Sistemas aquosos bifásicos: Uma nova abordagem para a determinação de p-aminofenol

• Autor(a) principal: Lemos, Leandro Rodrigues de
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2124
• topic: Sistemas aquosos bifásicos; p-aminofenol; Paracetamol; Urina humana; Aqueous two phase system; p-aminophenol; Paracetamol; Human urine; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

This work initially presents a brief review of aqueous two-phase systems (ATPS), and analytical methodologies for PAP determination with emphasis in spectrophotometric techniques. A new method has been developed for the spectrophotometric determination of p aminophenol (PAP) in water, formulations of paracetamol and human urine. The procedure exploits an aqueous two phase system (ATPS) liquid liquid extraction technique and the reaction of PAP, sodium nitroprusside (NPS) and hydroxylamine hydrochloride (HL) in an alkaline medium (pH 12.0), producing the complex anion [Fe2(CN)10]10 that spontaneously concentrates in the top phase of the system ( 10− [Fe2 (CN)10 ] K = 97.7). The ATPS is formed mostly by water and does not require organic solvent. The other components of the ATPS were polymer, polyethylene oxide, and salts (i.e., Li2SO4, Na2SO4 or K2HPO4 + KOH). The linear range was 5.00 to 500 μg kg 1 (R ≥ 0.9990; n = 8) with coefficients of variation of 2.11 % (n = 5). The method exhibited a limit of detection (LOD) of 2.40 μg kg 1 and a limit of quantification (LOQ) of 8.00 μg kg 1. The ATPS method showed recoveries between 96.4 103 % for the determination of PAP in natural water and wastewater samples, in excellent agreement with the results of the standard 4 aminoantipyrine (4- AAP) method for the same samples. The proposed method was also used for the determination of PAP in paracetamol pharmaceutical formulations and human urine samples with recovery rates between 94.9 101 %.