考察了过渡金属氧化物ZnO纳米颗粒直接作为无机基质，应用于基质辅助激光解吸电离飞行时间质谱( MALDI-TOF-MS)法分析糖类、硬脂酸小分子物质的效果；同时以L-精氨酸为目标分析物，初步探讨了CuO和NiO两种纳米颗粒直接作为无机基质，对L-精氨酸选择性离子化的可行性。实验中，将待分析物与纳米颗粒悬浮液直接混合于样品板上，自然蒸干溶剂形成结晶状，采用337 nm波长的紫外激光辐照激发，在反射模式的TOF-MS条件下检测分析。结果表明， ZnO纳米颗粒作为一种半导体材料，具有较强的紫外吸收，可直接作为无机基质，能够避免使用传统基质带来的干扰，简化质谱图，尤其在负离子模式下能够提高硬脂酸离子化的峰强度。此外，通过比较CuO和NiO纳米颗粒对于L-精氨酸分析检测结果的差异性，初步实现了Cu+对L-精氨酸的选择性检出。%Transition metal oxide ZnO nanoparticles as inorganic matrix was adopted in the matrix assisted laser desorption ionization time-of-flight mass spectrometry ( MALDI-TOF-MS ) analysis of small molecule compounds including sugars and stearic acid and its performances were investigated. In addition, the feasibility of metal ion selective ionization of L-arginine by using NiO and CuO nanoparticles as matrix directly was explored initially. In the experiment, the analyte and nanoparticle suspension were mixed on the sample plate. The crystal of analyte and matrix was excited by 337 nm laser after the solvent was evaporated, and then detected under reflection mode of TOF-MS. The results indicated that ZnO nanoparticles with high UV absorption could eliminate the interference of conventional matrix, simplify the mass spectra, and enhance the peak intensity of stearic acid under negative mode. Moreover, Cu+ ion selective ionization of L-arginine was achieved in comparison of CuO and NiO as matrix for MALDI-TOF-MS analysis of L-arginine.
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