Transactions of the INDIAN CERAMIC SOCIETY Vol. 39 1980
Stabilization and Sensitization of Ferric Thiocyanate
Colour for Determination of Trace Amount
of Iron in Zinc Oxide and other Zinc Minerals
R. SEN AND B. c. SINHA
Pages : 40-44
DOI : 10.1080/0371750X.1980.10840720
Abstract
The effect of various ketones and ketonic mixtures on
the stability and sensitivity of ferric thiocyanate colour in
aqueous solution has been systematically studied. Maximum
increase in intensity (about 2 times) and stability
(more than 4 hours) of the coloured complex has been observed
in aqueous solution containing a mixture of methyl
ethyl ketone and acetone in the ratio from 2:1 to 1 :2 and
having an overall pH from 1.4 to 1.7. Below pH 1.4, the
ferric thiocyanate colour separates out in the upper layer
of the solution while its stability and intensity of colour
decrease with the increase of pH above 2. 7. Large amounts
of zinc which interfere with the determination of iron by
orthophenanthroline method do not have any adverse effect
on the ferric thiocyanate colour. Based on these observations,
a simple and sensitive procedure has been worked out
for determination of small amounts of iron in zinc oxide
and other zinc minerals.
