关键词: 沉积物, 氟喹诺酮, 分散固相萃取, 高效液相色谱串联质谱法, sediments, fluoroquinolones, dispersive solid-phase extraction, high performance liquid chromatography-tandem mass spectrometry

Abstract: An efficient method was established for the determination of fluoroquinolones in sediment by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with dispersive solid-phase extraction. The samples were ultrasonically extracted with 20 mL phosphate buffer solution and acetonitrile mixture (1:1, V/V), followed by 0.15 g ethylenediamine tetraacetic acid disodium salt complexation. Then the supernatant extract was cleaned up with a dispersive solid-phase extraction. The analytes were separated on a Ultimate XB-C18 column by gradient elution with 4 mmol/L ammonium acetate-0.1% formic acid -0.1% formic acid methol as mobile phase, detected in multiple reaction monitoring (MRM) with electrospray ionization (ESI) under positive ion mode. And the quantitative results were calculated by the internal standard method. The results showed that the calibration curves were linear (R2>0.99) in the range of 2.5~200 ng/mL for five fluoroquinolones. Limits of quantitation for fluoroquinolones were 2 μg/kg. The average recoveries at spiked levels of 2~50 μg/kg ranged from 79.8% to 112%. Intra-day and inter-day RSDs were 3.2%~9.9% and 5.3%~8.6%, respectively.