A sensitive, selective, and quantitative method incorporating high-resolution mass spectrometry was developed for the determination of blood urea nitrogen (BUN) in bronchoalveolar lavage fluid. The method requires no sample cleanup or derivatization prior to analysis. High-performance liquid chromatography (HPLC) on a Hypersil Gold PFP column (100 × 3 mm, 3 μm particle size) connected to a C18 guard column was employed for a 10 min chromatographic separation. The detection of urea was achieved using a Thermo Scientific Q-Exactive Plus instrument incorporating selected ion monitoring (SIM) modes for the protonated adduct of urea. The urea analytical measuring range for the method is 0.047-17.134 mg/dL, resulting in a BUN analytical measurement range of 0.022-8.007 mg/dL, which allows for quantitation over 3 orders of magnitude (R2 = 0.999). In addition, the method is suitable for small sample volumes (15 μL) with a high level of accuracy, precision, and specificity.

中文翻译：

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开发用于小体积支气管肺泡灌洗液 (BALF) 中尿素氮定量的灵敏高分辨率质谱方法。

开发了一种结合高分辨率质谱的灵敏、选择性和定量方法，用于测定支气管肺泡灌洗液中的血尿素氮 (BUN)。该方法在分析前不需要样品净化或衍生化。使用连接到 C18 保护柱的 Hypersil Gold PFP 柱（100 × 3 mm，3 μm 粒径）上的高效液相色谱 (HPLC) 进行 10 分钟色谱分离。尿素的检测是使用 Thermo Scientific Q-Exactive Plus 仪器实现的，该仪器结合了尿素质子化加合物的选择离子监测 (SIM) 模式。该方法的尿素分析测量范围为 0.047-17.134 mg/dL，导致 BUN 分析测量范围为 0.022-8.007 mg/dL，允许定量超过 3 个数量级 (R2 = 0.999)。