Determination of Trace Boron in Iron and Steel by Adsorptive Stripping Voltammetry using Beryllon III
Adsorptive stripping voltammetry is proposed for determination of boron at low μg g<sup>−1</sup> level in iron and steel. Beryllon III was used as a complexing agent for boron(III). Optimum conditions for the formation of the boron(III)–Beryllon III complex were as follows: 0.06 M nitrate–0.04 M sulfate supporting electrolyte at pH 4.5; 1.0×10<sup>−5</sup> M Beryllon III; 24 h complexation time. The complex was accumulated on a hanging mercury drop electrode at −0.35 V <i>vs.</i> SCE for 60 s under stirring, and was subsequently cathodically stripped to −0.8 V <i>vs</i>. SCE at a scan rate of 10 mV s<sup>−1</sup> using a differential pulse mode. Interference by iron(III) was eliminated by the complexation with metaphosphoric acid. After cathodic stripping, a single well-defined peak was observed at around −0.5 V <i>vs.</i> SCE. The influence of foreign elements on the determination was also evaluated. The calibration graph (peak height <i>vs.</i> boron(III) concentration) in the presence of 1 mg mL<sup>−1</sup> iron(III) was linear over a concentration range of 1–25 ng mL<sup>−1</sup> (correlation coefficient >0.999), with a relative standard deviation (<i>n</i>=4) of 2.6% at 10 ng mL<sup>−1</sup>. The minimum limit of determination was 1 μg g<sup>−1</sup> of boron in iron and steel. The proposed method has been proved to be applicable to the determination of trace boron in iron and steel with good precision and accuracy.
- ISIJ international
ISIJ international 46(9), 1318-1323, 2006-09-15
The Iron and Steel Institute of Japan