfonamide background level.
mesh_terms: D000818:Animals; D008099:Liver / Q000032:analysis*; D013048:Specimen Handling; D013449:Sulfonamides / Q000032:analysis*; D013552:Swine; D013696:Temperature; D062367:ortho-Aminobenzoates / Q000032:analysis*
chemical_list: D013449:Sulfonamides; D062367:ortho-Aminobenzoates; C031385:anthranilic acid