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

• Published in: Analytical and bioanalytical chemistry 2016-02, Vol.408 (6), p.1701-1713
• Main Authors: Liang, Ning, Huang, Peiting, Hou, Xiaohong, Li, Zhen, Tao, Lei, Zhao, Longshan
• Format: Article
• Language: English
• Subjects: acetonitrile; Acetonitriles; Analytical Chemistry; Anti-Bacterial Agents - analysis; Antibiotics; Biochemistry; Calibration; cefuroxime; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; chloramphenicol; Chromatography; Chromatography, High Pressure Liquid - methods; ciprofloxacin; doxycycline; Drinking Water - analysis; Food Science; Hydrogen-Ion Concentration; Laboratory Medicine; levofloxacin; Limit of Detection; Liquid chromatography; Liquid Phase Microextraction - methods; Liquid-liquid extraction; liquid-phase microextraction; Liquids; Mass spectrometry; Methanol; Methanol - chemistry; Methyl alcohol; methylene chloride; Monitoring/Environmental Analysis; oxytetracycline; Research Paper; Rivers - chemistry; Scientific imaging; solid phase extraction; Solid Phase Extraction - methods; Solvents; Solvents - chemistry; sulfadiazine; sulfamethoxazole; tandem mass spectrometry; Tandem Mass Spectrometry - methods; tetracycline; Tetracyclines; tinidazole; Waste Water - analysis; Water analysis; Water Pollutants, Chemical - analysis; Water sampling
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-015-9284-z

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.