Integrating Blood Microsampling Devices with CE-MS for Untargeted Analysis of Polar Metabolomics

Capillary electrophoresis–mass spectrometry (CE-MS) offers considerable advantages for polar compound metabolomics analysis, including simple workflows, fast method development, and suitability for small sample volumes. Blood microsampling (BμS) techniques (such as dried blood spots, quantitative DBS, and volumetric absorptive microsampling) are minimally invasive and have gained increased attention over the past years. Despite this growing interest, few studies have compared the metabolic profiles derived from these sampling methods and, to our best knowledge, none have employed CE-MS.
The aim of this study is to evaluate the potential of CE-MS as an analytical technique to characterize and compare the polar metabolomic profiles obtained from the three tested BμS devices to those of whole blood and plasma, which is the most used blood specimen. We compared extraction protocols based on their recovery, precision, and matrix effects for a panel of stable isotopically-labeled amino acids and acylcarnitines. Most labeled compounds showed satisfactory recovery and precision, although some matrix effects were observed in BμS device extracts.
Finally, the chosen protocol was used to assess the performance of the devices through the untargeted metabolomic analysis of samples from 10 healthy individuals. All the three BμS devices yielded very similar profiles that closely resembled that of whole blood, though remaining distinguishable from it, and from plasma. Altogether 150 compounds were annotated using a publicly available database, and differences between each BμS device, plasma and whole blood were assessed. Overall, these devices have shown to be convenient alternatives to conventional sampling in untargeted CE-MS metabolomic profiling of blood.

毛细管电泳-质谱法（Capillary electrophoresis–mass spectrometry, CE-MS）在极性化合物代谢组学分析中具备显著优势，具体包括操作流程简便、方法开发高效以及适配微量样本体积等特点。血液微量采样（Blood microsampling, BμS）技术（如干血斑、定量干血斑以及容积吸附微量采样）具有微创性，近年来受到学界日益广泛的关注。尽管此类技术的关注度持续攀升，但鲜有研究对不同采样方法得到的代谢物谱开展对比分析，而就我们所知，目前尚无研究采用毛细管电泳-质谱法进行相关探索。
本研究旨在评估毛细管电泳-质谱法作为分析技术的应用潜力，以表征并对比三种受试血液微量采样装置与全血、血浆（临床最常用的血液样本类型）所获得的极性代谢物谱。本研究针对一组稳定同位素标记的氨基酸与酰基肉碱，基于提取回收率、精密度及基质效应，对多种萃取方案进行了对比筛选。尽管在血液微量采样装置的提取物中观测到了部分基质效应，但多数标记化合物均表现出令人满意的回收率与精密度。
最后，本研究采用筛选确定的最优萃取方案，通过对10名健康个体的样本开展非靶向代谢组学分析，评估了各采样装置的性能。三种血液微量采样装置得到的代谢物谱均极为相似，且与全血代谢物谱高度接近，但仍存在可区分的差异，同时也与血浆代谢物谱存在显著区别。本研究通过公开数据库共注释得到150种化合物，并对各血液微量采样装置、血浆与全血之间的差异进行了量化评估。总体而言，在血液非靶向毛细管电泳-质谱法代谢组学分析中，此类采样装置可作为传统采样方式的便捷替代方案。