title: Systematic optimization of an SPE with HPLC-FLD method for fluoroquinolone detection in wastewater.
abstract: This paper describes a selective and ultra-sensitive analytical method for simultaneous determination of 11 fluoroquinolone (FQ) antibiotics in environmental and wastewater samples. The method employs offline solid-phase extraction (SPE) and reversed-phase high performance liquid chromatography with fluorescence detection (HPLC-FLD). A weak cation exchange SPE protocol was developed with a novel loading volume optimization algorithm and a methanol cleanup step to remove background organic matter. Various parameters were optimized to recover FQs from water/wastewater and analyte recovery was generally greater than 80%. Chromatographic separation of the 11 FQs was achieved on a 150 mm pentafluorophenyl column using a gradient elution scheme with methanol, acetonitrile, and 20mM phosphate buffer (pH=2.4). Excitation and emission wavelengths were individually optimized for each FQ using fluorescence spectroscopy; the excitation and emission wavelengths were 276-296 nm and 444-506 nm, respectively. Instrumental quantitation limits were 20-100 pg of mass injected. Of the 11 FQs investigated, seven (i.e., ciprofloxacin, difloxacin, enrofloxacin, fleroxacin, norfloxacin, moxifloxacin, and ofloxacin) were detected during a four-month sampling campaign of wastewater and wastewater-impacted surface water. Concentrations of FQs in raw wastewater, wastewater effluent, and wastewater-impacted surface water were 5-1292, 2-504, and 4-187ng/L, respectively.
authors.affiliation: University of Maryland Baltimore County, Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, United States.
authors.forename: Ke
authors.initials: K
authors.lastname: He
authors.affiliation: University of Maryland Baltimore County, Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, United States. Electronic address: blaney@umbc.edu.
authors.forename: Lee
authors.initials: L
authors.lastname: Blaney
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004784:Environmental Monitoring; D005453:Fluorescence; D024841:Fluoroquinolones / Q000032:analysis*; D008396:Maryland; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Fluorescence detection; Fluoroquinolones; HPLC; PPCPs; SPE; Wastewater