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

Abstract

Este trabalho apresenta um método para a determinação de chumbo por ETAAS, baseado na amostragem sólida da espuma de poliuretano impregnada com o reagente 2-(2-tiazolilazo)-p-cresol (TAC) previamente utilizada para extrair o íon metálico da solução amostra. O processo de extração ocorreu em pH 10, tamponado com sistema borato, após 40 min de agitação das fases sólida e líquida. Os resultados obtidos mostraram a fácil eliminação da matriz do tubo de grafite, utilizando como pirólise a temperatura de 600 ºC, sem a adição de modificador químico de matriz. O método desenvolvido foi validado através da análise de materiais certificados de referência (amostras biológicas) e através de testes de recuperação em amostras salinas. 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.

Preconcentration system for cadmium and lead determination in environmental samples using polyurethane foam/Me-BTANC

“…Polyurethane foam has been used unloaded or associated to physically immobilised chelating reagents in preconcentration and sampling procedures [19,20].…”

Removal of Malachite Green from Aqueous Medium Employing Polyurethane Foam as Adsorbent and Sodium Dodecylsulfate as Carrier

“…Since then, PUF has been used as a solid sorbent to separate and preconcentrate a wide variety of inorganic and organic substances from different media (Moody and Thomas 1982). PUF can be directly used without previous treatment (Cassella et al 2000;Farag and El-Shahawi 1991;El-Shahawi and Al-Daheri 1996;Almeida et al 2007;Cassella et al 1999) or modified by the addition or loading of several chelating agents, liquid ion exchangers, or other substances (Alexandrova and Arpadjan 1995;Sant'Ana et al 2004;Cassella et al 2001;Braun et al 1973;Braun and Farag 1972).…”

Characterization of solid-phase extraction of Fe(III) by unloaded polyurethane foam as thiocyanate complex

“…In this context, the work of Hasany et al [18] reports the kinetic and chemical characterization of sorption of Co-SCN − complexes by open cell polyurethane foam, while Sant'Ana et al [19][20][21] have characterized the sorption of some metallic cations onto PUF loaded with different organic chelating agents.…”