title: Chemiluminescence investigation of carbon dioxide-enhanced oxidation of dihydralazine sulfate by peroxynitrite and its application to pharmaceutical analysis.
abstract: A weak chemiluminescence (CL) emission was observed upon mixing peroxynitrite (ONOO(-)) with dihydralazine sulfate (DHZS). Further experiments showed that carbonate media could enhance the CL emission significantly. Based on these observations, a novel flow injection CL method for the determination of DHZS is developed. The CL signal is linearly with DHZS concentration in the range of 0.01-3.0 microg mL(-1) with a detection limit of 3.6 ng mL(-1). The method was applied to the analysis of DHZS in pharmaceutical preparations and compared well with the high-performance liquid chromatography (HPLC) method. The CL mechanism is discussed and it is postulated that it involves nitrosoperoxocarboxylate (ONOOCO(2)(-)), which is an unstable adduct and can rapidly decompose into *NO(2) and *CO(3)(-) radical. The latter can then oxidize DHZS to give out strong CL emission.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Analytical Science, Department of Chemistry, Northwest University, Taibai Road #229, Xi'an 710069, China. xfyang@mail.china.com
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Yang
mesh_terms: D002138:Calibration; D002245:Carbon Dioxide / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D004078:Dihydralazine / Q000032:analysis* / Q000737:chemistry*; D017022:Flow Injection Analysis / Q000379:methods; D005609:Free Radicals / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D049449:Luminescence; D015394:Molecular Structure; D009573:Nitrites / Q000737:chemistry; D009608:Nitrous Acid / Q000737:chemistry; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D002254:Carbonates; D005609:Free Radicals; D009573:Nitrites; D002245:Carbon Dioxide; D030421:Peroxynitrous Acid; C005686:sodium carbonate; D006861:Hydrogen Peroxide; D004078:Dihydralazine; D009608:Nitrous Acid