title: Simultaneous determination of vanadium(IV) and vanadium(V) by flow injection analysis using kinetic spectrophotometry with Xylenol Orange.
abstract: A flow injection method of analysis has been developed for the simultaneous determination of V(IV) and V(V) using the difference in the rate of complex formation between vanadium in two different oxidation states and Xylenol Orange in acidic media. The proposed method used a spectrophotometric detector equipped with two flow cells aligned with the same optical path to yield two successive peaks per each sample injection. V(IV) and V(V) were determined by solving simultaneous equations in two unknowns, the concentrations of V(IV) and V(V), obtained from measurements of the two peak heights. The detection limit calculated as 3σ of noise signals was 0.01μg/mL for both V(IV) and V(V). The relative standard deviations for V(IV) and V(V) at the 1μg/mL level were 1.6 and 2.4%, respectively. The sample throughput was found to be about 19h(-1). The proposed method was successfully applied to the simultaneous determination of V(IV) and V(V) in synthetic scrubbing solutions used in desulphurization with reasonable accuracy.
authors: Department of Applied Chemistry and Biochemistry, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. koguma@faculty.chiba-u.jp
authors: Koichi
authors: K
authors: Oguma
authors: Osamu
authors: O
authors: Yoshioka
authors: Junji
authors: J
authors: Noro
authors: Hiroki
authors: H
authors: Sakurai
mesh_terms: D002021:Buffers; D017022:Flow Injection Analysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013454:Sulfoxides / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry; D013997:Time Factors; D014639:Vanadium / Q000032:analysis* / Q000737:chemistry*
chemical_list: D002021:Buffers; D010636:Phenols; D013454:Sulfoxides; D014639:Vanadium; D013455:Sulfur; C016833:xylenol orange