Aqueous two-phase systems: A new approach for the determination of p-aminophenol

• Published in: Journal of hazardous materials 2011-08, Vol.192 (1), p.292-298
• Main Authors: Rodrigues, Guilherme Dias, Lemos, Leandro Rodrigues de, Patrício, Pamela da Rocha, Silva, Luis Henrique Mendes da, Silva, Maria do Carmo Hespanhol da
• Format: Article
• Language: English
• Subjects: Aminophenols - analysis; Anions; Applied sciences; Aqueous two-phase system; ATP; Chemical engineering; Clean method; Exact sciences and technology; General purification processes; Hazardous materials; Limit of Detection; Liquid-liquid extraction; p-Aminophenol; Pollution; Recovery; Sodium; Solvents; Spectrophotometry, Ultraviolet; Waste; Waste water; Wastewaters; Water; Water treatment and pollution
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.05.023

► A green chemistry method to analyze p-aminophenol in different samples was developed. ► It is a simple spectrophotometric, very sensitivity and low cost method. ► Due to transfer process between two phases the method has little interference. ► The new procedure has good agreement with the results of the 4-aminoantipyrine method. 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 ( K [ Fe 2 ( CN ) 10 ] 10 − = 97.7 ). 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.