Determination of lead by electrothermal atomic absorption spectrometry employing a novel sampling strategy of polyurethane foam impregnated with thiazolylazo-p-cresol (TAC)

This work presents a method for lead determination by ETAAS, based on solid sampling of polyurethane foam (PUF) impregnated with the reagent 2-(2-thiazolylazo)-p-cresol (TAC) previously utilized to extract the metallic ion from sample solution. The extraction process occurred in a medium buffered in pH 10 with borate system, after 40 min of agitation between the solid and liquid phases. The obtained results showed the easily elimination of the matrix from the graphite tube by a pyrolysis step at 600 ºC, without using of any matrix modifier. The method was validated by analysis of certified materials (biological samples) and by using recovery tests employing saline samples.

solid phase extraction; polyurethane foam; thiazolylazo-p-cresol; solid sampling technique; lead; ETAAS