title: Preconcentration of polar phenolic compounds from water samples and soil extract by liquid-phase microextraction and determination via liquid chromatography with ultraviolet detection.
abstract: This work proposes a liquid-phase microextraction (LPME) method to extract the highly polar compounds phenol (Ph), o-cresol (o-Cr), m-cresol (m-Cr), p-cresol (p-Cr), and 2,4-dimethylphenol (2,4-DMP) from aqueous matrices. The first extraction step of the LPME method employed a common volumetric flask and n-octanol, and the second extraction step used NaOH as the acceptor phase. The optimized extraction conditions were 900 μL of n-octanol as the extraction solvent, NaOH at 0.60 mol L(-1) as the acceptor phase, an extraction time of 5.0 min, HCl at 0.01 mol L(-1) and NaCl at 20.0% as the donor phase, and an extraction temperature of 20.0°C. The analysis of 50.0 mL of aqueous sample, pretreated under the optimized LPME conditions, afforded a limit of detection (LOD) between 0.3 and 3.5 μg L(-1), a limit of quantification (LOQ) between 1.2 and 11.6 μg L(-1), and a linear range from 2.50 to 50.0 μg L(-1) for Ph, o-Cr, m-Cr and p-Cr and from 12.5 to 250 μg L(-1) for 2,4-DMP. The proposed LPME method was a successful sample preparation strategy, and allowed for precise and accurate quantification of polar phenolic compounds in aqueous matrices such as tap water, river water, groundwater, and seawater, and also in a soil extract. The recovery values ranged from 72.5% to 126.0%, and the relative standard deviation was between 0.3 and 11.5%.
authors.affiliation: Departamento de Química, Universidade Federal do Paraná, CP 19032, CEP 81531-990, Curitiba, PR, Brazil.
authors.forename: Rafael Garrett
authors.initials: RG
authors.lastname: Dolatto
authors.affiliation: Departamento de Química, Universidade Federal do Paraná, CP 19032, CEP 81531-990, Curitiba, PR, Brazil.
authors.forename: Iara
authors.initials: I
authors.lastname: Messerschmidt
authors.affiliation: FAPEG/Embrapa Clima Temperado, BR 392, Km 78, CEP 96010-971, Pelotas, RS, Brazil.
authors.forename: Betânia Fraga
authors.initials: BF
authors.lastname: Pereira
authors.affiliation: Embrapa Clima Temperado, BR 392, Km 78, CEP 96010-971, Pelotas, RS, Brazil.
authors.forename: Rosane
authors.initials: R
authors.lastname: Martinazzo
authors.affiliation: Departamento de Química, Universidade Federal do Paraná, CP 19032, CEP 81531-990, Curitiba, PR, Brazil. Electronic address: gilberto@quimica.ufpr.br.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Abate
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D005618:Fresh Water / Q000032:analysis*; D059627:Liquid Phase Microextraction / Q000379:methods*; D010636:Phenols / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014874:Water Pollutants, Chemical / Q000819:agonists*
chemical_list: D010636:Phenols; D012987:Soil; D014874:Water Pollutants, Chemical
keywords: Cresols; Phenol; Preconcentration; Soil extract; Solvent microextraction; Waters