An amphetamine interference was observed during the development of an liquid chromatography-high-resolution mass spectrometry (LC-HRMS) multi-class confirmation method for the determination of 47 drugs and metabolites in urine. The interference passed all qualitative criteria for amphetamine leading to potential false-positive results. Upon investigation, it was found that the amphetamine interference was correlated with the presence of high levels of gabapentin. Gabapentin is routinely detected in patient urine specimens at levels in excess of 1 mg/mL as it is widely prescribed at high doses and does not undergo significant metabolism. The source of the interference was identified as a gabapentin in-source fragment isomeric with protonated amphetamine. Here we describe the characterization of this interference and how its effect was mitigated in the LC-HRMS method.

中文翻译：

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LC-HRMS方法表征来自加巴喷丁的苯丙胺干扰素。

在液相色谱-高分辨率质谱法（LC-HRMS）的多类别确认方法的开发过程中，苯丙胺的干扰被观察到，该方法用于测定尿液中的47种药物和代谢物。干扰物通过了苯丙胺的所有定性标准，从而导致了潜在的假阳性结果。经调查，发现苯丙胺干扰与高水平的加巴喷丁存在有关。加巴喷丁通常在患者尿液样本中以超过1 mg / mL的水平检测到，因为它在高剂量时被广泛开处方，并且不会发生明显的新陈代谢。干扰源被鉴定为加巴喷丁的源片段与质子化的苯丙胺异构体。