Anions in non saline waters - Determination of Anions in Natural and Treated Waters - page 182

selective iodide electrodes. This electrode demonstrates excellent selectivity to iodine.
The selectivity sequence is I>CNS>NO 2 > ClO 4 >Br>NO 3 >Cl>SO 4 .
Various other workers [134,344,367,368] have used an iodide-ion electrode for the
determination of iodide in non saline waters. Butler and Gershey [344] used an iodide-
selective electrode to measure down to InM iodide separated from other anions by ion
exchange high performance liquid chromatography. Nakayama and Kimoto [368] used a
flow-through electrode system. Weiss [134] determined both iodides and cyanides in
micromole quantities using an iodide-selective electrode.

2.50.11 Neutron activation analysis
Malvano et al. [369] determined iodide in water by this technique and compared results
obtained with those obtained by the autoanalysed spectrometric method.

2.50.12 Isotope dilution analysis
This technique combined with mass spectrometry has been used to determine down to
0.1µg L −1 iodide in non saline waters [370].

2.50.13 Ion chromatography
Dils and Smeenk [371] have discussed the determination of iodide and phosphate in non
saline waters.

2.50.14 High performance liquid chromatography
Moss and Stephen [139] determined iodide, bromide and chloride in non saline waters by
conversion to alkyl mercury(II) halide and measurement by high performance liquid
chromatography.
Stetzenbach and Thompson [138] employed high performance liquid chromatography
on anion exchange columns to determine iodide in admixture with chloride, bromide,
nitrate and thiocyanate in non saline water.
Iodide in non saline waters has been determined [344] by ion exchange high
performance liquid chromatography using an iodide ion selective electrode as a detector.
On-line preconcentration of iodide on an anion guard cartridge allowed determinations
down to 1n mol L −1 .
Verma et al. [372] determined iodide in non saline waters by high performance liquid
chromatography after precolumn derivatisation of iodide to 4-iodo-2,6-dimethylphenol.
The derivative was detected by an ultraviolet detector. Down to 2µg L −1 iodide can be

determined by this procedure.
The application of this technique is also discussed under multianion analysis in
sections 13.1.1.2, 13.1.1.3, 13.1.1.4 and 13.1.1.7.

2.50.15 Micelle chromatography
Okada [350] has used micelle exclusion chromatography to determine iodide in the