KINETIC SPECTROPHOTOMETRIC DETERMINATION OF IRIDIUM WITH DIANTIPYRYLPHENYLMETHANE DERIVATIVES

ABSTRACT

The catalytic effects of iridium on the oxidation reactions of three new diantipyrylphenylmethane derivatives: diantipyryl-(o-bromo)phenylmethane (DAoBM), diantipyryl-(m-bromo) phenylmethane (DAmBM) and diantipyryl-(p-bromo) phenylmethane (DApBM), by KIO₄ are investigated spectrophotometrically and applied for the kinetic determination of iridium(IV) in HCl medium at 90 ± 0.5°C. The above reactions are monitored spectrophotometrically by measuring the increase in the absorbance at 485, 490 and 485 nm for the catalytic reactions of DAoBM, DAmBM and DApBM, respectively. The working curves for the three recommended reaction-rate methods are linear in the concentration range over 0.5–40, 1.0–40, and 1.0–50 µg/L with the detection limit of 0.49, 0.71 and 0.90 µg/L for DAoBM, DAmBM and DApBM methods, respectively. No foreign ions except for Ru(III) interfered in the determination at the concentration less than 5-fold amount of Ir(IV). The methods are of high sensitivity, good selectivity and stability, and have been successfully applied for the determination of trace amount of iridium in some ore and metallurgy products.

Keywords:

• Iridium(III)
• Kinetic spectrophotometry
• Periodate
• Diantipyrylphenylmethane derivatives

Acknowledgments