Electrophoretic analysis of quinone anion radicals in acetonitrile solutions using an on-line radical generator.
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.
Esaka
Yukihiro
Y
Gifu Pharmaceutical University, Gifu, Japan. esaka@gifu-pu.ac.jp
Okumura
Noriko
N
Uno
Bunji
B
Goto
Masashi
M
D000838:Anions; D019075:Electrophoresis, Capillary / Q000379:methods*; D005609:Free Radicals; D006860:Hydrogen Bonding; D011809:Quinones / Q000737:chemistry / Q000302:isolation & purification*
D000838:Anions; D005609:Free Radicals; D011809:Quinones