中文摘要：

研制了超声喷雾电离源（SSI）。采用核糖核酸A、溶菌酶等样品和商品化的线性离子阱质谱仪对该电离源进行了表征。实验发现，对于生物大分子，超声喷雾电离质谱（SSI-MS）能够获得与电喷雾质谱（ESI-MS）类似的多电荷离子。但与同等条件下ESI-MS所获得的谱图相比，SSI主要获得低价态的多电荷离子。在此基础上，系统考察了SSI-MS各主要操作参数对不同价态蛋白质多电荷离子信号强度的影响，并提出了SSI离子化的可能机理。结果表明，在喷雾气压3．4-3．6MPa、喷雾口到质谱入口的距离4-6mm、离子传输管温度250．300℃、样液流速50-100μL／min、2％-5％甲酸酸性且不含甲醇的条件下，各价态蛋白质离子信号强度及信号分布均达到最优；而离子传输管温度越高，喷雾压力越大或溶剂中甲醇等挥发性成分越高，则越有利于低价态离子的形成。

英文摘要：

A sonic spray source （SSI）, developed in our lab, was coupled to a commercially available linear ion trap mass spectrometer for protein analysis. Mass spectra of proteins such as ribonuclease A （ RNase A） and lysozyme were obtained with substantially enhanced abundant peaks of low charge states. The effect of the operation parameters, including nebulization gas pressure, desolvation temperature, sample infusion rate, sample components etc. of the SSI source on the charge state distribution were systematically investigated. The experimental data show that SSI is apt to form multiply charged ions of proteins, but with charge states lower than those obtained with a conventional ESI source. The ion signal of RNASE is optimized under the operation conditions ： the nebulization gas pressure is 3.4 - 3.6 MPa, the distance between the spray tip and the MS inlet is 4 -6 mm , temperature of capillary is 250 -300℃ , sample flow rate of the solution （2% -5% formic acid） is 50 - 100 μL/min. It is found that the low charge states of ions is favored with high temperature of the heating capillary and high pressure of the nebulization gas pressure or high contenct of volatile constituents （e. g. methanol） of the solution.