University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Chlorite

  • IUPAC Name: chlorite
  • Molecular Formula: ClO2-
  • CAS Registry Number: 14998-27-7
  • InChI: InChI=1S/ClHO2/c2-1-3/h(H,2,3)/p-1
  • InChI Key: QBWCMBCROVPCKQ-UHFFFAOYSA-M

@ ChemSpider@ NIST@ PubChem

Citations 6

"Selectivity Enhancement By Flow Injection Analysis"
Anal. Chim. Acta 1986 Volume 179, Issue 1 Pages 259-267
G. E. Spacey, D. A. Hollowell, K. G. Miller, M. R. Straka and G. Gordon

Abstract: Flow injection analysis was used to improve the selectivity of several existing methods. By kinetic discrimination, O3 is determined by the decolorization of indigo blue at 600 nm with a coefficient of variation of <1%, and ClO2 is determined by chemiluminescence with luminol, each in the presence of Cl. Chlorate can be determined by its reaction with I- in 12 M HCl, the absorbance being measured at 370 nm. The detection limit is 1 µM and the coefficient of variation are <5%. Chlorite and ClO3- are determined by injecting 12 M HCl in front of the sample and a carrier solution of pH 4.0 after it, thus forming two peaks, the first of which corresponds to total ClO3- and ClO2- and the second to ClO2- only. A dual-phase gas diffusion system for hydride generation provides a significant decrease in interference by transition metals.
Chemiluminescence Spectrophotometry Spectrophotometry Sample preparation Extraction Gas diffusion Interferences Kinetic Selectivity Tecator

"Utilization Of Kinetic-based Flow Injection Methods For The Determination Of Chlorine And Oxychlorine Species"
Anal. Chim. Acta 1989 Volume 224, Issue 2 Pages 383-391
G. Gordon, K. Yoshino, D. G. Themelis, D. Wood and G. E. Pacey

Abstract: The flow injection system was a Tecator 5020 analyzer. with a Tecator Chemifold II, and the detector was a Tecator 5024 FIAstar photometer with a 5024-011 optical unit and a 5032 controller. Samples were injected into water as carrier stream and mixed in a coil with 0.02 M or 12 M HCl, then this solution was mixed with 0.3 M KI reagent. The absorbance of the resulting I3- was measured at 370 nm in a 1-cm flow cell (volume 18 µL). With use of 0.02 M HCl, the signal is due to ClO2-, and with use of 12 M HCl it corresponds to ClO2- plus ClO3-, for solution free from ClO2 and/or Cl. By analysis at pH 8.3, ClO2 and free Cl can be determined without interference from the anions; oxalic acid can be used to mask Cl in the determination of ClO2 at pH 8.3. Conditions are given for determining each species without interference; calibration ranges were 0.2 to 10, 0.3 to 10, 0.08 to 5 and 0.08 to 5 mg L-1 for Cl, ClO2, ClO2- and ClO3-, respectively. The method is intended for application to drinking water.
Water Spectrophotometry Tecator Interferences Buffer Kinetic

"Determination Of Low Concentrations Of Chlorite And Chlorate Ions By Using A Flow Injection System"
Anal. Chim. Acta 1989 Volume 225, Issue 2 Pages 437-441
Demetrius G. Themelis, Delmer W. Wood and Gilbert Gordon

Abstract: Determination of ClO2- alone and in mixtures with ClO3- was achieved by reaction with I- at pH 2 to liberate I, which was measured spectrophotometrically at 370 nm. Both ClO2- and ClO3- react with I- in 6 M HCl, and the individual species were determined by multiple regression. The calibration graph was rectilinear from 2 to 150 µM-ClO2- and from 2 to 100 µM-ClO3-, with coefficient of variation of 0.4 and 1.2%, respectively. Detection limits were 0.04 mg L-1 for ClO2- and 0.03 mg L-1 for ClO3-. The method was fast and simple and suitable for sub mg L-1 levels in drinking water. Determination of ClO2- alone and in mixtures with ClO3- was achieved by reaction with I- at pH 2 to liberate I, which was measured spectrophotometrically at 370 nm. Both ClO2- and ClO3- react with I- in 6 M HCl, and the individual species were determined by multiple regression. The calibration graph was rectilinear from 2 to 150 µM-ClO2- and from 2 to 100 µM-ClO3-, with coefficient of variation of 0.4 and 1.2%, respectively. Detection limits were 0.04 mg L-1 for ClO2- and 0.03 mg L-1 for ClO3-. The method was fast and simple and suitable for sub mg L-1 levels in drinking water.
Water Spectrophotometry Calibration Detection limit

