Recently, mass‐spectrometry methods show its utility in tumor boundary location. The effect of differences between research and clinical protocols such as low‐ and high‐resolution measurements and sample storage have to be understood and taken into account to transfer methods from bench to bedside. In this study, we demonstrate a simple way to compare mass spectra obtained by different experimental protocols, assess its quality, and check for the presence of outliers and batch effect in the dataset. We compare the mass spectra of both fresh and frozen–thawed astrocytic brain tumor samples obtained with the inline cartridge extraction prior to electrospray ionization. Our results reveal the importance of both positive and negative ion mode mass spectrometry for getting reliable information about sample diversity. We show that positive mode highlights the difference between protocols of mass spectra measurement, such as fresh and frozen–thawed samples, whereas negative mode better characterizes the histological difference between samples. We also show how the use of similarity spectrum matrix helps to identify the proper choice of the measurement parameters, so data collection would be kept reliable, and analysis would be correct and meaningful.

中文翻译：

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在线小柱萃取质谱变化的评估

最近，质谱方法显示了其在肿瘤边界定位中的实用性。必须了解并考虑研究和临床协议之间差异的影响，例如低分辨率和高分辨率测量以及样本存储，以便将方法从工作台转移到床边。在这项研究中，我们展示了一种简单的方法来比较由不同实验方案获得的质谱，评估其质量，并检查数据集中是否存在异常值和批次效应。我们比较了在电喷雾电离之前通过在线墨盒提取获得的新鲜和冻融星形胶质细胞脑肿瘤样品的质谱图。我们的结果揭示了正离子和负离子模式质谱对于获得有关样品多样性的可靠信息的重要性。我们表明，正模式突出了质谱测量方案之间的差异，例如新鲜和冻融样品，而负模式更好地表征了样品之间的组织学差异。我们还展示了使用相似谱矩阵如何帮助确定测量参数的正确选择，因此数据收集将保持可靠，分析将是正确和有意义的。