Automatic determination of iodine species in natural waters by a new flow-through electrode system

Journal Article · Wed May 01 04:00:00 EDT 1985 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00283a045· OSTI ID:5383924

Nakayama, E; Kimoto, T; Okazaki, S

Inorganic iodine species, iodide, and iodate in seawater have been determined by a variety of classical methods of analysis. Only the spectrophotometric procedure using the absorbance of I/sub 3//sup -/ at 353 nm is utilized for an automatic determination. This method, however, has a few disadvantages such as interference with nitrite and insufficient accuracy for low concentration of iodide. This paper describes a new electrochemical technique for the automatic determination of iodine species in natural waters. The iodide is electrochemically oxidized to iodine and quantitatively concentrated on a carbon wool electrode in a preconcentration cell. After the interference ions were removed, the iodine was eluted with reducing agent followed by the determination at the polished Ag/sub 3/SI electrode in the detection cell. The iodate is determined after being reduced to iodide by reducing agent. The resulting amperometric current is proportional to iodide or iodate concentration in the original solution. The sensitivity is 0.4-0.5 ..mu..A/..mu..g I/sup -/ and the detection limit is 5 ng of I/sup -/. Iodine species can be accurately determined as iodide and total iodine (iodide + iodate) from less than 50 mL of seawater sample by this method. 5 references, 7 figures, 1 table.

• Research Organization: Kyoto Univ., Japan
• OSTI ID: 5383924
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 57:6; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INFORMATION
IODIDES
IODINE
IODINE COMPOUNDS
NONMETALS
NUMERICAL DATA
OXIDATION
OXYGEN COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
SEAWATER
VOLTAMETRY
WATER