title: Electrophoretic analysis of quinone anion radicals in acetonitrile solutions using an on-line radical generator.
abstract: We have investigated analysis of anion radicals of phenanthrenequinone (PhQ) and anthraquinone (AQ) using acetonitrile-capillary electrophoresis (CE) under anaerobic conditions. PhQ and AQ have relatively high negative reduction potentials meaning that their anion radicals are re-oxidized quite readily by the surrounding O(2) to disappear during analysis and we failed to detect them with our previous system. In this work, we have developed an on-line system combining a unique electrolysis cell for generation of the radicals and a CE unit to keep the analysis system free from external O(2) molecules and to reduce analysis time remarkably. As a result, electrophoretic detection of the anion radicals of PhQ and AQ has been achieved. Furthermore, we have observed hydrogen-bonding interaction between the anion radicals and dimethylurea (DMU) using the present system and have indicated a characteristic interaction of the anion radical of PhQ as an ortho-quinone with DMU.
authors.affiliation: Gifu Pharmaceutical University, Gifu, Japan. esaka@gifu-pu.ac.jp
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Esaka
authors.forename: Noriko
authors.initials: N
authors.lastname: Okumura
authors.forename: Bunji
authors.initials: B
authors.lastname: Uno
authors.forename: Masashi
authors.initials: M
authors.lastname: Goto
mesh_terms: D000838:Anions; D019075:Electrophoresis, Capillary / Q000379:methods*; D005609:Free Radicals; D006860:Hydrogen Bonding; D011809:Quinones / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000838:Anions; D005609:Free Radicals; D011809:Quinones