In matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) analysis and imaging of lipids, comprehensive ionization of lipids simultaneously by a universal matrix is a very challenging problem. Ion suppression of readily ionizable lipids to others is common. To overcome this obstacle and enhance the coverage of MALDI MS analysis and imaging of lipids, we developed a novel strategy employing a mixture of matrices, each of which is capable of selective ionization of different lipid classes. Given that MALDI MS with either 9-aminoacridine (9-AA) or N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC) yields weak in-source decay which is critical for analysis of complex biological samples and possesses orthogonal selectivity for ionization of lipid classes, we tested the mixtures of NEDC and 9-AA with different ratios for analysis of standard lipids and mouse brain lipid extracts. We determined 1.35 of NEDC/9-AA as an optimized molar ratio. It was demonstrated that an enhanced coverage with the optimized mixture was obtained, which enabled us to analyze and map all the major classes of phospholipids and sulfatide from either lipid extracts or tissue slides, respectively. We believe that this powerful novel strategy can enhance lipidomics analysis and MALDI MS imaging of lipids in a high-throughput and semi-quantitative fashion.

中文翻译：

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通过优化基质混合物的策略，增强基质辅助激光解吸/电离质谱法对脂质分析和成像的覆盖率

在基质辅助激光解吸/电离质谱 (MALDI MS) 分析和脂质成像中，通过通用基质同时全面电离脂质是一个非常具有挑战性的问题。对其他容易电离的脂质的离子抑制是常见的。为了克服这一障碍并提高 MALDI MS 分析和脂质成像的覆盖范围，我们开发了一种采用基质混合物的新策略，每种基质都能够选择性电离不同的脂质类别。鉴于 MALDI MS 与 9-氨基吖啶 (9-AA) 或 N-(1-萘基) 乙二胺二盐酸盐 (NEDC) 产生弱的源内衰变，这对于复杂生物样品的分析至关重要，并且对脂质电离具有正交选择性班级，我们测试了不同比例的 NEDC 和 9-AA 混合物，用于分析标准脂质和小鼠脑脂质提取物。我们确定 1.35 的 NEDC/9-AA 作为优化的摩尔比。结果表明，优化混合物的覆盖范围得到了增强，这使我们能够分别从脂质提取物或组织载玻片中分析和绘制所有主要类别的磷脂和硫苷脂。我们相信这种强大的新策略可以以高通量和半定量的方式增强脂质组学分析和脂质的 MALDI MS 成像。这使我们能够分别从脂质提取物或组织载玻片中分析和绘制所有主要类别的磷脂和硫苷脂。我们相信这种强大的新策略可以以高通量和半定量的方式增强脂质组学分析和脂质的 MALDI MS 成像。这使我们能够分别从脂质提取物或组织载玻片中分析和绘制所有主要类别的磷脂和硫苷脂。我们相信这种强大的新策略可以以高通量和半定量的方式增强脂质组学分析和脂质的 MALDI MS 成像。