title: Determination of ampicillin residues in milk by ion-pair reversed phase high performance liquid chromatography after precolumn derivatization.
abstract: A high performance liquid chromatography method has been developed for the determination of ampicillin residues in milk. The method involves extraction of ampicillin from milk with trichloroacetic acid solution followed by concentration on a conditioned C18 solid phase extraction column, acetylation with acetic anhydride in aqueous solution (pH 8.0) at ambient temperature for 3 min followed by reaction with 2 M 1, 2, 4-triazole and 10(-2) M mercury (II) chloride solution (pH 9.0) at 65 degrees C for 10 min. The resulting product is eluted on a C18 column with a mobile phase containing phosphate buffer (pH 6.5; 0.1 M), the ion-pairing agent tetrabutylammonium hydrogenosulphate, acetonitrile and methanol. The detection limit of the method is 3 ng ml-1 in milk.
authors.affiliation: Ministère de l'Agriculture et de la Pêche, Unité d'Innovation Technique en Contaminants Médicamenteux et Désinfectants, Javené, Fougères, France.
authors.forename: E
authors.initials: E
authors.lastname: Verdon
authors.forename: P
authors.initials: P
authors.lastname: Couedor
mesh_terms: D000089:Acetic Anhydrides; D000667:Ampicillin / Q000031:analogs & derivatives / Q000032:analysis*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004350:Drug Residues / Q000032:analysis; D007202:Indicators and Reagents; D008892:Milk / Q000737:chemistry*; D014230:Triazoles
chemical_list: D000089:Acetic Anhydrides; D007202:Indicators and Reagents; D014230:Triazoles; C045575:1,2,4-triazole; C031800:acetic anhydride; D000667:Ampicillin