Activation of MALDI plume based on non-dissociative ionization by femtosecond laser fields

本研究的目的是发展一种有效的方法，提高MALDI-MS灵敏度的基础上参与离子形成机制的反应。我们构建了一个独特的MALDI-TOF-MS系统，我们可以引入飞秒（fs）激光脉冲诱导解吸的MALDI目标或在MALDI羽由传统的纳秒（ns）紫外激光解吸产生的物种。 当聚焦飞秒激光脉冲电离DHB基质中苯丙氨酸的MALDI羽流中的中性物种时，分子离子或可识别的大碎片离子（Phe+，[Phe-COOH]+，DHB+等）在飞行时间质谱中检测到。 这意味着，使用ns-激光解吸，然后fs-激光电离的方法，使我们能够估计的中性物种的数量，这一直是未知参数的离子形成模型中的MALDI羽，并肯定会提高MALDI过程的定量分析。

The aim of this research is to develop an effective method which improves MALDI-MS sensitivity based on elementally reactions involved in ion formation mechanism. We constructed a unique MALDI-TOF-MS system to which we can introduce femtosecond(fs) laser pulses to induce desorption of MALDI targets or to ionize species in MALDI plume generated by a conventional nanosecond(ns) UV laser desorption. When neutral species in the MALDI plume of phenylalanine in DHB matrix were ionized by focused fs laser pulses, molecular ions or identifiable large fragment ions (Phe+, [Phe-COOH]+, DHB+,etc.) were detected in the TOF mass spectra. This means that the method using ns-laser desorption followed by fs-laser ionization enables us to estimate amount of neutral species, which has been unknown parameters in the ion formation model in MALDI plume, and will definitely improve the quantitative analysis of MALDI process.