title: Carbon fiber cylindrical microelectrode-based detector for the determination of antithyroid drugs.
abstract: An amperometric flow-injection method for the determination of antithyroid drugs such as 6-methyl-2-thiouracil (MTU) using a carbon fiber cylindrical microelectrode-based detector is reported. A home-made flow-cell specially adapted for working with cylindrical microelectrodes ranging between 4 and 10 mm in length was used for this purpose. Methanol containing 0.05 mol l(-1) tetrabutylammonium perchlorate as the supporting electrolyte was employed, and a potential of +1.6 V was selected for the amperometric detection of MTU. No cleaning or electrode surface regeneration of the fiber was necessary during the whole working day. A limit of detection of 2.6x10(-7) mol l(-1) (37 mug MTU l(-1)) was achieved. The method was applied to the determination of MTU in spiked feed samples (peas and corn flour), at the 142 mug g(-1) level. The procedure involved the extraction of the drug in methanol, a clean-up step using Florisil cartridges and the use of the standard additions method. Recoveries of 81+/-6 and 85+/-8% were obtained for peas and corn flour, respectively.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Guzmán
authors.forename: Lourdes
authors.initials: L
authors.lastname: Agüí
authors.forename: María
authors.initials: M
authors.lastname: Pedrero
authors.forename: Paloma
authors.initials: P
authors.lastname: Yáñez-Sedeño
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón