二氧化锆QuEChERS-高效液相色谱-串联质谱测定鱼肉中2种硝基咪唑及代谢产物

建立了QuEChERS结合液相色谱-串联质谱(HPLC-MS/MS)检测鱼肉中2种硝基咪唑类药物和1种硝基咪唑代谢产物的分析方法,考察了样品提取溶剂和二氧化锆使用量对回收率的影响。结果表明前处理最佳条件为:采用乙酸铵、0.1%氨水-乙腈振荡提取,经100 mg PSA、40 mg C₁₈、600 mg无水硫酸镁及20 mg二氧化锆净化剂净化;液质最佳条件为:0.1%甲酸水-0.1%甲酸乙腈梯度洗脱,C₁₈色谱柱(2.1 mm×50 mm)分离,正离子模式电喷雾电离,多反应离子扫描(MRM)分析目标化合物。3种药物在0.5~20 ng/mL范围内线性良好,R2≥0.998;3个添加水平(n=6),平均回收率在88.1%~107.0%范围内,相对标准偏差在2.43%~8.17%范围内;检出限在0.2~0.5 μg/kg之间,定量限在0.6~1.2 μg/kg之间。结论:该方法可有效的降低基质效应,提高分析方法的选择性及灵敏度,可用于鱼肉的硝基咪唑类药物的检测。

Determination of Nitromidazoles in Fish by QuEChERS Extraction with ZrO2Coupled to High Performance Liquid Chromatography-tandem Mass Spectrometry

A modified QuEChERS coupled with high performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of two nitromidazoles and one metabolites in fish. Key parameters that affected impurity removal and recovery of samples were optimized including the sample extraction solvent and amount of purifying agent ZrO₂. The results showed that, the optimal sample pretreatment conditions were achieved as follows:Samples were extracted with acetonitrile contained 0.1% ammonium hydroxide, and then purified with 100 mg of PSA, 40 mg of C₁₈, 600 mg of anhydrous magnesium sulfate and 20 mg zirconium dioxide. The optimal conditions were achieved as follows:The analysis was performed by an HPLC-MS/MS system with C₁₈ (2.1 mm×50 mm) column, the mobile phase consisted of 0.1% acetonitrile and 0. 1% formic acid solution by gradient elution, and multiple reaction monitoring (MRM) mode with positive electrospray ionization was used. The R2 of three drugs were higher than 0.998 in the linear range of 0.5~20 ng/mL. At three spiked levels (n=6), the percentage of drugs with recoveries ranging from 88.1% to 107.0%, and the relative standard deviations (RSDs) of 2.43%~8.17%. The limits of detection (LODs) were 0.2~0.5 μg/kg and the limits quantification (LOQs) were 0. 6~1.2 μg/kg.Conclusion:This method was accurate and rapid, and could be widely used for the quantitative detection of nitromidazoles in fish.