title: Aqueous two-phase systems: a new approach for the determination of p-aminophenol.
abstract: A new method has been developed for the spectrophotometric determination of p-aminophenol (PAP) in water, paracetamol formulations and human urine samples with a recovery rate between 94.9 and 101%. This method exploits an aqueous two-phase system (ATPS) liquid-liquid extraction technique with the reaction of PAP, sodium nitroprusside and hydroxylamine hydrochloride in pH 12.0, which produces the [Fe(2)(CN)(10)](10-) anion complex that spontaneously concentrates in the top phase of the ATPS ([Formula in text]). The ATPS does not require an organic solvent, which is a safer and cleaner liquid-liquid extraction technique for the determination of PAP. The linear range of detection was from 5.00 to 500 μg kg(-1) (R ≥ 0.9990; n=8) with a coefficient of variation of 2.11% (n=5). The method exhibited a detection limit of 2.40 μg kg(-1) and a quantification limit of 8.00 μg kg(-1). The ATPS method showed a recovery that ranged between 96.4 and 103% for the determination of PAP in natural water and wastewater samples, which was in excellent agreement with the results of the standard 4-aminoantipyrine method that was performed on the same samples.
authors.affiliation: Grupo de Química Verde Coloidal e Macromolecular, Departamento de Química, Centro de Ciências Exatas e Tecnológicas, Universidade Federal de Viçosa, Av. P.H. Rolfs s/n, Viçosa, MG 36560-000, Brazil.
authors.forename: Guilherme Dias
authors.initials: GD
authors.lastname: Rodrigues
authors.forename: Leandro Rodrigues
authors.initials: LR
authors.lastname: de Lemos
authors.forename: Pamela da Rocha
authors.initials: Pda R
authors.lastname: Patrício
authors.forename: Luis Henrique Mendes
authors.initials: LH
authors.lastname: da Silva
authors.forename: Maria do Carmo Hespanhol
authors.initials: Mdo C
authors.lastname: da Silva
mesh_terms: D000627:Aminophenols / Q000032:analysis*; D057230:Limit of Detection; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000627:Aminophenols; C026729:4-aminophenol