title: Solid-phase extraction in combination with dispersive liquid-liquid microextraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis: the ultra-trace determination of 10 antibiotics in water samples.
abstract: A novel method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was developed for ultra-preconcentration of 10 antibiotics in different environmental water samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry detection. The optimized results were obtained as follows: after being adjusted to pH 4.0, the water sample was firstly passed through PEP-2 column at 10 mL min(-1), and then methanol was used to elute the target analytes for the following steps. Dichloromethane was selected as extraction solvent, and methanol/acetonitrile (1:1, v/v) as dispersive solvent. Under optimal conditions, the calibration curves were linear in the range of 1-1000 ng mL(-1) (sulfamethoxazole, cefuroxime axetil), 5-1000 ng mL(-1) (tinidazole), 10-1000 ng mL(-1) (chloramphenicol), 2-1000 ng mL(-1) (levofloxacin oxytetracycline, doxycycline, tetracycline, and ciprofloxacin) and 1-400 ng mL(-1) (sulfadiazine) with a good precision. The LOD and LOQ of the method were at very low levels, below 1.67 and 5.57 ng mL(-1), respectively. The relative recoveries of the target analytes were in the range from 64.16% to 99.80% with relative standard deviations between 0.7 and 8.4%. The matrix effect of this method showed a great decrease compared with solid-phase extraction and a significant value of enrichment factor (EF) compared with dispersive liquid-liquid microextraction. The developed method was successfully applied to the extraction and analysis of antibiotics in different water samples with satisfactory results.
authors.affiliation: School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liang
authors.affiliation: School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
authors.forename: Peiting
authors.initials: P
authors.lastname: Huang
authors.affiliation: School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Hou
authors.affiliation: School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Tao
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, 110016, China. longshanzhao@163.com.
authors.forename: Longshan
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000097:Acetonitriles; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D060766:Drinking Water / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D000432:Methanol / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000097:Acetonitriles; D000900:Anti-Bacterial Agents; D060766:Drinking Water; D000432:Methanol; D012997:Solvents; D062065:Wastewater; D014874:Water Pollutants, Chemical; C032159:acetonitrile
keywords: Antibiotics; Dispersive liquid-liquid microextraction; Solid-phase extraction; Ultra-high performance liquid chromatography-tandem mass spectrometry; Water samples