Dai Guonian, Zhou Xuzheng, Wang Weiwei, Zhai Bintao, Li Jiang, Liu Yangling, Zhang Yong, Zhang Jiyu
College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, China.
Key Laboratory of Veterinary Pharmaceutical Development, Lanzhou Institute of Husbandry and Pharma-Ceutical Sciences, Chinese Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Lanzhou 730050, China.
Molecules. 2025 Mar 26;30(7):1473. doi: 10.3390/molecules30071473.
This study presents a novel high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for simultaneous determination of oxyclozanide (OXY) and levamisole hydrochloride (LEV) residues in ovine tissues, addressing the critical gap in cross-class antiparasitic drug monitoring. Leveraging dual solid-phase extraction strategies-MAX anion-exchange for lipophilic OXY and MCX cation-exchange for hydrophilic LEV-we achieved efficient purification of these pharmacokinetically divergent compounds from complex matrices (muscle, liver, kidney, and perirenal adipose). The method demonstrated superior sensitivity with limits of detection (1.5 μg/kg) and quantification (2.5 μg/kg) below international maximum residue limits (MRLs), validated through Codex Alimentarius guidelines (CAC/GL 71-2009). Linear responses (2.5-1000 μg/kg, R > 0.9900) and robust precision (intra-day RSD: 1.44-12.51%; inter-day RSD: 0.29-17.70%) were maintained across spiked concentrations (LOQ, 0.5×, 1×, and 2 × MRLs), with recoveries of 80.94-115.36% confirming matrix-agnostic accuracy. Stability assessments under diverse storage conditions further validated method reliability. Applied to pharmacokinetic profiling in medicated sheep, this protocol established a 28-day withdrawal period for edible tissues, reconciling regulatory compliance with food safety requirements. As the first reported simultaneous quantification platform for and antiparasitics, our methodology advances veterinary residue analytics by enabling efficient multi-class surveillance and evidence-based withdrawal period optimization.
本研究提出了一种新型高效液相色谱 - 串联质谱法（HPLC-MS/MS），用于同时测定绵羊组织中氯硝柳胺（OXY）和盐酸左旋咪唑（LEV）残留量，填补了跨类抗寄生虫药物监测方面的关键空白。利用双固相萃取策略——MAX阴离子交换用于亲脂性的OXY，MCX阳离子交换用于亲水性的LEV——我们实现了从复杂基质（肌肉、肝脏、肾脏和肾周脂肪）中高效纯化这些药代动力学特性不同的化合物。该方法具有卓越的灵敏度，检测限（1.5 μg/kg）和定量限（2.5 μg/kg）低于国际最大残留限量（MRLs），并通过食品法典委员会指南（CAC/GL 71-2009）进行了验证。在加标浓度（定量限、0.5×MRLs、1×MRLs和2×MRLs）范围内，保持了线性响应（2.5 - 1000 μg/kg，R > 0.9900）和稳健的精密度（日内相对标准偏差：1.44 - 12.51%；日间相对标准偏差：0.29 - 17.70%），回收率为80.94 - 115.36%，证实了与基质无关的准确性。在不同储存条件下的稳定性评估进一步验证了方法的可靠性。应用于用药绵羊的药代动力学分析，该方案确定了可食用组织28天的休药期，兼顾了法规合规性与食品安全要求。作为首个报道的同时定量 和 抗寄生虫药物的平台，我们的方法通过实现高效的多类监测和基于证据的休药期优化，推动了兽医残留分析的发展。