"Sensitivity Enhancement By Potentiometric Flow Injection Analysis Based On Redox Reaction With An Iron(III) - Iron(II) Buffer"
Anal. Chim. Acta 1992 Volume 261, Issue 1-2 Pages 405-410
Nobuhiko Ishibashi, Toshihiko Imato*, Sumio Yamasaki and Hiroki Ohura

Abstract: For the determination of oxidizing species, the sample solution (200 µL) is injected into water as carrier and the stream is mixed with a reagent solution containing 0.01 M Fe(III) - 0.01 M Fe(II), 0.4 M NaBr and 1.2 M H2SO4 in a 100-cm reaction coil. The resulting solution passes to an oxidation - reduction potential electrode detector (cf. Ibid., 1988, 214, 349) for potentiometric measurement. The transient potential change is rectilinearly related to the concentration. of Cr2O72-, BrO3-, ClO2-, H2O2 or O3 (sensitivities tabulated). Detection limits for the first three species are 0.3 µM, 0.05 µM and 0.1 µM, respectively; the sensitivity towards H2O2 is enhanced by adding 0.5% of (NH4)6Mo7O24 to the reagent solution. A sampling rate of 40 h-1 is attainable. Highly sensitive potentiometric flow injection analysis for oxidative species such as bromate, chlorite, dichromate, hydrogen peroxide and ozone is described, using an Fe(III)-Fe(II) potential buffer containing bromide. The method is based on detection of large transient potential changes of an oxidation-reduction potential electrode which appear in short period after mixing a sample with the potential buffer. This large transient potential change is due to bromine generated by the reaction of the sample with bromide in the potential buffer. Anal. sensitivities obtained by the transient change of potential are enhanced 25-350-fold compared with that using the change in equilibrium. potential. Detection limits of 5 x 10^-8 M for bromate, 1 x 10^-7 M for chlorite and 3 x 10^-7 M for dichromate 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 H2SO4. For the determination of hydrogen peroxide, the addition of ammonium molybdate to the potential buffer accelerates the generation of bromine caused by the reaction of hydrogen peroxide with bromide and thus enhances the sensitivity.
Potentiometry Redox

"Investigation Of Turbomixers In Continuous-flow Analysis"
Talanta 1992 Volume 39, Issue 3 Pages 293-297
T. L. Spinks and G. E. Pacey*L. Fabian, S. Lee and B. P. Bubnis,

Abstract: Turbomixers were studied as replacements for mixing coils in flow injection methods for the determination of O3, ClO2-, ClO3-, Kjeldahl N, NO2- and phosphate. The limits of detection and coefficient of variation were generally comparable with or better than those obtained by standard flow injection analysis and sample throughput was 10% higher. The mixers removed the need for circular, serpentine or knotted coils. This paper describes an investigation of turbomixer as replacements for mixing coils in flow injection analysis (FIA). The turbomixer is a device that will efficiently mix three streams simultaneously. Although the traditional FIA gradient is not produced, the data shows that the reproducibility of a turbomixer-continuous-flow system is comparable to a standard FIA system.
Turbomixers Mixing Method comparison Knotted reactor Kjeldahl

"Determination Of Chlorite And Chlorate In Chlorinated And Chloraminated Drinking Water By Flow Injection Analysis And Ion Chromatography"
Anal. Chem. 1992 Volume 64, Issue 5 Pages 496-502
Andrea M. Dietrich, Tracey D. Ledder, Daniel L. Gallagher, Margaret N. Grabeel, and Robert C. Hoehn

Abstract: The performance of flow injection analysis with iodometric detection (c.f., Miller, ibid., 1985, 57, 734) and ion chromatography with conductometric detection (c.f., Themelis, Anal. Chim. Acta, 1989, 225, 24) for the determination of chlorite and chlorate in drinking water was examined. The accuracy of both methods was similar, but the flow injection analysis method was affected by the presence of oxidants and chloramines; the ion chromatographic method was unaffected by the presence of such compounds. The addition of sodium oxalate and ethylenediamine to the drinking water increased the stability of chlorite to up to 3 and 18 days, respectively. Chlorate was stable in drinking water for up to 18 days, with or without preservative. The determination of CLO2- and ClO3- concentrations in drinking water by flow injection analysis (FIA) with iodometric detection and ion chromatography (IC) with conductivity detection was studied. The FIA and IC methods were accurate and effective for reagent water. The IC method was accurate for measurement of ClO2- and ClO3- concentrations in drinking water even in the presence of other oxidants including chloramines. However, FIA was affected by chloramines and other oxidants in drinking water, resulting in inaccurate determinations While ClO2- concentrations were unstable in chlorinated drinking water, addition of sodium oxalate increased the stability to 3 days and addition of ethylenediamine increased stability to 18 days. ClO3- concentrations were stable in drinking water for 18 days with or without a preservative.
Water HPIC Interferences Method comparison