Selective Extraction of Zirconium from Various Samples and Subsequent Spectrophotometric Determination with Eriochrome Cyanine R Reagent

Hanan H Ahmad,Salim A Mohammed

doi:10.33899/rjs.2009.40231

Abstract

A sensitive and selective spectrophotometric method for the determination of zirconium(IV) in various samples has been developed. In this method trioctylphosphine oxide (TOPO) is used for the extraction of zirconium. The colour of the complex is developed in the organic phase by the addition of eriochrome cyanine R reagent (ECR) and ethanol as a diluent. The calibration plot is linear in the concentration range 0.08–10 μg ml-1 with a molar absorptivity (ε) of 2.0x104 l.mol-1 cm-1 at 564 nm The stoichiometric composition of the chelate is 1:2 ( Zr : ECR ). The extraction of zirconium (IV) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. The proposed method was successfully used for the determination of zirconium in various samples such as, natural waters and ores .

Highlights

Zirconium is widely distributed in nature .The principal ores are zircon (ZrO2.SiO2 ) and elipidite (Na2ZrSi6O15.3H2O )
A large number of spectrophotometric methods have been used for assay of zirconium in rocks, water and minerals, mineral water, industrial water, zirconium and magnesium alloys, using arsenazo III (Changfa, 1988), alizarin–red S ( Hassanien 2005), 2,4-dihydroxy benzaldehyde isonicotinoyl hydrazone (Sivaramaiah et al, 2003), 3,4-dihydroxyazobenzene (Vilkova and Invanov, 1989), and 1-(2-pyridylazo)-2naphthol (PAN) (Ysumaso and Takehiro, 1981) as reagents, respectively
In order to increase the selectivity, a reliable separation technique like solvent extraction is necessary before the spectrophotometric determination of zirconium by eriochrome cyanine R reagent (ECR)

Summary

Introduction

Zirconium is widely distributed in nature .The principal ores are zircon (ZrO2.SiO2 ) and elipidite (Na2ZrSi6O15.3H2O ). In order to increase the selectivity, a reliable separation technique like solvent extraction is necessary before the spectrophotometric determination of zirconium by ECR. The extraction of zirconium from different acidic media by TOPO solution in cyclohexane or acetophenone and subsequent spectrophoto-metric determination with PAN reagents using methanol as a solvent has been investigated (Ysumaso and Takehiro, 1981) .

Results

Conclusion