Solvent-free microwave-assisted extraction of fluoroquinolones from soil and liquid chromatography-fluorescence determination.
Presented hereafter is a novel method entailing solvent free microwave-assisted extraction (MAE) and HPLC equipped with Fluorimetric Detector (HPLC-FD) for the simultaneous determination at μgkg(-1) concentration of eight fluoroquinolone antibiotics (FQs) (Ciprofloxacin, Danofloxacin, Enrofloxacin, Flerofloxacin, Levofloxacin, Marbofloxacin, Norfloxacin and Orbifloxacin) in agricultural soils. The extraction was quantitatively performed, in a single step, by using an aqueous solution containing Mg(II) as complexing agent, thus avoiding consumption of organic solvents. The optimal MAE conditions have been established through a chemometric approach by considering temperature, irradiation time and matrix moisture or solvent, as the most important recognized variables affecting the extraction yield. Satisfying recoveries (69-110%, spikes 0.03-0.5mgkg(-1)) were gained with a single MAE cycle of 20min, at 80°C in 20% (w/v) Mg(NO(3))(2) solution as leaching agent. MAE-SPE recoveries at 10μgkg(-1), concentration near method quantification limits (MQLs), were in the range 60-85%. Good repeatability and within-lab reproducibility were observed (both in the range 1-16%). The applicability of the method to real samples was assessed on natural contaminated soils. Compared to ultrasonic-assisted extraction (UAE), MAE was shown to be highly competitive in terms of extraction efficacy and analysis speed.
Department of General Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy.
Michela
M
Sturini
Andrea
A
Speltini
Federica
F
Maraschi
Elisa
E
Rivagli
Antonella
A
Profumo
D000900:Anti-Bacterial Agents / Q000032:analysis / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005453:Fluorescence; D024841:Fluoroquinolones / Q000032:analysis / Q000302:isolation & purification*; D008872:Microwaves; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D012989:Soil Pollutants