Abstract

High-pressure homogenisation of softwood pulp fibres was evaluated as a sample preparation procedure prior to Cu, Fe and Mn determination by electrothermal atomic absorption spectrometry. Although homogenisation in tetramethylammonium hydroxide proved to be unsuitable, fibres that had been pre-swollen with aqueous zinc chloride were readily homogenized to result in slurries that provided repeatable estimates of analyte concentrations, which were analogous to estimates obtained from solutions prepared by conventional or microwave-assisted digestion with strong oxidants. The release of analytes into the aqueous phase however was incomplete, even with the addition of EDTA or DTPA complexing reagents to the crude fibre suspension or cellulase plus xylanase-assisted digestions of the suspension post-homogenisation. The advantages of this procedure for sample preparation included time saving and decreased operator intervention. Sample preparation was completed in 5 min.