A simple, rapid, and sensitive liquid chromatography (LC)/mass spectrometry (MS) method was established and validated for simultaneous quantitation of pyrazinamide, isoniazid, rifampicin, and ethambutol in human blood sample. Samples were pretreated by a single-step precipitation with acetonitrile. Chromatographic separation was achieved on XSelecT HSS T3 column by gradient elution with a total run time of 5.0 min. MS detection was performed by a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive electrospray ionization source. Isotope-labeled internal standard, especially rifampicin-D8, was applied to adjust for the loss during sample treatment. The established LC-MS/MS method showed a wide analytical range (pyrazinamide: 1.02∼60.0 μg/mL, isoniazid: 0.152∼10.0 μg/mL, rifampicin: 0.500∼30.0 μg/mL, and ethambutol: 0.0998∼5.99 μg/mL) and a good linearity (r > 0.99 for the four analytes) with acceptable accuracy and precision (90.15%∼104.62% and 94.00%∼104.02% for intra- and interaccuracy, respectively; RSD%: <12.46% and <6.43% for intra- and interprecision, respectively). It also showed excellent recoveries (79.24%∼94.16% for all analytes) and absence of significant matrix effect. This method was successfully applied to the quantification of four first-line antituberculosis (anti-TB) drugs, suggesting its suitability for therapeutic drug monitoring in the clinical practices.

中文翻译：

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同时定量人血清中四种一线抗结核药物的LC-MS / MS方法的开发和应用。

建立了一种简单，快速，灵敏的液相色谱（LC）/质谱（MS）方法，并验证了该方法可同时定量测定人血样品中的吡嗪酰胺，异烟肼，利福平和乙胺丁醇。样品通过乙腈一步沉淀进行预处理。通过梯度洗脱在XSelecT HSS T3色谱柱上进行色谱分离，总运行时间为5.0分钟。MS检测是通过三重四极串联质谱仪以正电喷雾电离源在多反应监测模式下进行的。同位素标记的内标，尤其是利福平D8，用于调整样品处理过程中的损失。所建立的LC-MS / MS方法表现出广泛的分析范围（吡嗪酰胺：1.02~60.0  μ克/毫升，异烟肼：0.152~10.0 μ克/毫升，利福平：0.500~30.0  μ克/毫升，和乙胺丁醇：0.0998~5.99  μ克/毫升）和良好的线性度（[R  > 0.99的四种分析物）以可接受的准确度和精确度（90.15％~104.62％内部精度和内部精度分别为94.00％〜104.02％；内部精度和内部精度的RSD％：分别为<12.46％和<6.43％）。它也显示出极好的回收率（所有分析物的回收率为79.24％〜94.16％），并且没有明显的基质效应。此方法已成功应用于四种一线抗结核（TB）药物的定量分析，表明该方法适用于临床实践中的治疗药物监测。