Study on Soft Ionization Effect of Femtosecond Laser Desorption Single Photon Post-Ionization Technique
10.19756/j.issn.0253-3820.241246
- VernacularTitle:飞秒激光解吸单光子后电离技术的软电离效果研究
- Author:
Quan-Feng XU
1
;
Yu-Yang ZHU
;
Yi-Xin LENG
;
Yong-Jun HU
;
Wei HANG
Author Information
1. 厦门大学化学化工学院,谱学分析与仪器教育部重点实验室,厦门 361005
- Keywords:
Laser desorption;
Post-ionization;
Single photon ionization;
Two-photon ionization;
Soft ionization
- From:
Chinese Journal of Analytical Chemistry
2024;52(10):1508-1516
- CountryChina
- Language:Chinese
-
Abstract:
Lasers are widely utilized in ion sources for mass spectrometry.They can be employed to desorb and ionize samples directly or enhance the ionization efficiency of neutral molecules through post-ionization.To investigate the ionization characteristics of the single photon ionization technique,in this work,a femtosecond laser with a wavelength of 515 nm was utilized for desorption,and a nanosecond laser with a wavelength of 118 nm for post-ionization.A laboratory-built laser desorption/laser post-ionization time-of-flight mass spectrometer(LDPI-TOFMS)was used to analyze three types of organic substances including acridines,phenothiazines,and metal porphyrins.The results demonstrated that the single photon ionization method effectively reduced the fragment generation,safeguarded the molecular ions against fragmentation,and achieved soft ionization as indicated by the adductive and characteristic molecular ions.Furthermore,a 266-nm nanosecond laser was employed as a multiphoton post-ionization source for comparison.The outcomes indicated that molecules were significantly fragmented,and more fragmented ions were generated due to the multiphoton ionization technique,which complicated the spectral analysis.The comparison further demonstrated that the single-photon post-ionization technology could be utilized to analyze a variety of organic compounds via soft ionization.LDPI-TOFMS procedure was straightforward,and did not require intricate sample preparations.The laser desorption with single photon post-ionization mass spectrometry showed potential to offer a high level of sensitivity and specificity for surfaces,thin layers,and complicated sample analysis.
