Matrix-enhanced surface-assisted laser desorption ionization mass spectrometry imaging (ME-SALDI MSI) has been previously demonstrated as a viable approach to improving MS imaging sensitivity. We describe here the employment of ionic matrices to replace conventional MALDI matrices as the coating layer with the aims of reducing analyte redistribution during sample preparation and improving matrix vacuum stability during imaging. In this study, CHCA/ANI (α-cyano-4-hydroxycinnamic acid/aniline) was deposited atop tissue samples through sublimation to eliminate redistribution of analytes of interest on the tissue surface. The resulting film was visually homogeneous under an optical microscope. Excellent vacuum stability of the ionic matrix was quantitatively compared with the conventional matrix. The subsequently improved ionization efficiency of the analytes over traditional MALDI was demonstrated. The benefits of using the ionic matrix in MS imaging were apparent in the analysis of garlic tissue sections in the ME-SALDI MSI mode.

基质增强表面辅助激光解吸电离质谱成像 (ME-SALDI MSI) 先前已被证明是提高 MS 成像灵敏度的可行方法。我们在这里描述了使用离子基质代替传统的 MALDI 基质作为涂层，目的是减少样品制备过程中的分析物重新分布并提高成像过程中的基质真空稳定性。在这项研究中，CHCA/ANI（α-氰基-4-羟基肉桂酸/苯胺）通过升华沉积在组织样本上，以消除感兴趣的分析物在组织表面上的重新分布。所得薄膜在光学显微镜下目视均匀。离子基质优异的真空稳定性与传统基质进行了定量比较。随后证明了分析物的电离效率高于传统 MALDI。在 ME-SALDI MSI 模式下分析大蒜组织切片时，在 MS 成像中使用离子基质的优势显而易见。