Histamine is an organic nitrogenous compound that acts as a neurotransmitter in the uterus, spinal cord, and brain and is involved in local immune responses. In this study, we developed a fast and simple derivatization method based on reductive amination that can be used to quantify histamine by hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. Histamine isotope analogs were synthesized via reductive amination. Histamine was modified with H2-formaldehyde to form N-dimethylated histamine to act as a standard or with D2-formaldehyde to form N-dimethylated histamine-d4 to act as an internal standard. Using this method, we achieved a limit of detection of 3.6 ng/mL, a limit of quantification of 7.9 ng/mL, and a linear calibration curve with a coefficient of determination (R2) of 0.9987. Furthermore, the intra-day relative standard deviations ranged from 0.9% to 3.7% and the inter-day relative standard deviations ranged from 2.0% to 17.6%. After derivatization, N-dimethylated histamine showed 382.5% signal enhancement compared to unmodified histamine in mass spectrometry detection. To demonstrate the applicability of this method for biological samples, we utilized standard addition method to quantify histamine in fetal bovine serum and achieved a recovery of 86.7%.

中文翻译：

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通过还原胺化和亲水相互作用液相色谱与串联质谱联用定量组胺的标准添加方法

组胺是一种有机含氮化合物，在子宫、脊髓和大脑中充当神经递质，并参与局部免疫反应。在本研究中，我们开发了一种基于还原胺化的快速简单的衍生化方法，可用于通过亲水相互作用液相色谱与串联质谱联用来定量组胺。组胺同位素类似物是通过还原胺化合成的。组胺用 H2-甲醛修饰形成 N-二甲基化组胺作为标准，或用 D2-甲醛修饰形成 N-二甲基化组胺-d4 作为内标。使用这种方法，我们实现了 3.6 ng/mL 的检测限、7.9 ng/mL 的定量限以及确定系数 (R2) 为 0.9987 的线性校准曲线。此外，日内相对标准差为0.9%至3.7%，日间相对标准差为2.0%至17.6%。衍生化后，在质谱检测中，与未修饰的组胺相比，N-二甲基化组胺显示出 382.5% 的信号增强。为了证明该方法对生物样品的适用性，我们使用标准添加方法对胎牛血清中的组胺进行定量，回收率达到 86.7%。