title: Determination of octylphenol and nonylphenol in aqueous sample using simultaneous derivatization and dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.
abstract: A simple and fast sample preparation method for the determination of nonylphenol (NP) and octylphenol (OP) in aqueous samples by simultaneous derivatization and dispersive liquid-liquid microextraction (DLLME) was investigated using gas chromatography-mass spectrometry (GC/MS). In this method, a combined dispersant/derivatization catalyst (methanol/pyridine mixture) was firstly added to an aqueous sample, following which a derivatization reagent/extraction solvent (methyl chloroformate/chloroform) was rapidly injected to combine in situ derivatization and extraction in a single step. After centrifuging, the sedimented phase containing the analytes was injected into the GC port by autosampler for analysis. Several parameters, such as extraction solvent, dispersant solvent, amount of derivatization reagent, derivatization and extraction time, pH, and ionic strength were optimized to obtain higher sensitivity for the detection of NP and OP. Under the optimized conditions, good linearity was observed in the range of 0.1-1000 μg L⁻¹ and 0.01-100 μg L⁻¹ with the limits of detection (LOD) of 0.03 μg L⁻¹ and 0.002 μg L⁻¹ for NP and OP, respectively. Water samples collected from the Pearl River were analyzed with the proposed method, the concentrations of NP and OP were found to be 2.40 ± 0.16 μg L⁻¹ and 0.037 ± 0.001 μg L⁻¹, respectively. The relative recoveries of the water samples spiked with different concentrations of NP and OP were in the range of 88.3-106.7%. Compared with SPME and SPE, the proposed method can be successfully applied to the rapid and convenient determination of NP and OP in aqueous samples.
authors.affiliation: State Key Laboratory of Biocontrol/MOE Key Laboratory of Aquatic Product Safety, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Shusheng
authors.initials: S
authors.lastname: Luo
authors.forename: Ling
authors.initials: L
authors.lastname: Fang
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wang
authors.forename: Hongtao
authors.initials: H
authors.lastname: Liu
authors.forename: Gangfeng
authors.initials: G
authors.lastname: Ouyang
authors.forename: Chongyu
authors.initials: C
authors.lastname: Lan
authors.forename: Tiangang
authors.initials: T
authors.lastname: Luan
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002725:Chloroform / Q000737:chemistry; D052244:Endocrine Disruptors / Q000032:analysis* / Q000737:chemistry; D005561:Formates / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D009994:Osmolar Concentration; D010636:Phenols / Q000032:analysis* / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D052244:Endocrine Disruptors; D005561:Formates; D010636:Phenols; D014874:Water Pollutants, Chemical; C474055:octylphenol; C025256:nonylphenol; D002725:Chloroform; C014667:methyl chloroformate