延时提取正交发射MALDI技术研究

在反射式飞行时间质谱仪上,采用脉冲电场延时提取技术及离子正交发射采样方式,进行了基质辅助激光解吸附电离技术(MALDI)的研究.实验所用激光波长为266nm,基质为2,5二羟基苯甲酸,样品为孔雀石绿和多肽.得到了上述样品在MALDI条件下离子的质谱图和初速度分布.质谱测量的分辨率达到4000,质量测量的线性相关度好于0.9999,平均误差小于0.0075%.

Research of Orthogonal-injection and Delayed-extraction MALDI

An orthogonal injection (OI) home-made reflectror type time-of-flight (TOF) mass spectrometer has been constructed with a matrix-assisted laser desorption/ionization (MALDI) source. Ions generated by MALDI are measured using a pulsed voltage delayed extraction method. The laser used is a frequency quadrupled Nd:YAG laser with output at wavelength of 266 nm, the matrix used here is 2,5-dihydroxybenzonic acid (DHB), and the analytes are Malachite green and peptides. Measurements of resolving power and statistical evaluation of the mass accuracy are reported here. The results indicate that resolving power in the range of 3400 to 4000 (full width at half maximum), the average error of the mass accuracy is below 0.0075%, A perfectly linear (m/z)1/2 versus t plot is found. Finally, the initial velocity distribution of analyte and matrix ions in the range of 400~1000 m/s is measured.