Simple and Selective Determination of Zr (IV) with 1,4- dichloro-2, 5-dihydroxyquinone in a Micellar Solution of Cetylpyridenium Chloride by Zero and Second-Derivative Spectrophotometry

Abstract

A rapid, simple, selective, and sensitive method for trace determination of Zr (IV) has been
developed based on the reaction of 1,4-dichloro-2,5-dihydroxyquinone in a hydrochloric
acid medium to form a colored complex which is rendered water soluble by the micellar
action of cetylpyridinium chloride (CPC) and measured at λmax 331 nm. Beer's law is obeyed
in the concentration range 0–5 µg.ml-1
. The molar absorptivity of the complex, є was found
to be 1.6 ×104 L.mol -1 cm–1 and Sandell's sensitivity was found to be 5.7 ng.cm–2
. A method
for determination of Zr (IV) by second derivative spectrophtometry has also been proposed.
The detection limit of Zr (IV) in the derivative method is 6 times lower than that of the zero
order method, which shows the higher sensitivity of the derivative method. The method has
been applied for determination of Zr (IV) in various samples, and satisfactory results have
been obtained.