title: Simultaneous determination of five nitroaniline and dinitroaniline isomers in wastewaters by solid-phase extraction and high-performance liquid chromatography with ultraviolet detection.
abstract: A high-performance liquid chromatography (HPLC)-ultraviolet detection method, combined with solid-phase extraction (SPE), was developed for the determination of five nitroaniline and dinitroaniline isomers including 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline and 2,6-dinitroaniline in wastewater samples. Extraction of the five isomers was carried out with a hydrophile-lipophile balance cartridge, the Oasis HLB. The cartridge was washed by a mixed aqueous solution containing 10% (v/v) acetonitrile and 10% (v/v) ethyl acetate before the five isomers were eluted by a mixture of methanol and acetic acid. Separation of the five isomers was achieved by using an Agilent TC-C(18) column at 30°C, and using a mixture of acetonitrile/water 30/70 (v/v) as mobile phase under an isocratic condition at a flow rate of 1.0 mL/min. The analytes were detected by a UV detector at a wavelength of 225 nm. Recoveries of the five isomers in the spiked sewage sample were between 84.6% and 94.0% with a relative standard deviation of less than 4.7%. The limits of quantification (LOQ) determined in a spiked sewage sample of 500 mL were 2.0 x 10(-9)M for 2-nitroaniline, 3-nitroaniline and 2,6-dinitroaniline, and 4.5 x 10(-9)M for 4-nitroaniline and 2,4-dinitroaniline. The proposed method was applied to determine the five isomers in real samples of acidic wastewater and printing and dyeing wastewater.
authors.affiliation: MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China. cltong@zju.edu.cn
authors.forename: Changlun
authors.initials: C
authors.lastname: Tong
authors.forename: Yun
authors.initials: Y
authors.lastname: Guo
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu
mesh_terms: D000814:Aniline Compounds / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D007536:Isomerism; D052616:Solid Phase Extraction; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D000814:Aniline Compounds; D014874:Water Pollutants, Chemical; C019498:4-nitroaniline; C008625:nitroaniline; C010934:2,4-dinitroaniline; C403062:3-nitroaniline