分散固相萃取结合液相色谱-串联质谱法测定水产品中11种四环素类药物

采用分散固相萃取结合液相色谱-串联质谱仪，建立水产品中11 种四环素类药物残留的分析方法。样品经Na2EDTA-McIIvaine缓冲溶液分散后，以体积分数1%乙酸乙腈提取，提取液经盐析及脱水后取乙腈层，用C18净化。目标物用C18色谱柱（100 mm×2.1 mm，3 μm）分离，以甲醇和体积分数0.1%甲酸水溶液为流动相进行梯度洗脱，利用电喷雾离子源多反应监测模式进行检测。结果表明：11 种化合物在各自的质量浓度范围内线性关系良好，相关系数均大于0.998；大多数化合物在定量限添加水平下的响应良好，在2 倍和5 倍定量限添加水平下平均回收率普遍大于80%，相对标准偏差为3.2%～10.3%（n=6）；检出限（RS/N=3）和定量限（RS/N=10）分别为2.9～6.1 μg/kg和10～20 μg/kg。该方法简便、快速、灵敏，适用于水产品中11 种四环素残留物的定性、定量分析。

Determination of 11 Tetracycline Residues in Aquatic Products Using Dispersive Solid Phase Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry

An analytical method using high performance liquid chromatography-tandem mass spectrometry coupled with a dispersive solid phase extraction (DSPE）procedure for sample preparation was developed to determine 11 tetracycline residues in aquatic products. The samples were dispersed in Na2EDTA-McIIvaine buffer solution and extracted with acetonitrile containing 1% (V/V) acetic acid. After that, the extract was salted out and dehydrated by adding anhydrous sodium sulfate, and the acetonitrile phase was harvested and purified using a C18 sorbent. The analytes were separated on a C18 column (100 mm × 2.1 mm, 3 μm) with gradient elution using a mobile phase containing methanol and 0.1% (V/V) formic acid aqueous solution. Mass spectrometry was performed using an electrospray ionization source in the multiple reaction monitoring (MRM) mode. The correlation coefficients of the standard calibration curves for the 11 tetracyclines were all above 0.998. Most of the compounds showed good response at the limit of quantitation (LOQ) level. The average recoveries of most compounds were more than 80% at spiked concentrations two- and five-fold higher than the LOQ, with relative standard deviations of 3.2%–10.3% (n = 6). The limits of detection (LODs, RS/N = 3) and LOQs (RS/N = 10) were 2.9–6.1 and 10–20 μg/kg, respectively. The method is simple, rapid, sensitive, and suitable for the simultaneous determination of the 11 tetracycline residues in aquatic products.