title: Spectrophotometric determination of cobalt(II) and cyanocobalamin with vanillilfluorone and its applications.
abstract: Spectrophotometric determination of cobalt(II) was accomplished with vanillilfluorone (VF) in the presence of dimethylbenzyltetradecylammonium chloride (Zephiramine, Zep). In the determination of cobalt(II), Beer's law was obeyed in the range of 24-470 ng/ml, with an effective molar absorption coefficient (at 575 nm) and relative standard deviation of 1.35×10(5) l mol(-1) cm(-1) and 0.66% (n=5), respectively. The composition ratio of the colored complex was determined by the mole ratio and continuous variation methods, and it was found to be Co(II) : VF : Zep=1 : 2 : 4. Analysis of cyanocobalamin by the same procedure showed that cyanocobalamin could be determined in the concentration range of 0.5-0.11 µg/ml using the proposed method.
authors.affiliation: Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Hoshino
authors.forename: Momoka
authors.initials: M
authors.lastname: Matsushita
authors.forename: Megumi
authors.initials: M
authors.lastname: Samma
authors.forename: Mamiko
authors.initials: M
authors.lastname: Asano
authors.forename: Takako
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Fujita
mesh_terms: D001548:Benzalkonium Compounds / Q000737:chemistry; D016227:Benzoquinones / Q000138:chemical synthesis / Q000737:chemistry*; D003035:Cobalt / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D013053:Spectrophotometry / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D001548:Benzalkonium Compounds; D016227:Benzoquinones; D013501:Surface-Active Agents; C561124:vanillilfluorone; C005883:zephiramine; D003035:Cobalt; D014805:Vitamin B 12