Atomic Absorption Spectrometric and Synergistic Spectrophotometric Microdetermination of Hafnium in Alloys and Environmental Samples

Abstract

Hafnium (IV) was selectively extracted from 0.45–0.55 M HC1 media as its chelate with N-p-methoxyphenyl-2-furylacrylo-hydroxamic acid (MFHA) into chloroform. Xylenol orange was added to the extract to form an intensely coloured ternary complex measurable spectrophotometrically at 545 nm (∊ = 8.3×10⁴1 mol⁻¹ cm⁻¹) with a sensitivity better than 0.002 ppm. For atomic absorption spectrometric determination, hafnium was extracted with MFHA into methyl isobutyl ketone and measured with 286.6 nm resonance line in the nitrous oxide-acetylene flame. The methods were applied to the analysis of hafnium in alloys, plant tissues, animal tissues and natural waters. The MFHA-xylenol orange reagent combination was chosen after studying ten hydroxamic acids and five chromogenic reagents.

Key Words:

• AAS
• Environment
• Extraction
• Hafnium
• Spectrophotometry