Serum vitamin D metabolite levels are of interest as biomarkers for vitamin D status, which has influence on numerous body functions and pathologies. The determination of vitamin D metabolite levels by liquid chromatography/mass spectrometry (LC/MS) is challenging due to their low concentrations and relatively low ionization efficiencies. Three ionization sources, dielectric barrier discharge ionization (DBDI), atmospheric pressure chemical ionization (APCI), and electrospray ionization (ESI), were compared regarding achievable limits of detection and occurring matrix effects. The latter were mainly caused by phospholipids. Therefore, in addition to a conventional solid phase extraction (SPE) stationary phase, a material for selective removal of phospholipids was examined. The selective removal of phospholipids significantly reduced observed matrix effects, especially when ESI was applied. Achievable limits of detection and observed matrix effects were lowest for APCI and with some limitations, also for DBDI.

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血清维生素D代谢物水平作为维生素D状况的生物标志物引起了人们的关注，维生素D状况对许多人体功能和病理都有影响。由于液相色谱/质谱法（LC / MS）的维生素D代谢物含量低且电离效率相对较低，因此具有挑战性。比较了三种电离源，即电介质势垒放电电离（DBDI），大气压化学电离（APCI）和电喷雾电离（ESI）的可检测极限和发生的基质效应。后者主要由磷脂引起。因此，除了常规的固相萃取（SPE）固定相外，还研究了选择性去除磷脂的材料。选择性去除磷脂显着降低了观察到的基质效应，尤其是在应用ESI时。对于APCI而言，可达到的检测限和所观察到的基质效应最低，对于DBDI也有一定的限制。

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