Abstract: This study investigated the influence of different sample pretreatments: enhanced matrix removal-lipid (EMR-L) for lipid, Oasis PRiME hydrophile lipophilic balance (HLB) and liquid-liquid extraction (LLE) on the assay of 16 quinolone residues in porcine tissues by ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UPLC-TQ-MS/MS) or quadrupole-time-of-flight tandem mass spectrometry (Q-TOF/MS). The target compounds were quantified by the matrix-matched calibration curve. Good linearity was observed for all analytes in the range of 1.0–100.0 μg/L. The recoveries using the EMR-L and Oasis PRiME HLB methods at spiked concentration levels (5, 10 and 20?μg/kg) were 71.7%–106.9% and 70.7%–118.3% with relative standard deviations of 0.2%–16.8% and 0.1%–17.8%, respectively; the limits of quantification of the two methods were 0.13–0.56 and 0.27–1.36 μg/kg and the limits of detection were 0.04–0.23 and 0.08–0.41 μg/kg, respectively. All these figures of merit met the requirements for the determination of quinolones. In order to avoid false positive results, a suitable sample pretreatment method should be chosen for different matrix samples. The two pretreatment methods used in this study, thanks to their ease of operation, high sensitivity and good repeatability, could be suitable for the qualitative and quantitative analysis of multiple veterinary drug residues in porcine tissues.

Key words: EMR-L, Oasis PRiME HLB, liquid-liquid extraction, quinolones, porcine tissues