title: Detection of antithyroid residues in meat and some organs of slaughtered animals.
abstract: A simple method is described for the routine detection of antithyroid residues in thyroid, liver, kidney and meat contaminated at levels as low as 10 ppb (10 parts per 10(9)). Tissue samples (2 g) are homogenized in methanol, contaminating lipids and amino acids are removed and the antithyroid residues are subjected to reaction with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in buffer. The NBD derivatives are extracted with diethyl ether and separated by thin-layer chromatography. After spraying with cysteine or mercaptoethylamine, the antithyroid residues appear as fluorescent spots. The detection limit of these compounds is of the order of 200 pg.
mesh_terms: D000818:Animals; D013956:Antithyroid Agents / Q000032:analysis* / Q000378:metabolism; D001393:Azoles / Q000378:metabolism; D002417:Cattle; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D005453:Fluorescence; D005504:Food Analysis; D005525:Food-Processing Industry; D007668:Kidney / Q000032:analysis*; D008099:Liver / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D013961:Thyroid Gland / Q000032:analysis*
chemical_list: D013956:Antithyroid Agents; D001393:Azoles