以猪肉、猪肝、猪肾、胖头鱼、对虾和蟹为试验材料,建立了喹乙醇(OLA)的残留标示物3-甲基喹(哑)啉-2-羧酸(MQCA)残留的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法.采用0.2 mol/L盐酸提取可食性组织中的分析物,经C18固相萃取小柱净化、35℃氮气吹干及含0.19％ (v/v)甲酸的乙腈溶解后,采用超高效液相色谱分离,串联质谱法确证和定量分析.质谱检测采取正离子多反应监测模式,外标法定量.结果表明:MQCA在2～500μg/L范围内呈良好的线性关系,各组织中的相关系数(r2)均大于0.990；猪肉、猪肝、猪肾、鱼、对虾和蟹中MQCA的检出限依次为0.90、1.51、0.94、1.04、1.62和1.80μg/kg,定量限依次为3.00、5.02、3.13、3.46、5.40、6.00μg/kg.从3～ 100 μg/kg的添加浓度的检测结果可以看出,MQCA的平均回收率均在73.6％与89.0％之间,日内相对标准偏差(RSD,n=5)在15％以下,日间RSD(n=3)为20％以下.该方法的灵敏度、准确度和精密度均符合兽药残留分析技术的要求,适用于动物组织中MQCA残留的定量分析和确证检测.%An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was established for the determination of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) in animal tissues and aquatic products. The analyte was extracted with 0.2 mol/L hydrochloric acid. The extract was cleaned up on a Bond Elut C18 cartridge. Then the eluate was collected and evaporated to dryness under nitrogen gas at 35 t!. The residue was redis-solved in acetonitrile containing 0. 1% (v/v) formic acid. The identification was performed by multiple reaction monitoring in positive electrospray ionization. The quantification was done by external standard method. The calibration curves showed good linearity within the range of 2 -500 |xg/L with the correlation coefficients (r2) greater than 0. 990. The limits of detection (LODs) of MQCA in pork, swine liver, pig kidney, fish, prawn, and crab were 0.90, 1.51, 0. 94, 1. 04, 1. 62 and 1. 80 |xg/kg, respectively; and the limits of quantification (LOQs) were 3.00, 5.02, 3. 13, 3.46, 5.40 and 6.00 |xg/kg, correspondingly. The recoveries of MQCA in animal tissues and aquatic products were 73. 6% - 89. 0% at the spiked levels of 3 -100 jig/kg. The intra-day relative standard deviations (RSDs, n =5) were less than 15%, and inter-day RSDs (n =3) were less than 20%. The results demonstrated that the sensitivity, accuracy, and precision were fit for the requirements of veterinary drug residue analysis.
展开▼
