Catalytic titration of iodide, bromide and thiocyanate by use of the silver catalysed phloxin-persulphate reaction.
A method for the catalytic titrimetric determination of iodide, bromide and thiocyanate is described, based on the inhibitory effect of these anions on the silver-catalysed oxidation of phloxin by persulphate in the presence of 2,2'-bipyridyl. The end-point is determined photometrically by measuring the absorbance at 537 nm. Amounts of iodide, bromide and thiocyanate in the 0.01-7.94, 0.11-4.73 and 0.12-3.59mg ranges, respectively, are titrated with a relative error of about 1%.
Sanchez-Pedreño
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Department of Analytical Chemistry, University of Murcia, Murcia, Spain.
Cordoba
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Viñas
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