取均匀制备的样品5.00 g,用Na₂EDTA-Mcllvaine缓冲溶液超声提取15 min,经Oasis PRiME HLB固相萃取柱净化,洗脱液于45℃氮吹至近干,残渣用体积比9∶1的含0.1%(体积分数,下同)甲酸的5 mmol·L^-1乙酸铵-乙腈混合液2.0 mL溶解,经0.22 μm水相滤膜过滤后,采用高效液相色谱-串联质谱法(HPLC-MS/MS)测定其中11种喹诺酮类药物的残留量。以ZORBAX Eclipse plus C₁₈色谱柱(100 mm×2.1 mm,3.5 μm)为固定相,以不同体积比的含0.1%甲酸的5 mmol·L^-1乙酸铵溶液和乙腈的混合液为流动相进行梯度洗脱。采用电喷雾正离子源,以多反应监测(MRM)模式进行串联质谱分析,采用基质匹配的混合标准溶液系列绘制工作曲线,同位素内标法定量。结果表明:11种喹诺酮类药物工作曲线的线性范围为0.5~400.0 μg·L^-1,检出限(3S/N)为0.2~0.3 μg·kg^-1。对空白样品进行3个不同浓度水平的加标回收试验,回收率为72.2%~119%,测定值的相对标准偏差(n=6)为2.6%~9.7%。方法用于测定58批实际样品,结果显示11种喹诺酮类药物残留均未检出。

The sample uniformly prepared (5.00 g) was extracted ultrasonically for 15 min with Na₂EDTA-Mcllvaine buffer solution, purified by Oasis PRiME HLB solid phase extraction column. The eluate was blown by nitrogen until nearly dry at 45 ℃, and the residue was dissolved with 2.0 mL of a mixture of 5 mmol·L^-1 ammonium acetate solution containing 0.1% (φ, the same below) formic acid and acetonitrile at the volume ratio of 9∶1, and filtered by the 0.22 μm aqueous phase filtration membrane. The 11 quinolones residues in the sample solution were determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). ZORBAX Eclipse plus C₁₈ column (100 mm×2.1 mm, 3.5 μm) was used as stationary phase, and a mixture of 5 mmol·L^-1 ammonium acetate solution containing 0.1% formic acid and acetonitrile at different volume ratios was used as mobile phase for gradient elution. Multiple reaction monitoring (MRM) mode via positive electrospray ionization was adopted in MS/MS analysis. The working curves of matrix matched mixed standard solution series were drawn, and isotope internal standard method was used for quantitative analysis. As shown by the results, linear ranges of these working curves for 11 quinolones were 0.5-400.0 μg·L^-1, with detection limits (3S/N) in the range of 0.2-0.3 μg·kg^-1. Test for recovery was made on blank samples at the 3 concentration levels by standard addition method, giving results in the range of 72.2%-119%, with RSDs (n=6) of the determined values in the range of 2.6%-9.7%. Samples of 58 batches were determined by this method, and none of 11 quinolones were found in these samples.