Analytical Sciences


Abstract − Analytical Sciences, 22(2), 333 (2006).

Kinetic Spectrophotometric Method for the Determination of Trace Amounts of Oxalate by an Activation Effect
Mansour Arab CHAMJANGALI, Vahid KELEY, and Ghadamali BAGHERIAN
College of Chemistry, Shahrood University of Technology, Shahrood 36155-316, Iran
A new, simple and inexpensive kinetic catalytic spectrophotometric method for the determination of oxalate is described. The method is based on an activation effect of oxalate on a catalytic effect of iron(II) on the oxidation of iodide by bromate. The reaction is monitored by measuring the absorbance of triiodide ion at λmax = 352 nm. A calibration graph was obtained from 0.10 - 7.0 µg cm-3 of oxalate with a detection limit of 0.080 µg cm-3. The standard deviations for ten replicate determinations of 0.50, 1.0 and 5.0 µg cm-3 of oxalate were 4.0, 2.6 and 1.8%, respectively. The applicability of the method was demonstrated by the determination of oxalate ion in real samples.