Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, 80401, United States.
Anal Chem. 2012 Sep 18;84(18):7677-83. doi: 10.1021/ac300688u. Epub 2012 Aug 27.
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been used for lipid analysis; however, one of the drawbacks of this technique is matrix interference peaks at low masses. Metal oxide surfaces are described here for direct, matrix-free analysis of small (MW < 1000 Da) lipid compounds, without interferences in the resulting spectra from traditional matrix background peaks. Spectra from lipid standards produced protonated and sodiated molecular ions. More complex mixtures including vegetable oil shortening and lipid extracts from bacterial and algal sources provided similar results. Mechanistic insight into the mode of ionization from surface spectroscopy, negative ion mass spectrometry, and stable isotope studies is also presented. The metal oxide system is compared to other reported matrix-free systems.
基质辅助激光解吸/电离质谱（MALDI-MS）已被用于脂质分析；然而，该技术的一个缺点是在低质量处存在基质干扰峰。本文介绍了金属氧化物表面，用于在没有传统基质背景峰干扰的情况下，直接、无基质分析小（MW < 1000 Da）脂质化合物。脂质标准品的光谱产生质子化和钠离子化分子离子。包括植物油起酥油和细菌和藻类来源的脂质提取物在内的更复杂混合物也提供了类似的结果。表面光谱学、负离子质谱和稳定同位素研究提供了对离子化模式的机理见解。金属氧化物系统与其他报道的无基质系统进行了比较。
