Abstract A rapid, simple and reliable method using amoxicillin-D4 as internal standard (IS) for determination of amoxicillin (AMO) in porcine tissues was developed. The analytical methodology used a phosphate buffer (0.01 M, pH = 6.3) with trichloroacetic acid (50 mg/mL) for extraction and Oasis® HLB cartridges for clean-up followed by UPLC-MS/MS analysis. The optimized method was validated according to EU guideline 2002/657/EC and FDA guideline. The LOQ in muscle, fat, liver and kidney were set to 10 μg/kg which was below the maximum residue limits, while the LOD were set to 5 μg/kg. Results showed that using AMO-D4 as IS can effectively eliminate relative matrix interference and improve the recovery and precision. A good linearity was observed at the range of 10−500 μg/kg with a correlation coefficients (R2) larger than 0.99. The mean recoveries were higher than 87.0 %, and the RSDs were lower than 11.2 %. This method could be applied to conveniently analysis the residue of AMO in different porcine tissues.

中文翻译：

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UPLC-MS/MS内标法快速测定猪组织中的阿莫西林

摘要 建立了一种以阿莫西林-D4 为内标(IS) 测定猪组织中阿莫西林(AMO) 的快速、简便、可靠的方法。分析方法使用含三氯乙酸 (50 mg/mL) 的磷酸盐缓冲液 (0.01 M，pH = 6.3) 进行萃取，使用 Oasis® HLB 小柱进行净化，然后进行 UPLC-MS/MS 分析。根据欧盟指南 2002/657/EC 和 FDA 指南对优化方法进行了验证。肌肉、脂肪、肝脏和肾脏中的 LOQ 设置为 10 μg/kg，低于最大残留限量，而 LOD 设置为 5 μg/kg。结果表明，使用AMO-D4作为内标可以有效消除相对基质干扰，提高回收率和精密度。在 10-500 μg/kg 范围内观察到良好的线性，相关系数 (R2) 大于 0.99。平均回收率高于 87.0%，RSD 低于 11.2%。该方法可方便地分析不同猪组织中AMO的残留量。