Commisso Mauro, Anesi Andrea, Dal Santo Silvia, Guzzo Flavia
Biotechnology Department, University of Verona, Strada le Grazie 15, 37134, Verona, Italy.
Rapid Commun Mass Spectrom. 2017 Feb 15;31(3):292-300. doi: 10.1002/rcm.7789.
Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are both used to generate ions for the analysis of metabolites by liquid chromatography/mass spectrometry (LC/MS). We compared the performance of these methods for the analysis of Corvina grapevine berry methanolic extracts, which are complex mixtures of diverse metabolites.
Corvina berries representing three ripening stages (veraison, early-ripening and full-ripening) were collected during two growing seasons, powdered and extracted with methanol. Untargeted metabolomic analysis was carried out by LC/ESI-MS and LC/APCI-MS. Processed data files were assembled into a data matrix for multivariate statistical analysis. The limits of detection (LODs), limits of quantification (LOQs), linear ranges, and matrix effects were investigated for strongly polar metabolites such as sucrose and tartaric acid and for moderately polar metabolites such as caftaric acid, epicatechin and quercetin 3-O-glucoside.
Multivariate statistical analysis of the 608 features revealed that APCI was particularly suitable for the ionization of strongly polar metabolites such as sugars and organic acids, whereas ESI was more suitable for moderately polar metabolites such as flavanols, flavones and both glycosylated and acylated anthocyanins. APCI generated more fragment ions whereas ESI generated more adducts. ESI achieved lower LODs and LOQs for sucrose and tartaric acid but featured narrower linear ranges and greater matrix effects.
ESI and APCI are not complementary ion sources. Indeed, ESI can be exploited to analyze moderately polar metabolites, whereas APCI can be used to investigate weakly polar/non-polar metabolites and, as demonstrated by our results, also strongly polar metabolites. ESI and APCI can be used in parallel, exploiting their strengths to cover the plant metabolome more broadly than either method alone. Copyright © 2016 John Wiley & Sons, Ltd.
电喷雾电离（ESI）和大气压化学电离（APCI）均用于通过液相色谱/质谱联用（LC/MS）产生离子以分析代谢物。我们比较了这两种方法在分析科维纳葡萄浆果甲醇提取物方面的性能，这些提取物是多种代谢物的复杂混合物。
在两个生长季节收集代表三个成熟阶段（转色期、早熟和完全成熟）的科维纳浆果，研磨成粉并用甲醇提取。通过LC/ESI-MS和LC/APCI-MS进行非靶向代谢组学分析。将处理后的数据文件组装成数据矩阵进行多变量统计分析。研究了强极性代谢物（如蔗糖和酒石酸）以及中等极性代谢物（如咖啡酸、表儿茶素和槲皮素3-O-葡萄糖苷）的检测限（LOD）、定量限（LOQ）、线性范围和基质效应。
对608个特征的多变量统计分析表明，APCI特别适合于糖和有机酸等强极性代谢物的电离，而ESI更适合于黄烷醇、黄酮以及糖基化和酰化花青素等中等极性代谢物。APCI产生更多的碎片离子，而ESI产生更多的加合物。ESI对蔗糖和酒石酸实现了更低的LOD和LOQ，但线性范围更窄且基质效应更大。
ESI和APCI不是互补的离子源。实际上，ESI可用于分析中等极性代谢物，而APCI可用于研究弱极性/非极性代谢物，并且如我们的结果所示，也可用于分析强极性代谢物。ESI和APCI可以并行使用，发挥它们的优势，比单独使用任何一种方法更广泛地覆盖植物代谢组。版权所有©2016约翰威立父子有限公司。
