Sensitivity enchancement by potentiometric flow-injection analysis based on redox reaction with an iron(III)-iron(II) buffer

✍ Scribed by Nobuhiko Ishibashi; Toshihiko Imato; Sumio Yamasaki; Hiroki Ohura

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 528 KB
• Volume: 261
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(92)80220-2

✦ Synopsis

Ahstlael

Highly sensltlve potentlometrtc flow-mnjectlon analysis for oxldatnre species such as bromate, chlorite, dlchmmate, hydrogen peromde and ozone IS described, using an Fe(III)-Fe(U) potential buffer containing bronude The method IS based on detectIon of large transient potential changes of an oxldatlon-reduction potential electrode which appear 1x1 short period after mwng a sample with the potential buffer This large transient potential change 1s due to bromme generated by the reaction of the sample with bromide m the potential buffer Analytical sensltlvltles obtamed by the transient change of potential are enhanced 25350-fold compared Hrlth that usmg the change m eqmhbnum potential Detection limits of 5 X 10-s M for bromate, 1 X lo-' M for chlorite and 3 X lo-' M for &chromate were obtained by using a 0 01 M Fe (III)-0 01 M Fe (II) potential buffer containing 0 4 M NaBr and 1 2 M H,SO, For the determmation of hydrogen peromde, the addition of ammomum molybdate to the potential buffer accelerates the generation of bromme caused by the reactIon of hydrogen peroxide with bronude and thus enhances the sensltivlty