LC-MS/MS is widely utilized today for quantification of vitamin D in biological fluids. Mass spectrometric assays for vitamin D require very careful method optimization for precise and interference-free, accurate analyses however. Here, we explore chemical derivatization and matrix-assisted laser desorption/ionization (MALDI) as a rapid alternative for quantitative measurement of 25-hydroxyvitamin D₃ in human serum, and compare it to results from LC-MS/MS. The method implemented an automated imaging step of each MALDI spot, to locate areas of high intensity, avoid sweet spot phenomena, and thus improve precision. There was no statistically significant difference in vitamin D quantification between the MALDI-MS/MS and LC-MS/MS: mean ± standard deviation for MALDI-MS—29.4 ± 10.3 ng/mL—versus LC-MS/MS—30.3 ± 11.2 ng/mL (P = 0.128)—for the sum of the 25-hydroxyvitamin D epimers. The MALDI-based assay avoided time-consuming chromatographic separation steps and was thus much faster than the LC-MS/MS assay. It also consumed less sample, required no organic solvents, and was readily automated. In this proof-of-concept study, MALDI-MS readily demonstrated its potential for mass spectrometric quantification of vitamin D compounds in biological fluids.

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如今，LC-MS / MS被广泛用于定量生物液体中的维生素D。维生素D的质谱分析需要非常仔细的方法优化，才能进行精确且无干扰的准确分析。在这里，我们探索化学衍生化和基质辅助激光解吸/电离（MALDI）作为定量测量25-羟基维生素D ₃的快速替代方法在人血清中进行检测，并将其与LC-MS / MS的结果进行比较。该方法对每个MALDI点执行自动成像步骤，以定位高强度区域，避免出现甜点现象，从而提高精度。MALDI-MS / MS和LC-MS / MS之间的维生素D定量没有统计学上的显着差异：MALDI-MS的平均值±标准偏差-29.4±10.3 ng / mL-与LC-MS / MS的平均值– 30.3±11.2 ng / mL（P = 0.128）-25-羟基维生素D差向异构体的总和。基于MALDI的分析避免了费时的色谱分离步骤，因此比LC-MS / MS分析要快得多。它还消耗更少的样品，不需要有机溶剂，并且易于自动化。在这项概念验证研究中，MALDI-MS轻松证明了其对生物流体中维生素D化合物进行质谱定量的潜力。

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