Matrix-assisted laser desorption ionization (MALDI) was introduced 35 years ago and has advanced from a general method for producing intact ions from large biomolecules to wide use in applications ranging from bacteria identification to tissue imaging. MALDI was enabled by the development of high energy pulsed lasers that create ions from solid samples for analysis by mass spectrometry. The original lasers used for MALDI were ultraviolet fixed-wavelength nitrogen and Nd:YAG lasers, and a number of additional laser sources have been subsequently introduced with wavelengths ranging from the infrared to the ultraviolet and pulse widths from nanosecond to femtosecond. Wavelength tunable sources have been employed both in the IR and UV, and repetition rates have increased from tens of Hz to tens of kHz as MALDI has moved into mass spectrometry imaging. Dual-pulse configurations have been implemented with two lasers directed at the target or with a second laser creating ions in the plume of desorbed material. This review provides a brief history of the use of lasers for ionization in mass spectrometry and describes the various types of lasers and configurations used for MALDI.

中文翻译：

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用于基质辅助激光解吸电离的激光器

基质辅助激光解吸电离（MALDI）于35年前问世，它已经从一种从大型生物分子生产完整离子的通用方法发展到了从细菌鉴定到组织成像的广泛应用。MALDI通过开发高能脉冲激光器得以实现，该激光器从固体样品中产生离子，以进行质谱分析。用于MALDI的原始激光器是紫外线固定波长氮和Nd：YAG激光器，随后又引入了许多其他的激光源，其波长范围从红外到紫外，脉冲宽度从纳秒到飞秒。在IR和UV中都使用了波长可调光源，并且随着MALDI进入质谱成像，重复频率已从数十Hz增至数十kHz。双脉冲配置已通过两个对准目标的激光器或第二个激光器在解吸材料羽流中产生离子的方式实现。这篇综述简要介绍了在质谱分析中使用激光进行电离的历史，并介绍了用于MALDI的各种类型的激光器和配置。