In the present study, a simple and rapid method for metamizole metabolite 4‐methylamino antipyrine (MAA) determination in human plasma was developed, validated and successfully applied to a clinical trial. Chromatographic separation was achieved in HILIC mode on a YMC‐Pack SIL column (100 × 2.0 mm; S‐5 μm, 30 nm), with a mobile phase consisting of acetonitrile, water and formic acid. Protein precipitation of a small plasma volume using acetonitrile was selected for sample preparation. The multiple reaction monitoring transitions in the positive ionization mode were m/z 218.2 → 56.2 for MAA and m/z 221.2 → 56.2 for MAA‐d3 (IS, internal standard). Concentration levels of MAA calibration standards were in the range of 0.100–20 μg/ml. Metamizole conversion into MAA in both water and organic media was investigated, and the level of the conversion in commercially available injection solutions was estimated.

中文翻译：

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高效液相色谱串联质谱法测定人血浆中的4-甲基氨基安替比林。

在本研究中，开发了一种简单快速的测定人血浆中间苯二酚代谢物4-甲基氨基安替比林（MAA）的方法，并将其验证并成功应用于临床试验。在YMC-Pack SIL色谱柱（100×2.0 mm; S-5μm，30 nm）上以HILIC模式进行色谱分离，流动相由乙腈，水和甲酸组成。选择使用乙腈沉淀少量血浆的蛋白质来制备样品。正离子化模式下的多反应监测转变对于MAA和m / z为m / z 218.2→56.2221.2→56.2 for MAA-d3（IS，内部标准）。MAA校准标样的浓度范围为0.100–20μg/ ml。研究了在水和有机介质中将咪唑唑转化为MAA的可能性，并估算了市售注射液中的转化水平。