Assessment and validation of the p-QuEChERS sample preparation methodology for the analysis of >200 veterinary drugs in various animal-based food matrices

The need remains for veterinary multi-residue methods that reliably quantify and identify veterinary drugs in the various animal-based food matrices. Such a method should not only show good method performance parameters (e.g. recoveries of analytes) but must also be fast and cheap. The proposed method focused on the following points: acceptable analyte trueness (recovery) and precision for a large number (200) of diverse veterinary drugs in the relevant animal-based food matrices (egg, muscle, fatty fish, liver, kidney, and honey). The sample preparation method termed p-QuEChERS uses a salt mixture consisting of potassium phosphates to induce phase separation. The avoidance of conventional QuEChERS salts (e.g. magnesium sulphate) significantly improves recoveries of several critical analytes. Analyte recoveries were further improved by adding a centrifugation and a defatting step before initiating the salt-induced phase separation. This combined clean-up removes a large fraction of the potentially interfering matrix compounds. As a result, matrix effects in the electrospray interface were minimized. These factors were the basis for the obtained good validation data. Two types of high-resolution mass spectrometers coupled to liquid chromatography were compared for analysis. In comparison with conventional QuEChERS, the proposed p-QuEChERS concept improved the recovery of polar analytes such as penicillins, tetracyclines and quinolones. The simplicity of the procedure and the low consumable expenses make the method ideal for the routine control of veterinary drugs in all evaluated animal-based food matrices.

当前仍亟需能够在各类动物源食品基质中可靠定量与鉴定兽药的兽药多残留检测方法。此类方法不仅需具备优异的方法性能参数（如分析物回收率），还应兼具快速、低成本的优势。本研究提出的方法聚焦以下要点：在目标动物源食品基质（鸡蛋、肌肉、高脂鱼类、肝脏、肾脏及蜂蜜）中，对200余种不同兽药实现合格的分析物正确度（回收率）与精密度。该样品前处理方法命名为p-QuEChERS，采用以磷酸钾盐为主的盐混合物诱导相分离。摒弃传统QuEChERS所用盐类（如硫酸镁），可显著提升部分关键分析物的回收率。在启动盐诱导相分离前增加离心与脱脂步骤，可进一步提升分析物回收率。该联合净化步骤可去除大部分潜在干扰性基质化合物，由此将电喷雾接口中的基质效应降至最低。上述因素为获得优异的验证数据奠定了基础。本研究对比了两种与液相色谱联用的高分辨质谱仪的分析效果。与传统QuEChERS方法相比，本研究提出的p-QuEChERS策略可提升青霉素类（penicillins）、四环素类（tetracyclines）及喹诺酮类（quinolones）等极性分析物的回收率。该方法操作简便、耗材成本低廉，非常适用于所有受试动物源食品基质中兽药的常规检测。