[1] UNL, REQUIMTE CQFB, Fac Ciencias & Tecnol, Dep Quim, P-2829516 Caparica, Portugal
[2] PETROBRAS CENPES, BR-21941915 Rio De Janeiro, RJ, Brazil
[3] Pontificia Univ Catolica Rio Grande do Sul, Fac Quim, BR-90619900 Porto Alegre, RS, Brazil
[4] Inst Quim UFRGS, Porto Alegre, RS, Brazil