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.

Phase diagrams, densities and refractive indexes of poly(ethylene oxide)+organic salts+water aqueous two-phase systems: Effect of temperature, anion and molar mass

“…Aqueous two-phase system (ATPSs) have been used for the extraction, separation and purification of solutes such as proteins [1], enzymes [2], amino acids [3], antibiotics [4], nucleic acids [5], ions [6][7][8][9], nanomaterials [10], and organic molecules [11][12][13].…”

Copper recovery from ore by liquid–liquid extraction using aqueous two-phase system

“…The triblock copolymer used in this study was poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), L35, with an average molar mass (M m ) of 1900 g mol −1 and 50% ethylene oxide, corresponding to a composition of (EO) 11 (PO) 16 (EO) 11 …”

“…The ATPS has several advantages, including its easy operation, low-cost and the possibility to recycle its components [10]. These systems have been used for the separation, preconcentration, purification and determination of biomolecules [11][12][13][14], phenols [15,16], dyes [17] and metallic ions [6][7][8]18]. Factors such as the pH, the design of the system, the electrolyte composition, the temperature and the extractant concentration strongly affect the partitioning behavior and the separation of analytes [19].…”

Platinized agarose microspheres as a new modifier in graphite paste electrodes for the electrochemical determination of 4-aminophenol

“… 3 Therefore, it is necessary to develop simple and reliable methods for determination of 4-AP, for environmental protection and food security. Many attempts, therefore, have been made to develop an efficient and selective way of determining 4-AP, such as liquid chromatography, 4,5 spectrophotometry, 6 sequential injection analysis, 7 capillary electrophoresis, 8 and micellar electrokinetic chromatography. 9 However, use of these techniques suffer because they are expensive and have a long analysis time.…”